diff --git a/.eslintrc b/.eslintrc
index 5cc84b03..0f0ffc01 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -1,16 +1,124 @@
 {
     "root": true,
+    "env": {
+        "browser": true,
+        "node": true,
+    },
+    "extends": "@ljharb",
+    "globals": {
+        "Promise": false,
+    },
     "rules": {
+        "array-bracket-spacing": "off",
+        "complexity": "off",
+        "eqeqeq": ["error", "always", { "null": "ignore" }],
+        "func-style": "warn",
         "indent": ["error", 4],
-        "key-spacing": "error",
-        "quotes": ["error", "single", {
-            "avoidEscape": true,
-        }],
-        "semi": ["error", "always"],
-        "space-before-function-paren": ["error", {
-            "anonymous": "always",
-            "named": "never",
-        }],
-        "no-useless-escape": "error",
+        "no-magic-numbers": "off",
+        "max-lines": "warn",
+        "max-lines-per-function": "warn",
+        "max-statements": "warn",
+        "max-statements-per-line": [2, { "max": 2 }],
+        "multiline-comment-style": "off",
+        "no-param-reassign": "warn",
+        "no-negated-condition": "off",
+        "no-use-before-define": "warn",
+        "no-underscore-dangle": "warn",
+        "operator-linebreak": ["error", "before"],
+        "sort-keys": "warn",
     },
+    "ignorePatterns": [ "syntax-error.*" ],
+    "overrides": [
+        {
+            "files": ["*.mjs", "test/import/package_type/*.js"],
+            "extends": "@ljharb/eslint-config/esm",
+        },
+        {
+            "files": ["bin/**"],
+            "rules": {
+                "global-require": "off",
+                "no-process-exit": "off",
+                "quote-props": ["error", "as-needed", {
+                    "keywords": false,
+                }],
+            },
+        },
+        {
+            "files": ["bin/import-or-require.js"],
+            "parserOptions": {
+                "ecmaVersion": 2020,
+            },
+        },
+        {
+            "files": ["index.js"],
+            "rules": {
+                "no-param-reassign": "warn",
+            },
+        },
+        {
+            "files": ["lib/results.js"],
+            "rules": {
+                "no-cond-assign": "warn",
+                "no-param-reassign": "warn",
+                "no-plusplus": "warn",
+            },
+        },
+        {
+            "files": ["lib/test.js"],
+            "rules": {
+                "eqeqeq": "warn",
+                "func-name-matching": "off",
+                "max-params": "off",
+                "no-continue": "off",
+                "no-invalid-this": "off",
+                "no-param-reassign": "warn",
+                "no-plusplus": "warn",
+                "no-multi-assign": "off",
+                "no-restricted-syntax": "off",
+            },
+        },
+        {
+            "files": ["test/async-await/*"],
+            "parserOptions": {
+                "ecmaVersion": 2017,
+            },
+        },
+        {
+            "files": ["example/**", "test/**"],
+            "globals": {
+                "g": false,
+            },
+            "rules": {
+                "no-new-func": "off",
+            },
+        },
+        {
+            "files": ["example/**"],
+            "rules": {
+                "array-bracket-newline": "off",
+                "global-require": "off",
+                "no-console": "off",
+            },
+        },
+        {
+            "files": ["test/**"],
+            "rules": {
+                "dot-notation": [2, {
+                    "allowKeywords": true,
+                    "allowPattern": "throws"
+                }],
+                "id-length": "off",
+                "max-len": "off",
+                "max-lines-per-function": "off",
+                "no-plusplus": "off",
+                "no-throw-literal": "off",
+            },
+        },
+        {
+            "files": ["test/*/**"],
+            "rules": {
+                "camelcase": "off",
+            },
+        },
+    ],
 }
diff --git a/bin/tape b/bin/tape
index 3ea1cec5..a0c755a1 100755
--- a/bin/tape
+++ b/bin/tape
@@ -1,5 +1,7 @@
 #!/usr/bin/env node
 
+'use strict';
+
 var resolveModule = require('resolve').sync;
 var resolvePath = require('path').resolve;
 var readFileSync = require('fs').readFileSync;
@@ -21,9 +23,7 @@ if (typeof opts.require === 'string') {
 
 opts.require.forEach(function (module) {
     if (module) {
-        /* This check ensures we ignore `-r ""`, trailing `-r`, or
-         * other silly things the user might (inadvertently) be doing.
-         */
+        // This check ensures we ignore `-r ""`, trailing `-r`, or other silly things the user might (inadvertently) be doing.
         require(resolveModule(module, { basedir: cwd }));
     }
 });
@@ -39,8 +39,7 @@ if (typeof opts.ignore === 'string') {
 }
 
 opts._.forEach(function (arg) {
-    // If glob does not match, `files` will be an empty array.
-    // Note: `glob.sync` may throw an error and crash the node process.
+    // If glob does not match, `files` will be an empty array. Note: `glob.sync` may throw an error and crash the node process.
     var files = glob.sync(arg);
 
     if (!Array.isArray(files)) {
diff --git a/example/array.js b/example/array.js
index bec161f4..40be4847 100644
--- a/example/array.js
+++ b/example/array.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -17,13 +19,13 @@ test('array', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[ 1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
diff --git a/example/fail.js b/example/fail.js
index a0db0b11..4373c76b 100644
--- a/example/fail.js
+++ b/example/fail.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -20,10 +22,10 @@ test('array', function (t) {
         [ 3, 4 ],
         [ 1, 2, [ 3, 4 ] ],
         [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
diff --git a/example/nested.js b/example/nested.js
index 2a36f25e..299f6bb4 100644
--- a/example/nested.js
+++ b/example/nested.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -5,8 +7,8 @@ test('nested array test', function (t) {
     t.plan(5);
 
     var src = '(' + function () {
-        var xs = [ 1, 2, [ 3, 4 ] ];
-        var ys = [ 5, 6 ];
+        var xs = [1, 2, [3, 4]];
+        var ys = [5, 6];
         g([ xs, ys ]);
     } + ')()';
 
@@ -26,19 +28,19 @@ test('nested array test', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[ 1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
         },
         function (xs) {
-            t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+            t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
         }
     );
 });
diff --git a/example/nested_fail.js b/example/nested_fail.js
index ba168c7e..44ea3fd1 100644
--- a/example/nested_fail.js
+++ b/example/nested_fail.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -29,10 +31,10 @@ test('nested array test', function (t) {
         [ 3, 4 ],
         [ 1, 2, [ 3, 4 ] ],
         [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
diff --git a/example/not_enough.js b/example/not_enough.js
index fffc714f..e50ccac3 100644
--- a/example/not_enough.js
+++ b/example/not_enough.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -20,10 +22,10 @@ test('array', function (t) {
         [ 3, 4 ],
         [ 1, 2, [ 3, 4 ] ],
         [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
diff --git a/example/static/server.js b/example/static/server.js
index 80cea43d..6b1e3532 100644
--- a/example/static/server.js
+++ b/example/static/server.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var http = require('http');
 var ecstatic = require('ecstatic')(__dirname);
 var server = http.createServer(ecstatic);
diff --git a/example/stream/object.js b/example/stream/object.js
index 20f0819f..39c662ce 100644
--- a/example/stream/object.js
+++ b/example/stream/object.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 var path = require('path');
 
diff --git a/example/stream/tap.js b/example/stream/tap.js
index 9ea9ff74..53d7e232 100644
--- a/example/stream/tap.js
+++ b/example/stream/tap.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 var path = require('path');
 
diff --git a/example/stream/test/x.js b/example/stream/test/x.js
index 7dbb98ad..670baa56 100644
--- a/example/stream/test/x.js
+++ b/example/stream/test/x.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../../');
 test(function (t) {
     t.plan(1);
diff --git a/example/stream/test/y.js b/example/stream/test/y.js
index 28606d51..0a0928f2 100644
--- a/example/stream/test/y.js
+++ b/example/stream/test/y.js
@@ -1,7 +1,9 @@
+'use strict';
+
 var test = require('../../../');
 test(function (t) {
     t.plan(2);
-    t.equal(1+1, 2);
+    t.equal(1 + 1, 2);
     t.ok(true);
 });
 
diff --git a/example/timing.js b/example/timing.js
index 614c1441..4754776f 100644
--- a/example/timing.js
+++ b/example/timing.js
@@ -1,12 +1,14 @@
+'use strict';
+
 var test = require('../');
 
 test('timing test', function (t) {
     t.plan(2);
 
     t.equal(typeof Date.now, 'function');
-    var start = new Date;
+    var start = new Date();
 
     setTimeout(function () {
-        t.equal(new Date - start, 100);
+        t.equal(new Date() - start, 100);
     }, 100);
 });
diff --git a/example/too_many.js b/example/too_many.js
index cdcb5ee9..2ae76502 100644
--- a/example/too_many.js
+++ b/example/too_many.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../');
 
@@ -5,8 +7,8 @@ test('array', function (t) {
     t.plan(3);
 
     var src = '(' + function () {
-        var xs = [ 1, 2, [ 3, 4 ] ];
-        var ys = [ 5, 6 ];
+        var xs = [1, 2, [3, 4]];
+        var ys = [5, 6];
         g([ xs, ys ]);
     } + ')()';
 
@@ -17,19 +19,19 @@ test('array', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
         },
         function (xs) {
-            t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+            t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
         }
     );
 });
diff --git a/example/two.js b/example/two.js
index 78e49c37..de5b213a 100644
--- a/example/two.js
+++ b/example/two.js
@@ -1,16 +1,18 @@
+'use strict';
+
 var test = require('../');
 
 test('one', function (t) {
     t.plan(2);
     t.ok(true);
     setTimeout(function () {
-        t.equal(1+3, 4);
+        t.equal(1 + 3, 4);
     }, 100);
 });
 
 test('two', function (t) {
     t.plan(3);
-    t.equal(5, 2+3);
+    t.equal(5, 2 + 3);
     setTimeout(function () {
         t.equal('a'.charCodeAt(0), 97);
         t.ok(true);
diff --git a/index.js b/index.js
index 839cd20d..7e402af3 100644
--- a/index.js
+++ b/index.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var defined = require('defined');
 var createDefaultStream = require('./lib/default_stream');
 var Test = require('./lib/test');
@@ -5,16 +7,14 @@ var createResult = require('./lib/results');
 var through = require('through');
 
 var canEmitExit = typeof process !== 'undefined' && process
-    && typeof process.on === 'function' && process.browser !== true
-;
+    && typeof process.on === 'function' && process.browser !== true;
 var canExit = typeof process !== 'undefined' && process
-    && typeof process.exit === 'function'
-;
+    && typeof process.exit === 'function';
 
 module.exports = (function () {
-    var wait = false;
     var harness;
     var lazyLoad = function () {
+        // eslint-disable-next-line no-invalid-this
         return getHarness().apply(this, arguments);
     };
 
@@ -45,12 +45,12 @@ module.exports = (function () {
     return lazyLoad;
 
     function getHarness(opts) {
-        if (!opts) opts = {};
+        if (!opts) { opts = {}; }
         opts.autoclose = !canEmitExit;
-        if (!harness) harness = createExitHarness(opts);
+        if (!harness) { harness = createExitHarness(opts); }
         return harness;
     }
-})();
+}());
 
 function createExitHarness(conf) {
     var config = conf || {};
@@ -61,14 +61,15 @@ function createExitHarness(conf) {
     var stream = harness.createStream({ objectMode: conf.objectMode });
     var es = stream.pipe(conf.stream || createDefaultStream());
     if (canEmitExit) {
+        // eslint-disable-next-line no-unused-vars
         es.on('error', function (err) { harness._exitCode = 1; });
     }
 
     var ended = false;
     stream.on('end', function () { ended = true; });
 
-    if (config.exit === false) return harness;
-    if (!canEmitExit || !canExit) return harness;
+    if (config.exit === false) { return harness; }
+    if (!canEmitExit || !canExit) { return harness; }
 
     process.on('exit', function (code) {
         // let the process exit cleanly.
@@ -80,12 +81,13 @@ function createExitHarness(conf) {
             var only = harness._results._only;
             for (var i = 0; i < harness._tests.length; i++) {
                 var t = harness._tests[i];
-                if (only && t !== only) continue;
-                t._exit();
+                if (!only || t === only) {
+                    t._exit();
+                }
             }
         }
         harness.close();
-        process.exit(code || harness._exitCode);
+        process.exit(code || harness._exitCode); // eslint-disable-line no-process-exit
     });
 
     return harness;
@@ -111,9 +113,9 @@ function createHarness(conf_) {
                 inspectCode(st_);
             });
             st.on('result', function (r) {
-                if (!r.todo && !r.ok && typeof r !== 'string') test._exitCode = 1;
+                if (!r.todo && !r.ok && typeof r !== 'string') { test._exitCode = 1; }
             });
-        })(t);
+        }(t));
 
         results.push(t);
         return t;
@@ -136,7 +138,7 @@ function createHarness(conf_) {
 
     var only = false;
     test.only = function () {
-        if (only) throw new Error('there can only be one only test');
+        if (only) { throw new Error('there can only be one only test'); }
         only = true;
         var t = test.apply(null, arguments);
         results.only(t);
diff --git a/lib/default_stream.js b/lib/default_stream.js
index 2744258a..9e6372ec 100644
--- a/lib/default_stream.js
+++ b/lib/default_stream.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var through = require('through');
 var fs = require('fs');
 
@@ -10,20 +12,28 @@ module.exports = function () {
         for (var i = 0; i < buf.length; i++) {
             var c = typeof buf === 'string'
                 ? buf.charAt(i)
-                : String.fromCharCode(buf[i])
-            ;
-            if (c === '\n') flush();
-            else line += c;
+                : String.fromCharCode(buf[i]);
+            if (c === '\n') {
+                flush();
+            } else {
+                line += c;
+            }
         }
     }
 
     function flush() {
-        if (fs.writeSync && /^win/.test(process.platform)) {
-            try { fs.writeSync(1, line + '\n'); }
-            catch (e) { stream.emit('error', e); }
+        if (fs.writeSync && (/^win/).test(process.platform)) {
+            try {
+                fs.writeSync(1, line + '\n');
+            } catch (e) {
+                stream.emit('error', e);
+            }
         } else {
-            try { console.log(line); }
-            catch (e) { stream.emit('error', e); }
+            try {
+                console.log(line); // eslint-disable-line no-console
+            } catch (e) {
+                stream.emit('error', e);
+            }
         }
         line = '';
     }
diff --git a/lib/results.js b/lib/results.js
index 3299fbc8..29d8e242 100644
--- a/lib/results.js
+++ b/lib/results.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var defined = require('defined');
 var EventEmitter = require('events').EventEmitter;
 var inherits = require('inherits');
@@ -8,11 +10,7 @@ var callBound = require('call-bind/callBound');
 var has = require('has');
 var regexpTest = callBound('RegExp.prototype.test');
 var yamlIndicators = /:|-|\?/;
-var nextTick = typeof setImmediate !== 'undefined'
-    ? setImmediate
-    : process.nextTick
-;
-
+var nextTick = typeof setImmediate !== 'undefined' ? setImmediate : process.nextTick;
 module.exports = Results;
 inherits(Results, EventEmitter);
 
@@ -21,7 +19,7 @@ function coalesceWhiteSpaces(str) {
 }
 
 function Results() {
-    if (!(this instanceof Results)) return new Results;
+    if (!(this instanceof Results)) { return new Results(); }
     this.count = 0;
     this.fail = 0;
     this.pass = 0;
@@ -33,13 +31,14 @@ function Results() {
 }
 
 Results.prototype.createStream = function (opts) {
-    if (!opts) opts = {};
+    if (!opts) { opts = {}; }
     var self = this;
-    var output, testId = 0;
+    var output;
+    var testId = 0;
     if (opts.objectMode) {
         output = through();
         self.on('_push', function ontest(t, extra) {
-            if (!extra) extra = {};
+            if (!extra) { extra = {}; }
             var id = testId++;
             t.once('prerun', function () {
                 var row = {
@@ -81,7 +80,10 @@ Results.prototype.createStream = function (opts) {
             var t;
             while (t = getNextTest(self)) {
                 t.run();
-                if (!t.ended) return t.once('end', function () { nextTick(next); });
+                if (!t.ended) {
+                    t.once('end', function () { nextTick(next); });
+                    return;
+                }
             }
             self.emit('done');
         });
@@ -106,8 +108,11 @@ Results.prototype._watch = function (t) {
     var write = function (s) { self._stream.queue(s); };
     t.once('prerun', function () {
         var premsg = '';
-        if (t._skip) premsg = 'SKIP ';
-        else if (t._todo) premsg = 'TODO ';
+        if (t._skip) {
+            premsg = 'SKIP ';
+        } else if (t._todo) {
+            premsg = 'TODO ';
+        }
         write('# ' + premsg + coalesceWhiteSpaces(t.name) + '\n');
     });
 
@@ -117,11 +122,12 @@ Results.prototype._watch = function (t) {
             return;
         }
         write(encodeResult(res, self.count + 1));
-        self.count ++;
+        self.count++;
 
-        if (res.ok || res.todo) self.pass ++;
-        else {
-            self.fail ++;
+        if (res.ok || res.todo) {
+            self.pass++;
+        } else {
+            self.fail++;
             self.emit('fail');
         }
     });
@@ -131,16 +137,20 @@ Results.prototype._watch = function (t) {
 
 Results.prototype.close = function () {
     var self = this;
-    if (self.closed) self._stream.emit('error', new Error('ALREADY CLOSED'));
+    if (self.closed) { self._stream.emit('error', new Error('ALREADY CLOSED')); }
     self.closed = true;
     var write = function (s) { self._stream.queue(s); };
 
     write('\n1..' + self.count + '\n');
     write('# tests ' + self.count + '\n');
     write('# pass  ' + (self.pass + self.todo) + '\n');
-    if (self.todo) write('# todo  ' + self.todo + '\n');
-    if (self.fail) write('# fail  ' + self.fail + '\n');
-    else write('\n# ok\n');
+    if (self.todo) {
+        write('# todo  ' + self.todo + '\n');
+    } if (self.fail) {
+        write('# fail  ' + self.fail + '\n');
+    } else {
+        write('\n# ok\n');
+    }
 
     self._stream.queue(null);
 };
@@ -151,13 +161,13 @@ function encodeResult(res, count) {
     output += res.name ? ' ' + coalesceWhiteSpaces(res.name) : '';
 
     if (res.skip) {
-        output += ' # SKIP' + ((typeof res.skip === 'string') ? ' ' + coalesceWhiteSpaces(res.skip) : '');
+        output += ' # SKIP' + (typeof res.skip === 'string' ? ' ' + coalesceWhiteSpaces(res.skip) : '');
     } else if (res.todo) {
-        output += ' # TODO' + ((typeof res.todo === 'string') ? ' ' + coalesceWhiteSpaces(res.todo) : '');
-    };
+        output += ' # TODO' + (typeof res.todo === 'string' ? ' ' + coalesceWhiteSpaces(res.todo) : '');
+    }
 
     output += '\n';
-    if (res.ok) return output;
+    if (res.ok) { return output; }
 
     var outer = '  ';
     var inner = outer + '  ';
@@ -165,8 +175,8 @@ function encodeResult(res, count) {
     output += inner + 'operator: ' + res.operator + '\n';
 
     if (has(res, 'expected') || has(res, 'actual')) {
-        var ex = inspect(res.expected, {depth: res.objectPrintDepth});
-        var ac = inspect(res.actual, {depth: res.objectPrintDepth});
+        var ex = inspect(res.expected, { depth: res.objectPrintDepth });
+        var ac = inspect(res.actual, { depth: res.objectPrintDepth });
 
         if (Math.max(ex.length, ac.length) > 65 || invalidYaml(ex) || invalidYaml(ac)) {
             output += inner + 'expected: |-\n' + inner + '  ' + ex + '\n';
@@ -202,11 +212,12 @@ function getNextTest(results) {
 
     do {
         var t = results.tests.shift();
-        if (!t) continue;
-        if (results._only === t) {
+        if (t && results._only === t) {
             return t;
         }
     } while (results.tests.length !== 0);
+
+    return void undefined;
 }
 
 function invalidYaml(str) {
diff --git a/lib/test.js b/lib/test.js
index b002a67f..94fb175c 100644
--- a/lib/test.js
+++ b/lib/test.js
@@ -25,6 +25,7 @@ var safeClearTimeout = clearTimeout;
 
 inherits(Test, EventEmitter);
 
+// eslint-disable-next-line no-unused-vars
 var getTestArgs = function (name_, opts_, cb_) {
     var name = '(anonymous)';
     var opts = {};
@@ -41,11 +42,15 @@ var getTestArgs = function (name_, opts_, cb_) {
             cb = arg;
         }
     }
-    return { name: name, opts: opts, cb: cb };
+    return {
+        name: name,
+        opts: opts,
+        cb: cb
+    };
 };
 
 function Test(name_, opts_, cb_) {
-    if (! (this instanceof Test)) {
+    if (!(this instanceof Test)) {
         return new Test(name_, opts_, cb_);
     }
 
@@ -84,14 +89,15 @@ function Test(name_, opts_, cb_) {
                 };
             }
             return val;
-        })(this, this[prop]);
+        }(this, this[prop]));
     }
 }
 
-Test.prototype.run = function () {
+Test.prototype.run = function run() {
     this.emit('prerun');
     if (!this._cb || this._skip) {
-        return this._end();
+        this._end();
+        return;
     }
     if (this._timeout != null) {
         this.timeoutAfter(this._timeout);
@@ -136,7 +142,7 @@ Test.prototype.plan = function (n) {
 };
 
 Test.prototype.timeoutAfter = function (ms) {
-    if (!ms) throw new Error('timeoutAfter requires a timespan');
+    if (!ms) { throw new Error('timeoutAfter requires a timespan'); }
     var self = this;
     var timeout = safeSetTimeout(function () {
         self.fail(self.name + ' timed out after ' + ms + 'ms');
@@ -176,7 +182,6 @@ Test.prototype._end = function (err) {
         return;
     }
 
-
     function next(i) {
         if (i === self._teardown.length) {
             completeEnd();
@@ -207,7 +212,7 @@ Test.prototype._end = function (err) {
     }
 
     function completeEnd() {
-        if (!self.ended) self.emit('end');
+        if (!self.ended) { self.emit('end'); }
         var pendingAsserts = self._pendingAsserts();
         if (!self._planError && self._plan !== undefined && pendingAsserts) {
             self._planError = true;
@@ -221,8 +226,7 @@ Test.prototype._end = function (err) {
 };
 
 Test.prototype._exit = function () {
-    if (this._plan !== undefined &&
-        !this._planError && this.assertCount !== this._plan) {
+    if (this._plan !== undefined && !this._planError && this.assertCount !== this._plan) {
         this._planError = true;
         this.fail('plan != count', {
             expected: this._plan,
@@ -326,12 +330,11 @@ Test.prototype._assert = function assert(ok, opts) {
                 continue;
             }
 
-            // Function call description may not (just) be a function name.
-            // Try to extract function name by looking at first "word" only.
+            // Function call description may not (just) be a function name. Try to extract function name by looking at first "word" only.
             res.functionName = callDescription.split(/\s+/)[0];
             res.file = filePath;
             res.line = Number(m[3]);
-            if (m[4]) res.column = Number(m[4]);
+            if (m[4]) { res.column = Number(m[4]); }
 
             res.at = callDescription + ' (' + filePath + ')';
             break;
@@ -385,7 +388,7 @@ Test.prototype.skip = function (msg, extra) {
     });
 };
 
-function assert(value, msg, extra) {
+var tapeAssert = function assert(value, msg, extra) {
     this._assert(value, {
         message: defined(msg, 'should be truthy'),
         operator: 'ok',
@@ -393,11 +396,11 @@ function assert(value, msg, extra) {
         actual: value,
         extra: extra
     });
-}
+};
 Test.prototype.ok
 = Test.prototype['true']
 = Test.prototype.assert
-= assert;
+= tapeAssert;
 
 function notOK(value, msg, extra) {
     this._assert(!value, {
@@ -631,6 +634,7 @@ Test.prototype.doesNotMatch = function doesNotMatch(string, regexp, msg, extra)
     });
 };
 
+// eslint-disable-next-line no-unused-vars
 Test.skip = function (name_, _opts, _cb) {
     var args = getTestArgs.apply(null, arguments);
     args.opts.skip = true;
diff --git a/package.json b/package.json
index 1b8c6ab0..f1aea39e 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
         "through": "~2.3.8"
     },
     "devDependencies": {
+        "@ljharb/eslint-config": "^17.6.0",
         "array.prototype.flatmap": "^1.2.4",
         "aud": "^1.1.5",
         "concat-stream": "^1.6.2",
diff --git a/test/add-subtest-async.js b/test/add-subtest-async.js
index 12b2e2d3..9d13d44e 100644
--- a/test/add-subtest-async.js
+++ b/test/add-subtest-async.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('parent', function (t) {
diff --git a/test/anonymous-fn.js b/test/anonymous-fn.js
index f28c4340..9a73ed8a 100644
--- a/test/anonymous-fn.js
+++ b/test/anonymous-fn.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/anonymous-fn/test-wrapper.js b/test/anonymous-fn/test-wrapper.js
index 38e8ba1a..f79ef485 100644
--- a/test/anonymous-fn/test-wrapper.js
+++ b/test/anonymous-fn/test-wrapper.js
@@ -1,3 +1,5 @@
+'use strict';
+
 // Example of wrapper function that would invoke tape
 module.exports = function (testCase) {
     return function (t) {
diff --git a/test/array.js b/test/array.js
index dc4a4a40..982ddd87 100644
--- a/test/array.js
+++ b/test/array.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var tape = require('../');
 var tap = require('tap');
@@ -30,9 +32,9 @@ tap.test('array test', function (tt) {
         t.plan(5);
 
         var src = '(' + function () {
-            var xs = [ 1, 2, [ 3, 4 ] ];
-            var ys = [ 5, 6 ];
-            g([ xs, ys ]);
+            var xs = [1, 2, [3, 4]];
+            var ys = [5, 6];
+            g([xs, ys]);
         } + ')()';
 
         var output = falafel(src, function (node) {
@@ -42,19 +44,19 @@ tap.test('array test', function (tt) {
         });
 
         var arrays = [
-            [ 3, 4 ],
-            [ 1, 2, [ 3, 4 ] ],
-            [ 5, 6 ],
-            [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+            [3, 4],
+            [1, 2, [3, 4]],
+            [5, 6],
+            [[1, 2, [3, 4]], [5, 6]]
         ];
 
-        Function(['fn','g'], output)(
+        Function(['fn', 'g'], output)(
             function (xs) {
                 t.same(arrays.shift(), xs);
                 return xs;
             },
             function (xs) {
-                t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+                t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
             }
         );
     });
diff --git a/test/bound.js b/test/bound.js
index 58f26920..cff296b3 100644
--- a/test/bound.js
+++ b/test/bound.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('bind works', function (t) {
diff --git a/test/browser/asserts.js b/test/browser/asserts.js
index a1b24f6d..fb981b7c 100644
--- a/test/browser/asserts.js
+++ b/test/browser/asserts.js
@@ -1,9 +1,11 @@
+'use strict';
+
 var test = require('../../');
 
 test(function (t) {
     t.plan(4);
     t.ok(true);
-    t.equal(3, 1+2);
-    t.deepEqual([1,2,[3,4]], [1,2,[3,4]]);
-    t.notDeepEqual([1,2,[3,4,5]], [1,2,[3,4]]);
+    t.equal(3, 1 + 2);
+    t.deepEqual([1, 2, [3, 4]], [1, 2, [3, 4]]);
+    t.notDeepEqual([1, 2, [3, 4, 5]], [1, 2, [3, 4]]);
 });
diff --git a/test/child_ordering.js b/test/child_ordering.js
index 08d3c760..6c75f587 100644
--- a/test/child_ordering.js
+++ b/test/child_ordering.js
@@ -1,12 +1,14 @@
+'use strict';
+
 var test = require('../');
 
 var childRan = false;
 
 test('parent', function (t) {
-    t.test('child', function (t) {
+    t.test('child', function (st) {
         childRan = true;
-        t.pass('child ran');
-        t.end();
+        st.pass('child ran');
+        st.end();
     });
     t.end();
 });
@@ -22,22 +24,22 @@ var grandChildRan = false;
 test('grandparent', function (t) {
     t.ok(!grandParentRan, 'grand parent ran twice');
     grandParentRan = true;
-    t.test('parent', function (t) {
-        t.ok(!parentRan, 'parent ran twice');
+    t.test('parent', function (st) {
+        st.ok(!parentRan, 'parent ran twice');
         parentRan = true;
-        t.test('grandchild', function (t) {
-            t.ok(!grandChildRan, 'grand child ran twice');
+        st.test('grandchild', function (s2t) {
+            s2t.ok(!grandChildRan, 'grand child ran twice');
             grandChildRan = true;
-            t.pass('grand child ran');
-            t.end();
+            s2t.pass('grand child ran');
+            s2t.end();
         });
-        t.pass('parent ran');
-        t.end();
+        st.pass('parent ran');
+        st.end();
     });
-    t.test('other parent', function (t) {
-        t.ok(parentRan, 'first parent runs before second parent');
-        t.ok(grandChildRan, 'grandchild runs before second parent');
-        t.end();
+    t.test('other parent', function (st) {
+        st.ok(parentRan, 'first parent runs before second parent');
+        st.ok(grandChildRan, 'grandchild runs before second parent');
+        st.end();
     });
     t.pass('grandparent ran');
     t.end();
diff --git a/test/circular-things.js b/test/circular-things.js
index 46562e1a..140727ea 100644
--- a/test/circular-things.js
+++ b/test/circular-things.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/comment.js b/test/comment.js
index ff055e00..b9933b53 100644
--- a/test/comment.js
+++ b/test/comment.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var concat = require('concat-stream');
 var tap = require('tap');
 var tape = require('../');
@@ -62,7 +64,6 @@ tap.test('null argument', function (assert) {
     });
 });
 
-
 // Exploratory test, how is whitespace treated?
 tap.test('whitespace', function (assert) {
     assert.plan(1);
@@ -130,7 +131,7 @@ tap.test('non-string types', function (assert) {
         t.comment(42);
         t.comment(6.66);
         t.comment({});
-        t.comment({'answer': 42});
+        t.comment({ answer: 42 });
         function ConstructorFunction() {}
         t.comment(new ConstructorFunction());
         t.comment(ConstructorFunction);
@@ -164,11 +165,11 @@ tap.test('multiline string', function (assert) {
     test('multiline strings', function (t) {
         t.comment([
             'a',
-            'b',
+            'b'
         ].join('\n'));
         t.comment([
             'c',
-            'd',
+            'd'
         ].join('\r\n'));
         t.end();
     });
diff --git a/test/common.js b/test/common.js
index 8188fe65..eedc70ca 100644
--- a/test/common.js
+++ b/test/common.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var path = require('path');
 var yaml = require('js-yaml');
 
diff --git a/test/create_multiple_streams.js b/test/create_multiple_streams.js
index 8ecac498..9307e881 100644
--- a/test/create_multiple_streams.js
+++ b/test/create_multiple_streams.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 
 tape.test('createMultipleStreams', function (tt) {
@@ -11,7 +13,7 @@ tape.test('createMultipleStreams', function (tt) {
 
     th('test one', function (tht) {
         tht.plan(1);
-        setTimeout( function () {
+        setTimeout(function () {
             tht.pass();
             testOneComplete = true;
         }, 100);
@@ -24,8 +26,7 @@ tape.test('createMultipleStreams', function (tt) {
 
     th.onFinish(function () {
         tt.equal(th._results.count, 2, 'harness test ran');
-        tt.equal(th._results.fail,  0, "harness test didn't fail");
+        tt.equal(th._results.fail, 0, "harness test didn't fail");
     });
 });
 
-
diff --git a/test/deep-equal-failure.js b/test/deep-equal-failure.js
index b086d2c3..c227ff4b 100644
--- a/test/deep-equal-failure.js
+++ b/test/deep-equal-failure.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
@@ -64,7 +66,7 @@ tap.test('deep equal failure', function (assert) {
 
     test('deep equal', function (t) {
         t.plan(1);
-        t.equal({a: 1}, {b: 2});
+        t.equal({ a: 1 }, { b: 2 });
     });
 });
 
@@ -123,7 +125,7 @@ tap.test('deep equal failure, depth 6, with option', function (assert) {
         });
     });
 
-    test('deep equal', {objectPrintDepth: 6}, function (t) {
+    test('deep equal', { objectPrintDepth: 6 }, function (t) {
         t.plan(1);
         t.equal({ a: { a1: { a2: { a3: { a4: { a5: 1 } } } } } }, { a: { a1: { a2: { a3: { a4: { a5: 2 } } } } } });
     });
diff --git a/test/deep.js b/test/deep.js
index 909ebe10..c5820043 100644
--- a/test/deep.js
+++ b/test/deep.js
@@ -1,17 +1,19 @@
+'use strict';
+
 var test = require('../');
 
 test('deep strict equal', function (t) {
     t.notDeepEqual(
-        [ { a: '3' } ],
-        [ { a: 3 } ]
+        [{ a: '3' }],
+        [{ a: 3 }]
     );
     t.end();
 });
 
 test('deep loose equal', function (t) {
     t.deepLooseEqual(
-        [ { a: '3' } ],
-        [ { a: 3 } ]
+        [{ a: '3' }],
+        [{ a: 3 }]
     );
     t.end();
 });
diff --git a/test/double_end.js b/test/double_end.js
index f254ed35..64edb526 100644
--- a/test/double_end.js
+++ b/test/double_end.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('tap').test;
 var path = require('path');
 var concat = require('concat-stream');
@@ -18,7 +20,7 @@ test(function (t) {
         // This code is unfortunately by necessity highly coupled to node
         // versions, and may require tweaking with future versions of the timers
         // library.
-        function doEnd() { throw new Error(); };
+        function doEnd() { throw new Error(); }
         var to = setTimeout(doEnd, 5000);
         clearTimeout(to);
         to._onTimeout = doEnd;
@@ -27,8 +29,7 @@ test(function (t) {
         var atExpected;
         try {
             to._onTimeout();
-        }
-        catch (e) {
+        } catch (e) {
             stackExpected = stripFullStack(e.stack)[1];
             stackExpected = stackExpected.replace('double_end.js', 'double_end/double.js');
             stackExpected = stackExpected.trim();
diff --git a/test/double_end/double.js b/test/double_end/double.js
index 43929e51..2c0ae405 100644
--- a/test/double_end/double.js
+++ b/test/double_end/double.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 
 test('double end', function (t) {
diff --git a/test/end-as-callback.js b/test/end-as-callback.js
index a8c70940..301cad50 100644
--- a/test/end-as-callback.js
+++ b/test/end-as-callback.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var forEach = require('for-each');
 var tape = require('../');
@@ -73,14 +75,11 @@ function getStackTrace(rows) {
             if (row.indexOf('---') > -1) { // start of stack trace
                 extract = true;
             }
+        } else if (row.indexOf('...') > -1) { // end of stack trace
+            extract = false;
+            stacktrace += '  ...';
         } else {
-            if (row.indexOf('...') > -1) { // end of stack trace
-                extract = false;
-                stacktrace += '  ...';
-            } else {
-                stacktrace += row + '\n';
-            }
-
+            stacktrace += row + '\n';
         }
     });
     // console.log(stacktrace);
diff --git a/test/error.js b/test/error.js
index 83e80100..18dcb0bd 100644
--- a/test/error.js
+++ b/test/error.js
@@ -32,7 +32,7 @@ tap.test('failures', function (tt) {
             '# tests 1',
             '# pass  0',
             '# fail  1',
-            '',
+            ''
         ]);
     }));
 
diff --git a/test/exit.js b/test/exit.js
index 80ef8ad5..7c528666 100644
--- a/test/exit.js
+++ b/test/exit.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var path = require('path');
 var spawn = require('child_process').spawn;
@@ -25,7 +27,7 @@ tap.test('exit ok', function (t) {
             '',
             '# ok',
             '', // yes, these double-blank-lines at the end are required.
-            ''  // if you can figure out how to remove them, please do!
+            '' // if you can figure out how to remove them, please do!
         ].join('\n'));
     };
 
diff --git a/test/exit/fail.js b/test/exit/fail.js
index 07a65ca3..930f51df 100644
--- a/test/exit/fail.js
+++ b/test/exit/fail.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 var falafel = require('falafel');
 
@@ -5,9 +7,9 @@ test('array', function (t) {
     t.plan(5);
 
     var src = '(' + function () {
-        var xs = [ 1, 2, [ 3, 4 ] ];
-        var ys = [ 5, 6 ];
-        g([ xs, ys ]);
+        var xs = [1, 2, [3, 4]];
+        var ys = [5, 6];
+        g([xs, ys]);
     } + ')()';
 
     var output = falafel(src, function (node) {
@@ -17,19 +19,19 @@ test('array', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
         },
         function (xs) {
-            t.same(xs, [ [ 1, 2, [ 3, 4444 ] ], [ 5, 6 ] ]);
+            t.same(xs, [[1, 2, [3, 4444]], [5, 6]]);
         }
     );
 });
diff --git a/test/exit/ok.js b/test/exit/ok.js
index 6d405c7c..7649d940 100644
--- a/test/exit/ok.js
+++ b/test/exit/ok.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../../');
 
@@ -6,9 +8,9 @@ test('array', function (t) {
     t.plan(5);
 
     var src = '(' + function () {
-        var xs = [ 1, 2, [ 3, 4 ] ];
-        var ys = [ 5, 6 ];
-        g([ xs, ys ]);
+        var xs = [1, 2, [3, 4]];
+        var ys = [5, 6];
+        g([xs, ys]);
     } + ')()';
 
     var output = falafel(src, function (node) {
@@ -18,19 +20,19 @@ test('array', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
         },
         function (xs) {
-            t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+            t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
         }
     );
 });
diff --git a/test/exit/second.js b/test/exit/second.js
index 8a206bb3..79e632e2 100644
--- a/test/exit/second.js
+++ b/test/exit/second.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 
 test('first', function (t) {
diff --git a/test/exit/todo.js b/test/exit/todo.js
index acbf960a..bf0de1a8 100644
--- a/test/exit/todo.js
+++ b/test/exit/todo.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 
 test('todo pass', { todo: true }, function (t) {
diff --git a/test/exit/todo_fail.js b/test/exit/todo_fail.js
index f8ffa67c..06ec32f1 100644
--- a/test/exit/todo_fail.js
+++ b/test/exit/todo_fail.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../../');
 
 test('todo fail', { todo: true }, function (t) {
diff --git a/test/exit/too_few.js b/test/exit/too_few.js
index 68ba71db..33bc0855 100644
--- a/test/exit/too_few.js
+++ b/test/exit/too_few.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var test = require('../../');
 
@@ -5,9 +7,9 @@ test('array', function (t) {
     t.plan(6);
 
     var src = '(' + function () {
-        var xs = [ 1, 2, [ 3, 4 ] ];
-        var ys = [ 5, 6 ];
-        g([ xs, ys ]);
+        var xs = [1, 2, [3, 4]];
+        var ys = [5, 6];
+        g([xs, ys]);
     } + ')()';
 
     var output = falafel(src, function (node) {
@@ -17,19 +19,19 @@ test('array', function (t) {
     });
 
     var arrays = [
-        [ 3, 4 ],
-        [ 1, 2, [ 3, 4 ] ],
-        [ 5, 6 ],
-        [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+        [3, 4],
+        [1, 2, [3, 4]],
+        [5, 6],
+        [[1, 2, [3, 4]], [5, 6]]
     ];
 
-    Function(['fn','g'], output)(
+    Function(['fn', 'g'], output)(
         function (xs) {
             t.same(arrays.shift(), xs);
             return xs;
         },
         function (xs) {
-            t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+            t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
         }
     );
 });
diff --git a/test/exposed-harness.js b/test/exposed-harness.js
index 1056ddbc..d153eda7 100644
--- a/test/exposed-harness.js
+++ b/test/exposed-harness.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 
diff --git a/test/fail.js b/test/fail.js
index 45df8d66..7a1f7285 100644
--- a/test/fail.js
+++ b/test/fail.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var tape = require('../');
 var tap = require('tap');
@@ -47,9 +49,9 @@ tap.test('array test', function (tt) {
         t.plan(5);
 
         var src = '(' + function () {
-            var xs = [ 1, 2, [ 3, 4 ] ];
-            var ys = [ 5, 6 ];
-            g([ xs, ys ]);
+            var xs = [1, 2, [3, 4]];
+            var ys = [5, 6];
+            g([xs, ys]);
         } + ')()';
 
         var output = falafel(src, function (node) {
@@ -59,19 +61,19 @@ tap.test('array test', function (tt) {
         });
 
         var arrays = [
-            [ 3, 4 ],
-            [ 1, 2, [ 3, 4 ] ],
-            [ 5, 6 ],
-            [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+            [3, 4],
+            [1, 2, [3, 4]],
+            [5, 6],
+            [[1, 2, [3, 4]], [5, 6]]
         ];
 
-        Function(['fn','g'], output)(
+        Function(['fn', 'g'], output)(
             function (xs) {
                 t.same(arrays.shift(), xs);
                 return xs;
             },
             function (xs) {
-                t.same(xs, [ [ 1, 2, [ 3, 4444 ] ], [ 5, 6 ] ]);
+                t.same(xs, [[1, 2, [3, 4444]], [5, 6]]);
             }
         );
     });
diff --git a/test/has spaces.js b/test/has spaces.js
index 3e8c80db..990c9d88 100644
--- a/test/has spaces.js	
+++ b/test/has spaces.js	
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/ignore_from_gitignore.js b/test/ignore_from_gitignore.js
index d95260b8..8260c2ec 100644
--- a/test/ignore_from_gitignore.js
+++ b/test/ignore_from_gitignore.js
@@ -38,7 +38,7 @@ tap.test('Should pass with ignoring', { skip: process.platform === 'win32' }, fu
         ]);
     };
 
-    var ps = spawn(tapeBin, ['**/*.js', '-i', '.ignore'], {cwd: path.join(__dirname, 'ignore')});
+    var ps = spawn(tapeBin, ['**/*.js', '-i', '.ignore'], { cwd: path.join(__dirname, 'ignore') });
     ps.stdout.pipe(concat(tc));
     ps.on('exit', function (code) {
         tt.equal(code, 0); // code 0
@@ -95,7 +95,7 @@ tap.test('Should pass', { skip: process.platform === 'win32' }, function (tt) {
         ]);
     };
 
-    var ps = spawn(tapeBin, ['**/*.js'], {cwd: path.join(__dirname, 'ignore')});
+    var ps = spawn(tapeBin, ['**/*.js'], { cwd: path.join(__dirname, 'ignore') });
     ps.stdout.pipe(concat(tc));
     ps.on('exit', function (code) {
         tt.equal(code, 1);
@@ -110,10 +110,10 @@ tap.test('Should fail when ignore file does not exist', { skip: process.platform
     };
 
     var testStderr = function (rows) {
-        tt.ok(/^ENOENT[:,] no such file or directory,? (?:open )?'\$TEST\/ignore\/.gitignore'\n$/m.test(stripFullStack(rows.toString('utf8')).join('\n')));
+        tt.ok((/^ENOENT[:,] no such file or directory,? (?:open )?'\$TEST\/ignore\/.gitignore'\n$/m).test(stripFullStack(rows.toString('utf8')).join('\n')));
     };
 
-    var ps = spawn(tapeBin, ['**/*.js', '-i'], {cwd: path.join(__dirname, 'ignore')});
+    var ps = spawn(tapeBin, ['**/*.js', '-i'], { cwd: path.join(__dirname, 'ignore') });
     ps.stdout.pipe(concat(testStdout));
     ps.stderr.pipe(concat(testStderr));
     ps.on('exit', function (code) {
diff --git a/test/many.js b/test/many.js
index d6e85158..6e5368a3 100644
--- a/test/many.js
+++ b/test/many.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('many tests', function (t) {
diff --git a/test/match.js b/test/match.js
index b598b9db..407d6b5d 100644
--- a/test/match.js
+++ b/test/match.js
@@ -56,13 +56,13 @@ tap.test('match', function (tt) {
     test('match', function (t) {
         t.plan(6);
 
-        t.throws(
+        t['throws'](
             function () { t.match(/abc/, 'string'); },
             TypeError,
             'regex arg must be a regex'
         );
 
-        t.throws(
+        t['throws'](
             function () { t.match({ abc: 123 }, /abc/); },
             TypeError,
             'string arg must be a string'
@@ -150,13 +150,13 @@ tap.test('doesNotMatch', function (tt) {
     test('doesNotMatch', function (t) {
         t.plan(6);
 
-        t.throws(
+        t['throws'](
             function () { t.doesNotMatch(/abc/, 'string'); },
             TypeError,
             'regex arg must be a regex'
         );
 
-        t.throws(
+        t['throws'](
             function () { t.doesNotMatch({ abc: 123 }, /abc/); },
             TypeError,
             'string arg must be a string'
diff --git a/test/max_listeners.js b/test/max_listeners.js
index 23ebea8c..286a2b15 100644
--- a/test/max_listeners.js
+++ b/test/max_listeners.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var spawn = require('child_process').spawn;
 var path = require('path');
 
diff --git a/test/max_listeners/source.js b/test/max_listeners/source.js
index 2179f97d..137f8a1c 100644
--- a/test/max_listeners/source.js
+++ b/test/max_listeners/source.js
@@ -1,5 +1,10 @@
+'use strict';
+
 var test = require('../../');
 
-for (var i = 0; i < 11; i ++) {
-    test(function (t) { t.ok(true, 'true is truthy'); t.end(); });
+for (var i = 0; i < 11; i++) {
+    test(function (t) {
+        t.ok(true, 'true is truthy');
+        t.end();
+    });
 }
diff --git a/test/nested-async-plan-noend.js b/test/nested-async-plan-noend.js
index 1acc1416..a086d8ed 100644
--- a/test/nested-async-plan-noend.js
+++ b/test/nested-async-plan-noend.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('Harness async test support', function (t) {
diff --git a/test/nested-sync-noplan-noend.js b/test/nested-sync-noplan-noend.js
index c0e5d4ac..80a7da04 100644
--- a/test/nested-sync-noplan-noend.js
+++ b/test/nested-sync-noplan-noend.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/nested.js b/test/nested.js
index 46822594..a2b5a390 100644
--- a/test/nested.js
+++ b/test/nested.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var tape = require('../');
 var tap = require('tap');
@@ -36,9 +38,9 @@ tap.test('array test', function (tt) {
         t.plan(6);
 
         var src = '(' + function () {
-            var xs = [ 1, 2, [ 3, 4 ] ];
-            var ys = [ 5, 6 ];
-            g([ xs, ys ]);
+            var xs = [1, 2, [3, 4]];
+            var ys = [5, 6];
+            g([xs, ys]);
         } + ')()';
 
         var output = falafel(src, function (node) {
@@ -57,19 +59,19 @@ tap.test('array test', function (tt) {
         });
 
         var arrays = [
-            [ 3, 4 ],
-            [ 1, 2, [ 3, 4 ] ],
-            [ 5, 6 ],
-            [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+            [3, 4],
+            [1, 2, [3, 4]],
+            [5, 6],
+            [[1, 2, [3, 4]], [5, 6]]
         ];
 
-        Function(['fn','g'], output)(
+        Function(['fn', 'g'], output)(
             function (xs) {
                 t.same(arrays.shift(), xs);
                 return xs;
             },
             function (xs) {
-                t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+                t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
             }
         );
     });
diff --git a/test/nested2.js b/test/nested2.js
index 1612b9b6..f167df61 100644
--- a/test/nested2.js
+++ b/test/nested2.js
@@ -1,18 +1,19 @@
+'use strict';
+
 var test = require('../');
 
 test(function (t) {
     var i = 0;
-    t.test('setup', function (t) {
+    t.test('setup', function (st) {
         process.nextTick(function () {
-            t.equal(i, 0, 'called once');
+            st.equal(i, 0, 'called once');
             i++;
-            t.end();
+            st.end();
         });
     });
 
-
-    t.test('teardown', function (t) {
-        t.end();
+    t.test('teardown', function (st) {
+        st.end();
     });
 
     t.end();
diff --git a/test/no_callback.js b/test/no_callback.js
index 760ff26c..99f268b5 100644
--- a/test/no_callback.js
+++ b/test/no_callback.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('No callback.');
diff --git a/test/not-deep-equal-failure.js b/test/not-deep-equal-failure.js
index 5ac49cc9..40fcb9d9 100644
--- a/test/not-deep-equal-failure.js
+++ b/test/not-deep-equal-failure.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
@@ -64,7 +66,7 @@ tap.test('deep equal failure', function (assert) {
 
     test('not deep equal', function (t) {
         t.plan(1);
-        t.notDeepEqual({b: 2}, {b: 2});
+        t.notDeepEqual({ b: 2 }, { b: 2 });
     });
 });
 
@@ -123,7 +125,7 @@ tap.test('not deep equal failure, depth 6, with option', function (assert) {
         });
     });
 
-    test('not deep equal', {objectPrintDepth: 6}, function (t) {
+    test('not deep equal', { objectPrintDepth: 6 }, function (t) {
         t.plan(1);
         t.notDeepEqual({ a: { a1: { a2: { a3: { a4: { a5: 1 } } } } } }, { a: { a1: { a2: { a3: { a4: { a5: 1 } } } } } });
     });
diff --git a/test/not-equal-failure.js b/test/not-equal-failure.js
index bb7f9167..6db2861a 100644
--- a/test/not-equal-failure.js
+++ b/test/not-equal-failure.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/objectMode.js b/test/objectMode.js
index 33df4661..fd71d8cc 100644
--- a/test/objectMode.js
+++ b/test/objectMode.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 var forEach = require('for-each');
@@ -12,7 +14,7 @@ tap.test('object results', function (assert) {
     };
 
     printer.end = function (obj) {
-        if (obj) objects.push(obj);
+        if (obj) { objects.push(obj); }
 
         var todos = 0;
         var skips = 0;
@@ -22,21 +24,21 @@ tap.test('object results', function (assert) {
 
         assert.equal(objects.length, 13);
 
-        forEach(objects, function (obj) {
-            if (obj.type === 'assert') {
+        forEach(objects, function (object) {
+            if (object.type === 'assert') {
                 asserts++;
-            } else if (obj.type === 'test') {
-                testIds.push(obj.id);
+            } else if (object.type === 'test') {
+                testIds.push(object.id);
 
-                if (obj.skip) {
+                if (object.skip) {
                     skips++;
-                } else if (obj.todo) {
+                } else if (object.todo) {
                     todos++;
                 }
-            } else if (obj.type === 'end') {
-                endIds.push(obj.text);
+            } else if (object.type === 'end') {
+                endIds.push(object.text);
                 // test object should exist
-                assert.notEqual(testIds.indexOf(obj.test), -1);
+                assert.notEqual(testIds.indexOf(object.test), -1);
             }
         });
 
@@ -51,17 +53,17 @@ tap.test('object results', function (assert) {
 
     tape('parent', function (t1) {
         t1.equal(true, true);
-        t1.test('child1', {skip: true}, function (t2) {
+        t1.test('child1', { skip: true }, function (t2) {
             t2.equal(true, true);
             t2.equal(true, false);
             t2.end();
         });
-        t1.test('child2', {todo: true}, function (t3) {
+        t1.test('child2', { todo: true }, function (t3) {
             t3.equal(true, false);
             t3.equal(true, true);
             t3.end();
         });
-        t1.test('child3', {todo: true});
+        t1.test('child3', { todo: true });
         t1.equal(true, true);
         t1.equal(true, true);
         t1.end();
diff --git a/test/onFailure.js b/test/onFailure.js
index 666227d7..0d7c1cc0 100644
--- a/test/onFailure.js
+++ b/test/onFailure.js
@@ -1,10 +1,12 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../').createHarness();
 
-//Because this test passing depends on a failure,
-//we must direct the failing output of the inner test
+// Because this test passing depends on a failure,
+// we must direct the failing output of the inner test
 var noop = function () {};
-var mockSink = {on: noop, removeListener: noop, emit: noop, end: noop};
+var mockSink = { on: noop, removeListener: noop, emit: noop, end: noop };
 tape.createStream().pipe(mockSink);
 
 tap.test('on failure', { timeout: 1000 }, function (tt) {
diff --git a/test/onFinish.js b/test/onFinish.js
index 7881273e..db3b7609 100644
--- a/test/onFinish.js
+++ b/test/onFinish.js
@@ -1,7 +1,9 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 
-tap.test('on finish', {timeout: 1000}, function (tt) {
+tap.test('on finish', { timeout: 1000 }, function (tt) {
     tt.plan(1);
     tape.onFinish(function () {
         tt.pass('tape ended');
diff --git a/test/only-twice.js b/test/only-twice.js
index cca7c758..98008c90 100644
--- a/test/only-twice.js
+++ b/test/only-twice.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 
@@ -8,7 +10,7 @@ tap.test('only twice error', function (assert) {
         t.end();
     });
 
-    assert.throws(function () {
+    assert['throws'](function () {
         test.only('second only', function (t) {
             t.end();
         });
diff --git a/test/only.js b/test/only.js
index 41f2f839..27253efa 100644
--- a/test/only.js
+++ b/test/only.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 var concat = require('concat-stream');
@@ -18,7 +20,7 @@ tap.test('tape only test', function (tt) {
             '',
             '# ok'
         ].join('\n') + '\n');
-        tt.deepEqual(ran, [ 3 ]);
+        tt.deepEqual(ran, [3]);
 
         tt.end();
     };
diff --git a/test/only2.js b/test/only2.js
index fcf4f439..bf629978 100644
--- a/test/only2.js
+++ b/test/only2.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('only2 test 1', function (t) {
diff --git a/test/only3.js b/test/only3.js
index b192a4e0..6c73ef83 100644
--- a/test/only3.js
+++ b/test/only3.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('only3 test 1', function (t) {
diff --git a/test/only4.js b/test/only4.js
index d570b5bc..b4362124 100644
--- a/test/only4.js
+++ b/test/only4.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('only4 duplicate test name', function (t) {
diff --git a/test/only5.js b/test/only5.js
index 0e158872..abbfbe20 100644
--- a/test/only5.js
+++ b/test/only5.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test.only('only5 duplicate test name', function (t) {
diff --git a/test/order.js b/test/order.js
index 02aaa055..5c0ea715 100644
--- a/test/order.js
+++ b/test/order.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 var current = 0;
 
diff --git a/test/plan_optional.js b/test/plan_optional.js
index 680dbcbb..6731f269 100644
--- a/test/plan_optional.js
+++ b/test/plan_optional.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('plan should be optional', function (t) {
diff --git a/test/require.js b/test/require.js
index 7420bb7e..14014cdd 100644
--- a/test/require.js
+++ b/test/require.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var spawn = require('child_process').spawn;
 var concat = require('concat-stream');
@@ -62,8 +64,7 @@ tap.test('requiring multiple modules', function (t) {
 });
 
 function tape(args) {
-    var proc = require('child_process');
     var bin = __dirname + '/../bin/tape';
 
-    return proc.spawn('node', [bin].concat(args.split(' ')), { cwd: __dirname });
+    return spawn('node', [bin].concat(args.split(' ')), { cwd: __dirname });
 }
diff --git a/test/require/a.js b/test/require/a.js
index 86e0296b..f4d87453 100644
--- a/test/require/a.js
+++ b/test/require/a.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../..');
 
 tape.test('module-a', function (t) {
diff --git a/test/require/b.js b/test/require/b.js
index 808fc9e5..f7fe3b1c 100644
--- a/test/require/b.js
+++ b/test/require/b.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../..');
 
 tape.test('module-b', function (t) {
diff --git a/test/require/test-a.js b/test/require/test-a.js
index 03d5a84a..bcf15ca9 100644
--- a/test/require/test-a.js
+++ b/test/require/test-a.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../..');
 
 tape.test('test-a', function (t) {
diff --git a/test/require/test-b.js b/test/require/test-b.js
index 5069b55b..6cd57bfd 100644
--- a/test/require/test-b.js
+++ b/test/require/test-b.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../..');
 
 tape.test('test-b', function (t) {
diff --git a/test/skip.js b/test/skip.js
index 234c75a9..d0843599 100644
--- a/test/skip.js
+++ b/test/skip.js
@@ -1,5 +1,6 @@
+'use strict';
+
 var test = require('../');
-var ran = 0;
 
 var concat = require('concat-stream');
 var tap = require('tap');
@@ -30,21 +31,18 @@ tap.test('test SKIP comment', function (assert) {
 
 test('skip this', { skip: true }, function (t) {
     t.fail('this should not even run');
-    ran++;
     t.end();
 });
 
 test.skip('skip this too', function (t) {
     t.fail('this should not even run');
-    ran++;
     t.end();
 });
 
 test('skip subtest', function (t) {
-    ran++;
-    t.test('skip this', { skip: true }, function (t) {
-        t.fail('this should not even run');
-        t.end();
+    t.test('skip this', { skip: true }, function (st) {
+        st.fail('this should not even run');
+        st.end();
     });
     t.end();
 });
diff --git a/test/skip_explanation.js b/test/skip_explanation.js
index 1752dcfd..544d3056 100644
--- a/test/skip_explanation.js
+++ b/test/skip_explanation.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var test = require('../');
 var concat = require('concat-stream');
@@ -72,7 +74,8 @@ tap.test('test skip explanations', function (assert) {
         // var platform = process.platform; something like this needed
         var platform = 'win32';
 
-        t.fail('run openssl',
+        t.fail(
+            'run openssl',
             { skip: platform === 'win32' && 'Installer cannot work on windows\nand fails to add to PATH\n\n Err: (2401) denied' }
         );
         t.end();
diff --git a/test/stackTrace.js b/test/stackTrace.js
index f2e4b4e2..8ae0ee6b 100644
--- a/test/stackTrace.js
+++ b/test/stackTrace.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
@@ -28,10 +30,9 @@ tap.test('preserves stack trace with newlines', function (tt) {
     });
 
     stream.pipe(concat(function (body) {
-        var body = body.toString('utf8');
-        body = stripAt(body);
+        var strippedBody = stripAt(body.toString('utf8'));
         tt.equal(
-            body,
+            strippedBody,
             'TAP version 13\n'
             + '# multiline stack trace\n'
             + 'not ok 1 Error: Preserve stack\n'
@@ -52,7 +53,7 @@ tap.test('preserves stack trace with newlines', function (tt) {
             + '# fail  1\n'
         );
 
-        tt.deepEqual(getDiag(body), {
+        tt.deepEqual(getDiag(strippedBody), {
             stack: stackTrace,
             operator: 'error',
             expected: 'undefined',
@@ -175,9 +176,9 @@ tap.test('preserves stack trace for failed assertions', function (tt) {
     parser.once('assert', function (data) {
         tt.equal(typeof data.diag.at, 'string');
         tt.equal(typeof data.diag.stack, 'string');
-        at = data.diag.at || '';
+        var at = data.diag.at || '';
         stack = data.diag.stack || '';
-        tt.ok(/^Error: true should be false(\n    at .+)+/.exec(stack), 'stack should be a stack');
+        tt.ok((/^Error: true should be false(\n {4}at .+)+/).exec(stack), 'stack should be a stack');
         tt.deepEqual(data, {
             ok: false,
             id: 1,
@@ -193,10 +194,9 @@ tap.test('preserves stack trace for failed assertions', function (tt) {
     });
 
     stream.pipe(concat(function (body) {
-        var body = body.toString('utf8');
-        body = stripAt(body);
+        var strippedBody = stripAt(body.toString('utf8'));
         tt.equal(
-            body,
+            strippedBody,
             'TAP version 13\n'
             + '# t.equal stack trace\n'
             + 'not ok 1 true should be false\n'
@@ -206,7 +206,8 @@ tap.test('preserves stack trace for failed assertions', function (tt) {
             + '    actual:   true\n'
             + '    stack: |-\n'
             + '      '
-            + stack.replace(/\n/g, '\n      ') + '\n'
+            + stack.replace(/\n/g, '\n      ')
+            + '\n'
             + '  ...\n'
             + '\n'
             + '1..1\n'
@@ -215,7 +216,7 @@ tap.test('preserves stack trace for failed assertions', function (tt) {
             + '# fail  1\n'
         );
 
-        tt.deepEqual(getDiag(body), {
+        tt.deepEqual(getDiag(strippedBody), {
             stack: stack,
             operator: 'equal',
             expected: false,
@@ -240,9 +241,9 @@ tap.test('preserves stack trace for failed assertions where actual===falsy', fun
     parser.once('assert', function (data) {
         tt.equal(typeof data.diag.at, 'string');
         tt.equal(typeof data.diag.stack, 'string');
-        at = data.diag.at || '';
+        var at = data.diag.at || '';
         stack = data.diag.stack || '';
-        tt.ok(/^Error: false should be true(\n    at .+)+/.exec(stack), 'stack should be a stack');
+        tt.ok((/^Error: false should be true(\n {4}at .+)+/).exec(stack), 'stack should be a stack');
         tt.deepEqual(data, {
             ok: false,
             id: 1,
@@ -258,10 +259,9 @@ tap.test('preserves stack trace for failed assertions where actual===falsy', fun
     });
 
     stream.pipe(concat(function (body) {
-        var body = body.toString('utf8');
-        body = stripAt(body);
+        var strippedBody = stripAt(body.toString('utf8'));
         tt.equal(
-            body,
+            strippedBody,
             'TAP version 13\n'
             + '# t.equal stack trace\n'
             + 'not ok 1 false should be true\n'
@@ -271,7 +271,8 @@ tap.test('preserves stack trace for failed assertions where actual===falsy', fun
             + '    actual:   false\n'
             + '    stack: |-\n'
             + '      '
-            + stack.replace(/\n/g, '\n      ') + '\n'
+            + stack.replace(/\n/g, '\n      ')
+            + '\n'
             + '  ...\n'
             + '\n'
             + '1..1\n'
@@ -280,7 +281,7 @@ tap.test('preserves stack trace for failed assertions where actual===falsy', fun
             + '# fail  1\n'
         );
 
-        tt.deepEqual(getDiag(body), {
+        tt.deepEqual(getDiag(strippedBody), {
             stack: stack,
             operator: 'equal',
             expected: true,
diff --git a/test/subcount.js b/test/subcount.js
index 8985e6d8..62b94746 100644
--- a/test/subcount.js
+++ b/test/subcount.js
@@ -1,14 +1,16 @@
+'use strict';
+
 var test = require('../');
 
 test('parent test', function (t) {
     t.plan(2);
-    t.test('first child', function (t) {
-        t.plan(1);
-        t.pass('pass first child');
+    t.test('first child', function (st) {
+        st.plan(1);
+        st.pass('pass first child');
     });
 
-    t.test(function (t) {
-        t.plan(1);
-        t.pass('pass second child');
+    t.test(function (st) {
+        st.plan(1);
+        st.pass('pass second child');
     });
 });
diff --git a/test/subtest_and_async.js b/test/subtest_and_async.js
index 5d922850..a5843e53 100644
--- a/test/subtest_and_async.js
+++ b/test/subtest_and_async.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 var asyncFunction = function (callback) {
diff --git a/test/subtest_plan.js b/test/subtest_plan.js
index e0f906e5..b3063b96 100644
--- a/test/subtest_plan.js
+++ b/test/subtest_plan.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 
 test('parent', function (t) {
@@ -7,15 +9,15 @@ test('parent', function (t) {
 
     t.pass('assertion in parent');
 
-    t.test('first child', function (t) {
-        t.plan(1);
-        t.pass('pass first child');
+    t.test('first child', function (st) {
+        st.plan(1);
+        st.pass('pass first child');
         firstChildRan = true;
     });
 
-    t.test('second child', function (t) {
-        t.plan(2);
-        t.ok(firstChildRan, 'first child ran first');
-        t.pass('pass second child');
+    t.test('second child', function (st) {
+        st.plan(2);
+        st.ok(firstChildRan, 'first child ran first');
+        st.pass('pass second child');
     });
 });
diff --git a/test/teardown.js b/test/teardown.js
index 51f16498..f804f8c6 100644
--- a/test/teardown.js
+++ b/test/teardown.js
@@ -95,7 +95,7 @@ tap.test('teardowns', function (tt) {
                     '          [... stack stripped ...]',
                     '  ...',
                     i > 0 ? [] : [
-                        'not ok '+ (offset + 1) +' plan != count',
+                        'not ok ' + (offset + 1) + ' plan != count',
                         '  ---',
                         '    operator: fail',
                         '    expected: 1',
@@ -120,14 +120,16 @@ tap.test('teardowns', function (tt) {
                 '# success (promise) teardown: 3'
             ] : [
                 '# SKIP success (promise)'
-            ], [
+            ],
+            [
                 '',
                 '1..' + ((typeof Promise === 'function' ? 1 : 0) + 10 + v.nonFunctions.length),
                 '# tests ' + ((typeof Promise === 'function' ? 1 : 0) + 10 + v.nonFunctions.length),
                 '# pass  ' + ((typeof Promise === 'function' ? 1 : 0) + 5),
                 '# fail  ' + (5 + v.nonFunctions.length),
                 ''
-            ]));
+            ]
+        ));
     }));
 
     test('success', function (t) {
diff --git a/test/throws.js b/test/throws.js
index 5cad0334..a683bfcf 100644
--- a/test/throws.js
+++ b/test/throws.js
@@ -1,19 +1,18 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
 
 var stripFullStack = require('./common').stripFullStack;
 
-function fn() {
-    throw new TypeError('RegExp');
-}
-
 function getNonFunctionMessage(fn) {
     try {
         fn();
     } catch (e) {
         return e.message;
     }
+    return '';
 }
 
 var getter = function () { return 'message'; };
@@ -41,7 +40,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage() + "] message: '" + getNonFunctionMessage() + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage(undefined) + '',
+            String('      TypeError: ' + getNonFunctionMessage(undefined)),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -55,7 +54,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage(null) + "] message: '" + getNonFunctionMessage(null) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage(null) + '',
+            String('      TypeError: ' + getNonFunctionMessage(null)),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -69,7 +68,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage(true) + "] message: '" + getNonFunctionMessage(true) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage(true) + '',
+            String('      TypeError: ' + getNonFunctionMessage(true)),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -83,7 +82,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage(false) + "] message: '" + getNonFunctionMessage(false) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage(false) + '',
+            String('      TypeError: ' + getNonFunctionMessage(false)),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -97,7 +96,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage('abc') + "] message: '" + getNonFunctionMessage('abc') + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage('abc') + '',
+            String('      TypeError: ' + getNonFunctionMessage('abc')),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -111,7 +110,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage(/a/g) + "] message: '" + getNonFunctionMessage(/a/g) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage(/a/g) + '',
+            String('      TypeError: ' + getNonFunctionMessage(/a/g)),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -125,7 +124,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage([]) + "] message: '" + getNonFunctionMessage([]) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage([]) + '',
+            String('      TypeError: ' + getNonFunctionMessage([])),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -139,7 +138,7 @@ tap.test('failures', function (tt) {
             '      { [TypeError: ' + getNonFunctionMessage({}) + "] message: '" + getNonFunctionMessage({}) + "' }",
             '    at: Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '    stack: |-',
-            '      TypeError: ' + getNonFunctionMessage({}) + '',
+            String('      TypeError: ' + getNonFunctionMessage({})),
             '          [... stack stripped ...]',
             '          at Test.<anonymous> ($TEST/throws.js:$LINE:$COL)',
             '          [... stack stripped ...]',
@@ -188,38 +187,38 @@ tap.test('failures', function (tt) {
 
     test('non functions', function (t) {
         t.plan(8);
-        t.throws();
-        t.throws(null);
-        t.throws(true);
-        t.throws(false);
-        t.throws('abc');
-        t.throws(/a/g);
-        t.throws([]);
-        t.throws({});
+        t['throws']();
+        t['throws'](null);
+        t['throws'](true);
+        t['throws'](false);
+        t['throws']('abc');
+        t['throws'](/a/g);
+        t['throws']([]);
+        t['throws']({});
     });
 
     test('function', function (t) {
         t.plan(1);
-        t.throws(function () {});
+        t['throws'](function () {});
     });
 
     test('custom error messages', function (t) {
         t.plan(3);
         t.equal(Object.prototype.propertyIsEnumerable.call(messageGetterError, 'message'), true, '"message" is enumerable');
-        t.throws(thrower, "{ custom: 'error', message: 'message' }");
+        t['throws'](thrower, "{ custom: 'error', message: 'message' }");
         t.equal(Object.getOwnPropertyDescriptor(messageGetterError, 'message').get, getter, 'getter is still the same');
     });
 
     test('throws null', function (t) {
         t.plan(1);
-        t.throws(function () { throw null; }, 'throws null');
+        t['throws'](function () { throw null; }, 'throws null');
         t.end();
     });
 
     test('wrong type of error', function (t) {
         t.plan(1);
         var actual = new RangeError('actual!');
-        t.throws(function () { throw actual; }, TypeError, 'throws actual');
+        t['throws'](function () { throw actual; }, TypeError, 'throws actual');
         t.end();
     });
 });
diff --git a/test/timeout.js b/test/timeout.js
index b74b11a1..bf11242d 100644
--- a/test/timeout.js
+++ b/test/timeout.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var test = require('../');
 var ran = 0;
 
diff --git a/test/timeoutAfter.js b/test/timeoutAfter.js
index 366b5d6f..10a0fe4d 100644
--- a/test/timeoutAfter.js
+++ b/test/timeoutAfter.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');
diff --git a/test/todo.js b/test/todo.js
index 5b9351ee..fe25481a 100644
--- a/test/todo.js
+++ b/test/todo.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 var concat = require('concat-stream');
diff --git a/test/todo_explanation.js b/test/todo_explanation.js
index 225d584f..72c559ed 100644
--- a/test/todo_explanation.js
+++ b/test/todo_explanation.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 var concat = require('concat-stream');
@@ -5,7 +7,7 @@ var concat = require('concat-stream');
 var common = require('./common');
 var stripFullStack = common.stripFullStack;
 
-tap.test('tape todo test', { todo: process.versions.node.match(/0\.8\.\d+/) ? 'Fails on node 0.8': false }, function (assert) {
+tap.test('tape todo test', { todo: process.versions.node.match(/0\.8\.\d+/) ? 'Fails on node 0.8' : false }, function (assert) {
     var test = tape.createHarness({ exit: false });
     assert.plan(1);
 
diff --git a/test/todo_single.js b/test/todo_single.js
index 0359bcfa..d9da7eaa 100644
--- a/test/todo_single.js
+++ b/test/todo_single.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tap = require('tap');
 var tape = require('../');
 var concat = require('concat-stream');
diff --git a/test/too_many.js b/test/too_many.js
index 6ac3e164..86131d85 100644
--- a/test/too_many.js
+++ b/test/too_many.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var falafel = require('falafel');
 var tape = require('../');
 var tap = require('tap');
@@ -48,9 +50,9 @@ tap.test('array test', function (tt) {
         t.plan(3);
 
         var src = '(' + function () {
-            var xs = [ 1, 2, [ 3, 4 ] ];
-            var ys = [ 5, 6 ];
-            g([ xs, ys ]);
+            var xs = [1, 2, [3, 4]];
+            var ys = [5, 6];
+            g([xs, ys]);
         } + ')()';
 
         var output = falafel(src, function (node) {
@@ -60,19 +62,19 @@ tap.test('array test', function (tt) {
         });
 
         var arrays = [
-            [ 3, 4 ],
-            [ 1, 2, [ 3, 4 ] ],
-            [ 5, 6 ],
-            [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ],
+            [3, 4],
+            [1, 2, [3, 4]],
+            [5, 6],
+            [[1, 2, [3, 4]], [5, 6]]
         ];
 
-        Function(['fn','g'], output)(
+        Function(['fn', 'g'], output)(
             function (xs) {
                 t.same(arrays.shift(), xs);
                 return xs;
             },
             function (xs) {
-                t.same(xs, [ [ 1, 2, [ 3, 4 ] ], [ 5, 6 ] ]);
+                t.same(xs, [[1, 2, [3, 4]], [5, 6]]);
             }
         );
     });
diff --git a/test/undef.js b/test/undef.js
index 5b219d99..42846a29 100644
--- a/test/undef.js
+++ b/test/undef.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var tape = require('../');
 var tap = require('tap');
 var concat = require('concat-stream');