Self-host the built-in Node.js assert tests

Also make `test-ava` work from inside the `test` directory.

Co-authored-by: Mark Wubben <mark@novemberborn.net>

test-tap/helper/cli.js

@@ -4,7 +4,6 @@ const childProcess = require('child_process');
 const getStream = require('get-stream');
 
 const cliPath = path.join(__dirname, '../../cli.js');
-const ttySimulator = path.join(__dirname, 'simulate-tty.js');
 
 function execCli(args, options, cb) {
 	let dirname;
@@ -24,9 +23,7 @@ function execCli(args, options, cb) {
 	let stderr;
 
 	const processPromise = new Promise(resolve => {
-		// Spawning a child with piped IO means that the CLI will never see a TTY.
-		// Inserting a shim here allows us to fake a TTY.
-		child = childProcess.spawn(process.execPath, ['--require', ttySimulator, cliPath].concat(args), {
+		child = childProcess.spawn(process.execPath, [cliPath].concat(args), {
 			cwd: dirname,
 			env: {AVA_FORCE_CI: 'ci', ...env}, // Force CI to ensure the correct reporter is selected
 			// env,

test/assertions/test.js

@@ -2,6 +2,6 @@ const test = require('@ava/test');
 const exec = require('../helpers/exec');
 
 test('happy path', async t => {
-	const result = await exec.fixture('happy-path.js');
+	const result = await exec.fixture(['happy-path.js']);
 	t.snapshot(result.stats.passed.map(({title}) => title));
 });

test-tap/fixture/node-assertions/assert-failure.js → test/builtin-nodejs-assert/fixtures/assert-failure.js

@@ -1,5 +1,5 @@
+const test = require('ava');
 const assert = require('assert');
-const test = require('../../..');
 
 test('test', () => {
 	assert(false);

test/builtin-nodejs-assert/fixtures/package.json

@@ -0,0 +1,7 @@
+{
+  "ava": {
+    "files": [
+      "*.js"
+    ]
+  }
+}

test/builtin-nodejs-assert/test.js

@@ -0,0 +1,25 @@
+const test = require('@ava/test');
+const exec = require('../helpers/exec');
+
+test('node assertion failures are reported to the console when running in a terminal', async t => {
+	const options = {
+		env: {
+			// The AssertionError constructor in Node.js 10 depends on the TTY interface, so opt-in
+			// to it being simulated.
+			AVA_SIMULATE_TTY: true,
+			AVA_TTY_COLOR_DEPTH: 8
+		}
+	};
+
+	const result = await t.throwsAsync(exec.fixture(['assert-failure.js'], options));
+	const error = result.stats.getError(result.stats.failed[0]);
+
+	t.true(error.values.every(value => value.formatted.includes('AssertionError')));
+});
+
+test('node assertion failures are reported to the console when not running in a terminal', async t => {
+	const result = await t.throwsAsync(exec.fixture(['assert-failure.js']));
+	const error = result.stats.getError(result.stats.failed[0]);
+
+	t.true(error.values.every(value => value.formatted.includes('AssertionError')));
+});

test/helpers/exec.js

@@ -3,8 +3,11 @@ const v8 = require('v8');
 
 const test = require('@ava/test');
 const execa = require('execa');
+const defaultsDeep = require('lodash/defaultsDeep');
 
 const cliPath = path.resolve(__dirname, '../../cli.js');
+const ttySimulator = path.join(__dirname, './simulate-tty.js');
+
 const serialization = process.versions.node >= '12.16.0' ? 'advanced' : 'json';
 
 const normalizePath = (root, file) => path.posix.normalize(path.relative(root, file));
@@ -25,15 +28,16 @@ const compareStatObjects = (a, b) => {
 	return 1;
 };
 
-exports.fixture = async (...args) => {
+exports.fixture = async (args, options = {}) => {
 	const cwd = path.join(path.dirname(test.meta.file), 'fixtures');
-	const running = execa.node(cliPath, args, {
+	const running = execa.node(cliPath, args, defaultsDeep({
 		env: {
 			AVA_EMIT_RUN_STATUS_OVER_IPC: 'I\'ll find a payphone baby / Take some time to talk to you'
 		},
 		cwd,
-		serialization
-	});
+		serialization,
+		nodeOptions: ['--require', ttySimulator]
+	}, options));
 
 	// Besides buffering stderr, if this environment variable is set, also pipe
 	// to stderr. This can be useful when debugging the tests.

test-tap/helper/simulate-tty.js → test/helpers/simulate-tty.js

@@ -5,7 +5,7 @@ const assertHasColorsArguments = count => {
 	tty.WriteStream.prototype.hasColors(count);
 };
 
-const makeHasColors = colorDepth => (count = 16, env = undefined) => {
+const makeHasColors = colorDepth => (count = 16, env) => { // eslint-disable-line default-param-last
 	// `count` is optional too, so make sure it's not an env object.
 	if (env === undefined && typeof count === 'object' && count !== null) {
 		count = 16;
@@ -15,7 +15,7 @@ const makeHasColors = colorDepth => (count = 16, env = undefined) => {
 	return count <= 2 ** colorDepth;
 };
 
-const simulateTTY = (stream, colorDepth, hasColors) => {
+const simulateTTY = (stream, colorDepth) => {
 	stream.isTTY = true;
 	stream.columns = 80;
 	stream.rows = 24;
@@ -24,9 +24,10 @@ const simulateTTY = (stream, colorDepth, hasColors) => {
 		stream.getColorDepth = () => colorDepth;
 	}
 
-	if (hasColors) {
-		stream.hasColors = makeHasColors(colorDepth);
-	}
+	stream.hasColors = makeHasColors(colorDepth);
+	stream.clearLine = tty.WriteStream.prototype.clearLine;
+	stream.cursorTo = tty.WriteStream.prototype.cursorTo;
+	stream.moveCursor = tty.WriteStream.prototype.moveCursor;
 };
 
 // The execCli helper spawns tests in a child process. This means that stdout is
@@ -36,8 +37,7 @@ if (process.env.AVA_SIMULATE_TTY) {
 	const colorDepth = process.env.AVA_TTY_COLOR_DEPTH ?
 		Number.parseInt(process.env.AVA_TTY_COLOR_DEPTH, 10) :
 		undefined;
-	const hasColors = process.env.AVA_TTY_HAS_COLORS !== undefined;
 
-	simulateTTY(process.stderr, colorDepth, hasColors);
-	simulateTTY(process.stdout, colorDepth, hasColors);
+	simulateTTY(process.stderr, colorDepth);
+	simulateTTY(process.stdout, colorDepth);
 }

test/hook-restrictions/test.js

@@ -2,13 +2,13 @@ const test = require('@ava/test');
 const exec = require('../helpers/exec');
 
 test('snapshots cannot be used in hooks', async t => {
-	const result = await t.throwsAsync(exec.fixture('invalid-snapshots-in-hooks.js'));
+	const result = await t.throwsAsync(exec.fixture(['invalid-snapshots-in-hooks.js']));
 	const error = result.stats.getError(result.stats.failedHooks[0]);
 	t.snapshot(error.message, 'error message');
 });
 
 test('`t.try()` cannot be used in hooks', async t => {
-	const result = await t.throwsAsync(exec.fixture('invalid-t-try-in-hooks.js'));
+	const result = await t.throwsAsync(exec.fixture(['invalid-t-try-in-hooks.js']));
 	const error = result.stats.getError(result.stats.failedHooks[0]);
 	t.snapshot(error.message, 'error message');
 });

test/snapshot-updates/test.js

@@ -2,14 +2,14 @@ const test = require('@ava/test');
 const exec = require('../helpers/exec');
 
 test('cannot update snapshots when file contains skipped tests', async t => {
-	const result = await t.throwsAsync(exec.fixture('contains-skip.js', '-u'));
+	const result = await t.throwsAsync(exec.fixture(['contains-skip.js', '-u']));
 	t.snapshot(result.stats.failed, 'failed tests');
 	t.snapshot(result.stats.skipped, 'skipped tests');
 	t.snapshot(result.stats.unsavedSnapshots, 'files where snapshots could not be updated');
 });
 
 test('cannot update snapshots when file contains exclusive tests', async t => {
-	const result = await exec.fixture('contains-only.js', '-u');
+	const result = await exec.fixture(['contains-only.js', '-u']);
 	t.snapshot(result.stats.failed, 'failed tests');
 	t.snapshot(result.stats.passed, 'passed tests');
 	t.snapshot(result.stats.unsavedSnapshots, 'files where snapshots could not be updated');
@@ -18,11 +18,11 @@ test('cannot update snapshots when file contains exclusive tests', async t => {
 const stripLeadingFigures = string => string.replace(/^\W+/, '');
 
 test('cannot update snapshots when matching test titles', async t => {
-	const result = await t.throwsAsync(exec.fixture('contains-skip.js', '-u', '-m=snapshot'));
+	const result = await t.throwsAsync(exec.fixture(['contains-skip.js', '-u', '-m=snapshot']));
 	t.snapshot(stripLeadingFigures(result.stderr.trim()));
 });
 
 test('cannot update snapshots when selecting tests by line number', async t => {
-	const result = await t.throwsAsync(exec.fixture('contains-skip.js:4', '-u'));
+	const result = await t.throwsAsync(exec.fixture(['contains-skip.js:4', '-u']));
 	t.snapshot(stripLeadingFigures(result.stderr.trim()));
 });

test/test-timeouts/test.js

@@ -2,13 +2,13 @@ const test = require('@ava/test');
 const exec = require('../helpers/exec');
 
 test('timeout message can be specified', async t => {
-	const result = await t.throwsAsync(exec.fixture('custom-message.js'));
+	const result = await t.throwsAsync(exec.fixture(['custom-message.js']));
 	const error = result.stats.getError(result.stats.failed[0]);
 	t.is(error.message, 'time budget exceeded');
 });
 
 test('timeout messages must be strings', async t => {
-	const result = await t.throwsAsync(exec.fixture('invalid-message.js'));
+	const result = await t.throwsAsync(exec.fixture(['invalid-message.js']));
 	const error = result.stats.getError(result.stats.failed[0]);
 	t.snapshot(error.message, 'error message');
 	t.snapshot(error.values, 'formatted values');