From d09c4688130e322e83c3511872ee616889b5e3b8 Mon Sep 17 00:00:00 2001
From: Frederik Ring <frederik.ring@gmail.com>
Date: Fri, 17 Sep 2021 19:25:51 +0200
Subject: [PATCH] Allow reading bundle from stdin (#269)

* Allow to read bundled tests from stdin

* Validate config right after merging

* Factor out config validation into own module

* Improve naming around ambiguous items

* Consolidate option validation logic

* Throw directly when config validation fails
---
 cli/README.md                       | 18 +++++++++++++
 cli/index.js                        | 27 ++++++++++++-------
 cli/test/jsdom.integration.js       | 22 +++++++++++++++
 cli/test/playwright.integration.js  | 26 ++++++++++++++++++
 cli/test/puppeteer.integration.js   | 22 +++++++++++++++
 mochify/index.js                    | 14 ++++------
 mochify/lib/load-config.js          |  4 ++-
 mochify/lib/resolve-bundle.js       | 22 ++++++++++++---
 mochify/lib/resolve-spec.js         |  4 +++
 mochify/lib/resolve-spec.test.js    |  7 +++++
 mochify/lib/validate-config.js      | 21 +++++++++++++++
 mochify/lib/validate-config.test.js | 42 +++++++++++++++++++++++++++++
 12 files changed, 206 insertions(+), 23 deletions(-)
 create mode 100644 mochify/lib/validate-config.js
 create mode 100644 mochify/lib/validate-config.test.js

diff --git a/cli/README.md b/cli/README.md
index 5df12889..c3b99e52 100644
--- a/cli/README.md
+++ b/cli/README.md
@@ -64,3 +64,21 @@ Files in the given directory will be served as static assets.
 
 Options to pass to the server in case `--serve` or `--esm` is being used.
 Currently only `--server-option.port` for passing the port to use is supported.
+
+## Spec
+
+The `spec` argument can be a list of files or a glob pattern that will be resolved by Mochify.
+
+```
+mochify ./src/foo.test.js ./src/bar.test.js
+mochify ./src/*.test.js # Let the shell handle glob expansion
+mochify "./src/*.test.js" # Let Mochify handle glob expansion
+```
+
+### Reading a bundle from `stdin`
+
+When given `-` as the spec, Mochify expects to read a bundled test suite from `stdin`:
+
+```
+browserify -t babelify ./src/*.test.js | mochify -
+```
diff --git a/cli/index.js b/cli/index.js
index 5c8d59f8..71389857 100755
--- a/cli/index.js
+++ b/cli/index.js
@@ -72,6 +72,10 @@ const opts = yargs(hideBin(process.argv))
     '$0 --config mochify.webdriver.js "./src/**/*.test.js" ',
     'Run all tests matching the given spec using the configuration from mochify.webdriver.js.'
   )
+  .example(
+    'browserify "./src/**/*.test.js"  | $0 -',
+    'Read a bundled test suite from stdin.'
+  )
   .epilogue(
     `Mochify Resources:
 GitHub: https://github.com/mantoni/mochify.js`
@@ -86,16 +90,19 @@ if (opts['server-option']) {
   opts.server_options = opts['server-option'];
 }
 
-(async () => {
-  if (opts._.length) {
+if (opts._.length) {
+  if (opts._[0] === '-') {
+    opts.spec = process.stdin;
+  } else {
     opts.spec = opts._;
   }
-  delete opts._;
-  try {
-    const { exit_code } = await mochify(opts);
+}
+delete opts._;
+mochify(opts)
+  .catch((err) => {
+    console.error(err.stack);
+    return { exit_code: 1 };
+  })
+  .then(({ exit_code }) => {
     process.exitCode = exit_code;
-  } catch (e) {
-    console.error(e.stack);
-    process.exitCode = 1;
-  }
-})();
+  });
diff --git a/cli/test/jsdom.integration.js b/cli/test/jsdom.integration.js
index a110f10b..2ef67181 100644
--- a/cli/test/jsdom.integration.js
+++ b/cli/test/jsdom.integration.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const fs = require('fs');
 const path = require('path');
 const { assert } = require('@sinonjs/referee-sinon');
 const execa = require('execa');
@@ -28,6 +29,27 @@ describe('jsdom', () => {
     assert.equals(json.tests[0].fullTitle, 'test passes');
   });
 
+  it('reads from stdin', async () => {
+    let result;
+    try {
+      const cp = execa('../../index.js', ['--driver', 'jsdom', '-'], {
+        cwd: path.join(__dirname, 'fixture')
+      });
+      const fixture = fs.createReadStream(
+        path.resolve(__dirname, './fixture/passes.js')
+      );
+      fixture.pipe(cp.stdin);
+      result = await cp;
+    } catch (err) {
+      result = err;
+    }
+
+    assert.isFalse(result.failed);
+    const json = JSON.parse(result.stdout);
+    assert.equals(json.tests.length, 1);
+    assert.equals(json.tests[0].fullTitle, 'test passes');
+  });
+
   it('fails', async () => {
     const result = await run('fails.js');
 
diff --git a/cli/test/playwright.integration.js b/cli/test/playwright.integration.js
index 7c19ec54..d48292d9 100644
--- a/cli/test/playwright.integration.js
+++ b/cli/test/playwright.integration.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const fs = require('fs');
 const path = require('path');
 const { assert } = require('@sinonjs/referee-sinon');
 const execa = require('execa');
@@ -35,6 +36,31 @@ describe('playwright', () => {
     assert.equals(json.tests[0].fullTitle, 'test passes');
   });
 
+  it('reads from stdin', async () => {
+    let result;
+    try {
+      const cp = execa(
+        '../../index.js',
+        ['--driver', 'playwright', '--driver-option.engine', 'firefox', '-'],
+        {
+          cwd: path.join(__dirname, 'fixture')
+        }
+      );
+      const fixture = fs.createReadStream(
+        path.resolve(__dirname, './fixture/passes.js')
+      );
+      fixture.pipe(cp.stdin);
+      result = await cp;
+    } catch (err) {
+      result = err;
+    }
+
+    assert.isFalse(result.failed);
+    const json = JSON.parse(result.stdout);
+    assert.equals(json.tests.length, 1);
+    assert.equals(json.tests[0].fullTitle, 'test passes');
+  });
+
   it('fails', async () => {
     const result = await run('fails.js');
 
diff --git a/cli/test/puppeteer.integration.js b/cli/test/puppeteer.integration.js
index f917b839..1a396d68 100644
--- a/cli/test/puppeteer.integration.js
+++ b/cli/test/puppeteer.integration.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const fs = require('fs');
 const path = require('path');
 const { assert } = require('@sinonjs/referee-sinon');
 const execa = require('execa');
@@ -28,6 +29,27 @@ describe('puppeteer', () => {
     assert.equals(json.tests[0].fullTitle, 'test passes');
   });
 
+  it('reads from stdin', async () => {
+    let result;
+    try {
+      const cp = execa('../../index.js', ['--driver', 'puppeteer', '-'], {
+        cwd: path.join(__dirname, 'fixture')
+      });
+      const fixture = fs.createReadStream(
+        path.resolve(__dirname, './fixture/passes.js')
+      );
+      fixture.pipe(cp.stdin);
+      result = await cp;
+    } catch (err) {
+      result = err;
+    }
+
+    assert.isFalse(result.failed);
+    const json = JSON.parse(result.stdout);
+    assert.equals(json.tests.length, 1);
+    assert.equals(json.tests[0].fullTitle, 'test passes');
+  });
+
   it('fails', async () => {
     const result = await run('fails.js');
 
diff --git a/mochify/index.js b/mochify/index.js
index b787463b..2b323f49 100644
--- a/mochify/index.js
+++ b/mochify/index.js
@@ -2,6 +2,7 @@
 
 const { readFile } = require('fs').promises;
 const { loadConfig } = require('./lib/load-config');
+const { validateConfig } = require('./lib/validate-config');
 const { setupClient } = require('./lib/setup-client');
 const { createMochaRunner } = require('./lib/mocha-runner');
 const { resolveBundle } = require('./lib/resolve-bundle');
@@ -13,12 +14,13 @@ exports.mochify = mochify;
 
 async function mochify(options = {}) {
   const config = await loadConfig(options);
+  validateConfig(config);
 
   // Create runner early to verify the reporter exists:
   const mocha_runner = createMochaRunner(config.reporter || 'spec');
   const { mochifyDriver } = resolveMochifyDriver(config.driver);
 
-  const [mocha, client, files] = await Promise.all([
+  const [mocha, client, resolved_spec] = await Promise.all([
     readFile(require.resolve('mocha/mocha.js'), 'utf8'),
     readFile(require.resolve('./client'), 'utf8'),
     resolveSpec(config.spec)
@@ -30,7 +32,7 @@ async function mochify(options = {}) {
   let server = null;
   if (config.serve || config.esm) {
     const _scripts = [mocha, configured_client];
-    const _modules = config.esm ? files : [];
+    const _modules = config.esm ? resolved_spec : [];
     server = await startServer(
       config.serve || process.cwd(),
       Object.assign({ _scripts, _modules }, config.server_options)
@@ -41,7 +43,7 @@ async function mochify(options = {}) {
   const driver_promise = mochifyDriver(driver_options);
   const bundler_promise = config.esm
     ? Promise.resolve('')
-    : resolveBundle(config.bundle, files);
+    : resolveBundle(config.bundle, resolved_spec);
 
   let driver, bundle;
   try {
@@ -72,12 +74,6 @@ async function mochify(options = {}) {
 }
 
 function resolveMochifyDriver(name) {
-  if (!name) {
-    throw new Error(
-      'Specifying a driver option is required. Mochify drivers need to be installed separately from the API or the CLI.'
-    );
-  }
-
   let driverModule;
   try {
     // eslint-disable-next-line node/global-require
diff --git a/mochify/lib/load-config.js b/mochify/lib/load-config.js
index 7cc3b907..1b39890a 100644
--- a/mochify/lib/load-config.js
+++ b/mochify/lib/load-config.js
@@ -22,7 +22,9 @@ async function loadConfig(options) {
 async function mergeWithDefault(default_config_promise, config) {
   const default_config = await default_config_promise;
   if (default_config) {
-    return deepmerge(default_config.config, config);
+    return deepmerge(default_config.config, config, {
+      clone: false
+    });
   }
   return config;
 }
diff --git a/mochify/lib/resolve-bundle.js b/mochify/lib/resolve-bundle.js
index f5777c74..7f01ec4d 100644
--- a/mochify/lib/resolve-bundle.js
+++ b/mochify/lib/resolve-bundle.js
@@ -6,14 +6,21 @@ const { parseArgsStringToArgv } = require('string-argv');
 
 exports.resolveBundle = resolveBundle;
 
-async function resolveBundle(command, files) {
+async function resolveBundle(command, resolved_spec) {
+  if (
+    typeof resolved_spec === 'object' &&
+    typeof resolved_spec.pipe === 'function'
+  ) {
+    return bufferStream(resolved_spec);
+  }
+
   if (!command) {
-    return concatFiles(files);
+    return concatFiles(resolved_spec);
   }
 
   const [cmd, ...args] = parseArgsStringToArgv(command);
 
-  const result = await execa(cmd, args.concat(files), {
+  const result = await execa(cmd, args.concat(resolved_spec), {
     preferLocal: true
   });
 
@@ -28,3 +35,12 @@ async function concatFiles(files) {
   const buffers = await Promise.all(files.map((file) => fs.readFile(file)));
   return Buffer.concat(buffers).toString('utf8');
 }
+
+function bufferStream(stream) {
+  return new Promise((resolve, reject) => {
+    const buffers = [];
+    stream.on('data', (chunk) => buffers.push(chunk));
+    stream.on('error', (err) => reject(err));
+    stream.on('end', () => resolve(Buffer.concat(buffers).toString('utf8')));
+  });
+}
diff --git a/mochify/lib/resolve-spec.js b/mochify/lib/resolve-spec.js
index f71581a8..e3dd0a04 100644
--- a/mochify/lib/resolve-spec.js
+++ b/mochify/lib/resolve-spec.js
@@ -6,6 +6,10 @@ const glob = promisify(require('glob'));
 exports.resolveSpec = resolveSpec;
 
 async function resolveSpec(spec = 'test/**/*.js') {
+  if (typeof spec === 'object' && typeof spec.pipe === 'function') {
+    return spec;
+  }
+
   const patterns = Array.isArray(spec) ? spec : [spec];
   const matches = await Promise.all(patterns.map((pattern) => glob(pattern)));
   return matches.reduce((all, match) => all.concat(match), []);
diff --git a/mochify/lib/resolve-spec.test.js b/mochify/lib/resolve-spec.test.js
index 6c2c0224..4d90d305 100644
--- a/mochify/lib/resolve-spec.test.js
+++ b/mochify/lib/resolve-spec.test.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const fs = require('fs');
 const proxyquire = require('proxyquire');
 const { assert, sinon } = require('@sinonjs/referee-sinon');
 
@@ -75,4 +76,10 @@ describe('mochify/lib/resolve-spec', () => {
 
     await assert.rejects(promise, error);
   });
+
+  it('passes through streams', async () => {
+    const stream = fs.createReadStream(__filename);
+    const promise = resolveSpec(stream);
+    await assert.resolves(promise, stream);
+  });
 });
diff --git a/mochify/lib/validate-config.js b/mochify/lib/validate-config.js
new file mode 100644
index 00000000..0223bf7d
--- /dev/null
+++ b/mochify/lib/validate-config.js
@@ -0,0 +1,21 @@
+'use strict';
+
+exports.validateConfig = validateConfig;
+
+function validateConfig(config) {
+  if (!config.driver) {
+    throw new Error(
+      'Specifying a `driver` is required. Mochify drivers need to be installed separately from the API or the CLI.'
+    );
+  }
+  if (config.esm && config.bundle) {
+    throw new Error('`esm` cannot be used in conjunction with `bundle`');
+  }
+  if (
+    config.bundle &&
+    typeof config.spec === 'object' &&
+    typeof config.spec.pipe === 'function'
+  ) {
+    throw new Error('`bundle` cannot be used when `spec` is a stream.');
+  }
+}
diff --git a/mochify/lib/validate-config.test.js b/mochify/lib/validate-config.test.js
new file mode 100644
index 00000000..f6a6cfd6
--- /dev/null
+++ b/mochify/lib/validate-config.test.js
@@ -0,0 +1,42 @@
+'use strict';
+
+const fs = require('fs');
+const { assert, refute } = require('@sinonjs/referee-sinon');
+const { validateConfig } = require('./validate-config');
+
+describe('mochify/lib/validate-config', () => {
+  it('returns an error when esm and bundle are given', () => {
+    assert.exception(() => {
+      validateConfig({
+        driver: 'puppeteer',
+        esm: true,
+        bundle: 'browserify',
+        spec: './test.js'
+      });
+    });
+  });
+
+  it('returns an error when bundle and a stream spec are given', () => {
+    assert.exception(() => {
+      validateConfig({
+        driver: 'puppeteer',
+        bundle: 'browserify',
+        spec: fs.createReadStream(__filename)
+      });
+    });
+  });
+
+  it('returns an error on an empty config', () => {
+    assert.exception(() => validateConfig({}));
+  });
+
+  it('returns null on a valid config', () => {
+    refute.exception(() => {
+      validateConfig({
+        bundle: 'browserify -t babelify',
+        spec: './test.js',
+        driver: 'puppeteer'
+      });
+    });
+  });
+});