From a0b1f6b401abae2fbc5a8987061644adfaa7b482 Mon Sep 17 00:00:00 2001
From: Jan Scheffler <janscheffler@chromium.org>
Date: Tue, 14 Sep 2021 17:21:06 +0200
Subject: [PATCH] feat: add unit test support for bisect (#7553)

---
 CONTRIBUTING.md |  6 +++-
 utils/bisect.js | 93 ++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 81 insertions(+), 18 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a40178380d2..344b75fb24b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -292,12 +292,16 @@ The following steps are needed to update the Chromium version.
 
 ### Bisecting upstream changes
 
-Sometimes, performing a Chromium roll causes tests to fail. To figure out the cause, you need to bisect Chromium revisions to figure out the earliest possible revision that changed the behavior. The script in `utils/bisect.js` can be helpful here. Given a Node.js script that calls `process.exit(1)` for bad revisions, run this from the Puppeteer repository’s root directory:
+Sometimes, performing a Chromium roll causes tests to fail. To figure out the cause, you need to bisect Chromium revisions to figure out the earliest possible revision that changed the behavior. The script in `utils/bisect.js` can be helpful here. Given a pattern for one or more unit tests, it will automatically bisect the current range:
 
 ```sh
 node utils/bisect.js --good 686378 --bad 706915 script.js
+
+node utils/bisect.js --unit-test Response.fromCache
 ```
 
+By default, it will use the Chromium revision in `src/revisions.ts` from the `main` branch and from the working tree to determine the range to bisect.
+
 ## Releasing to npm
 
 Releasing to npm consists of the following phases:
diff --git a/utils/bisect.js b/utils/bisect.js
index d81fdec8f59..60b7ba07c61 100755
--- a/utils/bisect.js
+++ b/utils/bisect.js
@@ -21,7 +21,7 @@ const pptr = require('..');
 const browserFetcher = pptr.createBrowserFetcher();
 const path = require('path');
 const fs = require('fs');
-const { fork } = require('child_process');
+const { fork, spawn, execSync } = require('child_process');
 
 const COLOR_RESET = '\x1b[0m';
 const COLOR_RED = '\x1b[31m';
@@ -35,12 +35,16 @@ Usage:
   node bisect.js --good <revision> --bad <revision> <script>
 
 Parameters:
-  --good    revision that is known to be GOOD
-  --bad     revision that is known to be BAD
-  <script>  path to the script that returns non-zero code for BAD revisions and 0 for good
+  --good       revision that is known to be GOOD, defaults to the chromium revision in src/revision.ts in the main branch 
+  --bad        revision that is known to be BAD, defaults to the chromium revision in src/revision.ts
+  --no-cache   do not keep downloaded Chromium revisions
+  --unit-test  pattern that identifies a unit tests that should be checked
+  --script     path to a script that returns non-zero code for BAD revisions and 0 for good
 
 Example:
-  node utils/bisect.js --good 577361 --bad 599821 simple.js
+  node utils/bisect.js --unit-test test
+  node utils/bisect.js --good 577361 --bad 599821 --script simple.js
+  node utils/bisect.js --good 577361 --bad 599821 --unit-test test
 `;
 
 if (argv.h || argv.help) {
@@ -49,23 +53,44 @@ if (argv.h || argv.help) {
 }
 
 if (typeof argv.good !== 'number') {
-  console.log(
-    COLOR_RED + 'ERROR: expected --good argument to be a number' + COLOR_RESET
-  );
-  console.log(help);
-  process.exit(1);
+  argv.good = getChromiumRevision('main');
+  if (typeof argv.good !== 'number') {
+    console.log(
+      COLOR_RED +
+        'ERROR: Could not parse current Chromium revision' +
+        COLOR_RESET
+    );
+    console.log(help);
+    process.exit(1);
+  }
 }
 
 if (typeof argv.bad !== 'number') {
+  argv.bad = getChromiumRevision();
+  if (typeof argv.bad !== 'number') {
+    console.log(
+      COLOR_RED +
+        'ERROR: Could not parse Chromium revision in the main branch' +
+        COLOR_RESET
+    );
+    console.log(help);
+    process.exit(1);
+  }
+}
+
+if (!argv.script && !argv['unit-test']) {
   console.log(
-    COLOR_RED + 'ERROR: expected --bad argument to be a number' + COLOR_RESET
+    COLOR_RED +
+      'ERROR: Expected to be given a script or a unit test to run' +
+      COLOR_RESET
   );
   console.log(help);
   process.exit(1);
 }
 
-const scriptPath = path.resolve(argv._[0]);
-if (!fs.existsSync(scriptPath)) {
+const scriptPath = argv.script ? path.resolve(argv.script) : null;
+
+if (argv.script && !fs.existsSync(scriptPath)) {
   console.log(
     COLOR_RED +
       'ERROR: Expected to be given a path to a script to run' +
@@ -75,7 +100,7 @@ if (!fs.existsSync(scriptPath)) {
   process.exit(1);
 }
 
-(async (scriptPath, good, bad) => {
+(async (scriptPath, good, bad, pattern, noCache) => {
   const span = Math.abs(good - bad);
   console.log(
     `Bisecting ${COLOR_YELLOW}${span}${COLOR_RESET} revisions in ${COLOR_YELLOW}~${
@@ -88,9 +113,11 @@ if (!fs.existsSync(scriptPath)) {
     const revision = await findDownloadableRevision(middle, good, bad);
     if (!revision || revision === good || revision === bad) break;
     let info = browserFetcher.revisionInfo(revision);
-    const shouldRemove = !info.local;
+    const shouldRemove = noCache && !info.local;
     info = await downloadRevision(revision);
-    const exitCode = await runScript(scriptPath, info);
+    const exitCode = await (pattern
+      ? runUnitTest(pattern, info)
+      : runScript(scriptPath, info));
     if (shouldRemove) await browserFetcher.remove(revision);
     let outcome;
     if (exitCode) {
@@ -124,7 +151,7 @@ if (!fs.existsSync(scriptPath)) {
   console.log(
     `RANGE: https://chromium.googlesource.com/chromium/src/+log/${fromSha}..${toSha}`
   );
-})(scriptPath, argv.good, argv.bad);
+})(scriptPath, argv.good, argv.bad, argv['unit-test'], argv['no-cache']);
 
 function runScript(scriptPath, revisionInfo) {
   const log = debug('bisect:runscript');
@@ -142,6 +169,23 @@ function runScript(scriptPath, revisionInfo) {
   });
 }
 
+function runUnitTest(pattern, revisionInfo) {
+  const log = debug('bisect:rununittest');
+  log('Running unit test');
+  const child = spawn('npm run unit', ['--', '-g', pattern], {
+    stdio: ['inherit', 'inherit', 'inherit', 'ipc'],
+    shell: true,
+    env: {
+      ...process.env,
+      PUPPETEER_EXECUTABLE_PATH: revisionInfo.executablePath,
+    },
+  });
+  return new Promise((resolve, reject) => {
+    child.on('error', (err) => reject(err));
+    child.on('exit', (code) => resolve(code));
+  });
+}
+
 async function downloadRevision(revision) {
   const log = debug('bisect:download');
   log(`Downloading ${revision}`);
@@ -227,3 +271,18 @@ function fetchJSON(url) {
     req.end();
   });
 }
+
+function getChromiumRevision(gitRevision = null) {
+  const fileName = 'src/revisions.ts';
+  const command = gitRevision
+    ? `git show ${gitRevision}:${fileName}`
+    : `cat ${fileName}`;
+  const result = execSync(command, {
+    encoding: 'utf8',
+    shell: true,
+  });
+
+  const m = result.match(/chromium: '(\d+)'/);
+  if (!m) return null;
+  return parseInt(m[1], 10);
+}