Adds a patchfile for fsevents (yarnpkg#692)

* Adds a patchfile for fsevents

* Fix & debug

* Removes old-style from the tests

* Increases the timeout on CI?

* Refactors the test

* Removes snapshot

* Escapes heredoc

* Adds the release file

* No backticks allowed in Bash

* Checks whether the problem comes from the patch or native

* Skips fsevents@1 and goes to latest

* Calls the watch fn

* Fixes the 2.x patch

* Adds the CI tests to the README

* Updates FSEvents

* Fixes the patch

* Fixes the checked-in artifacts

.editorconfig

@@ -14,3 +14,7 @@ indent_size = 2
 [*.md]
 # trailing whitespace is significant in markdown -> do not remove
 trim_trailing_whitespace = false
+
+[*.patch]
+trim_trailing_whitespace = false
+insert_final_newline = false

.github/workflows/e2e-fsevents-workflow.yml

@@ -0,0 +1,160 @@
+on:
+  schedule:
+  - cron: '0 */4 * * *'
+  push:
+    branches:
+    - master
+  pull_request:
+    paths:
+    - .github/workflows/e2e-fsevents-workflow.yml
+    - scripts/e2e-setup-ci.sh
+
+name: 'E2E FSEvents'
+jobs:
+  chore:
+    name: 'Validating FSEvents'
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@master
+
+    - name: 'Use Node.js 10.x'
+      uses: actions/setup-node@master
+      with:
+        node-version: 10.x
+
+    - name: 'Build the standard bundle'
+      run: |
+        node ./scripts/run-yarn.js build:cli
+
+    - name: 'Running the integration test (FSEvents ^1)'
+      run: |
+        source scripts/e2e-setup-ci.sh
+        yarn init
+        yarn add fsevents@^1
+
+        cat > test.js <<EOT
+          const assert = require('assert');
+          const fsevents = require('fsevents');
+          const fs = require('fs');
+          const path = require('path');
+
+          async function sleep(n) {
+            return new Promise(resolve => {
+              setTimeout(resolve, n);
+            });
+          }
+
+          async function runTestOn(dir, fileName) {
+            const file = path.join(dir, fileName);
+
+            const events = [];
+            const watcher = fsevents(dir);
+            watcher.on('change', (...args) => events.push(args));
+            watcher.start();
+
+            async function main() {
+              await sleep(1000);
+              fs.writeFileSync(file, '');
+              await sleep(1000);
+
+              if (events.length === 0)
+                throw new Error('No events recorded');
+
+              for (const [p] of events) {
+                if (!p.startsWith(dir)) {
+                  throw new Error(p);
+                }
+              }
+            }
+
+            try {
+              return await main();
+            } finally {
+              watcher.stop();
+            }
+          }
+
+          async function registerTest(dir, fileName) {
+            try {
+              await runTestOn(dir, fileName);
+              console.log('Succeeded test for ' + dir);
+            } catch (error) {
+              console.log('Failed test for ' + dir + ': ' + error.message);
+              process.exitCode = 1;
+            }
+          }
+
+          Promise.resolve().then(() => {
+            return registerTest(process.cwd(), 'hello');
+          }).then(() => {
+            return registerTest(process.cwd() + '/\$\$virtual/foo/0', 'world');
+          });
+        EOT
+
+        yarn node ./test.js
+
+    - name: 'Running the integration test (FSEvents latest)'
+      run: |
+        source scripts/e2e-setup-ci.sh
+        yarn init
+        yarn add fsevents@latest
+
+        cat > test.js <<EOT
+          const assert = require('assert');
+          const fsevents = require('fsevents');
+          const fs = require('fs');
+          const path = require('path');
+
+          async function sleep(n) {
+            return new Promise(resolve => {
+              setTimeout(resolve, n);
+            });
+          }
+
+          async function runTestOn(dir, fileName) {
+            const file = path.join(dir, fileName);
+
+            const events = [];
+            const stop = fsevents.watch(dir, (...args) => events.push(args));
+
+            async function main() {
+              await sleep(1000);
+              fs.writeFileSync(file, '');
+              await sleep(1000);
+
+              if (events.length === 0)
+                throw new Error('No events recorded');
+
+              for (const [p] of events) {
+                if (!p.startsWith(dir)) {
+                  throw new Error(p);
+                }
+              }
+            }
+
+            try {
+              return await main();
+            } finally {
+              await stop();
+            }
+          }
+
+          async function registerTest(dir, fileName) {
+            try {
+              await runTestOn(dir, fileName);
+              console.log('Succeeded test for ' + dir);
+            } catch (error) {
+              console.log('Failed test for ' + dir + ': ' + error.message);
+              process.exitCode = 1;
+            }
+          }
+
+          Promise.resolve().then(() => {
+            return registerTest(process.cwd(), 'hello');
+          }).then(() => {
+            return registerTest(process.cwd() + '/\$\$virtual/foo/0', 'world');
+          });
+        EOT
+
+        yarn node ./test.js

.yarn/versions/d732ee1c.yml

@@ -0,0 +1,20 @@
+releases:
+  "@yarnpkg/[email protected]": prerelease
+  "@yarnpkg/[email protected]": prerelease
+  "@yarnpkg/[email protected]": prerelease
+
+declined:
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"
+  - "@yarnpkg/[email protected]"

README.md

@@ -50,6 +50,7 @@ On top of our classic integration tests, we also run Yarn every day against the
 </td><td valign="top">
 
 [![](https://github.com/yarnpkg/berry/workflows/E2E%20ESLint/badge.svg?event=schedule)](https://github.com/yarnpkg/berry/blob/master/.github/workflows/e2e-eslint-workflow.yml)<br/>
+[![](https://github.com/yarnpkg/berry/workflows/E2E%20FSEvents/badge.svg?event=schedule)](https://github.com/yarnpkg/berry/blob/master/.github/workflows/e2e-fsevents-workflow.yml)<br/>
 [![](https://github.com/yarnpkg/berry/workflows/E2E%20Husky/badge.svg?event=schedule)](https://github.com/yarnpkg/berry/blob/master/.github/workflows/e2e-husky-workflow.yml)<br/>
 [![](https://github.com/yarnpkg/berry/workflows/E2E%20Jest/badge.svg?event=schedule)](https://github.com/yarnpkg/berry/blob/master/.github/workflows/e2e-jest-workflow.yml)<br/>
 [![](https://github.com/yarnpkg/berry/workflows/E2E%20Mocha/badge.svg?event=schedule)](https://github.com/yarnpkg/berry/blob/master/.github/workflows/e2e-mocha-workflow.yml)<br/>

packages/plugin-compat/extra/fsevents/1.2.11.patch

@@ -0,0 +1,21 @@
+diff --git a/fsevents.js b/fsevents.js
+semver exclusivity ^1
+--- a/fsevents.js
++++ b/fsevents.js
+@@ -36,11 +36,15 @@ module.exports.Constants = Native.Constants;
+ var defer = global.setImmediate || process.nextTick;
+
+ function watch(path) {
+-  var fse = new FSEvents(String(path || ''), handler);
++  var VFS = require('./vfs');
++  var vfs = new VFS(String(path || ''));
++
++  var fse = new FSEvents(vfs.resolvedPath, handler);
+   EventEmitter.call(fse);
+   return fse;
+
+   function handler(path, flags, id) {
++    path = vfs.transpose(path);
+     defer(function() {
+       fse.emit('fsevent', path, flags, id);
+       var info = getInfo(path, flags);

packages/plugin-compat/extra/fsevents/2.1.2.patch

@@ -0,0 +1,13 @@
+diff --git a/fsevents.js b/fsevents.js
+semver exclusivity ^2
+--- a/fsevents.js
++++ b/fsevents.js
+@@ -21,5 +21,7 @@ function watch(path, handler) {
+     throw new TypeError(`fsevents argument 2 must be a function and not a ${typeof handler}`);
+   }
+
+-  let instance = Native.start(path, handler);
++  let VFS = require('./vfs');
++  let vfs = new VFS(path);
++  let instance = Native.start(vfs.resolvedPath, vfs.wrap(handler));
+   if (!instance) throw new Error(`could not watch: ${path}`);

packages/plugin-compat/extra/fsevents/common.patch

@@ -0,0 +1,46 @@
+diff --git a/vfs.js b/vfs.js
+new file mode 100644
+--- /dev/null
++++ b/vfs.js
+@@ -0,0 +1,41 @@
++const path = require(`path`);
++
++const NUMBER_REGEXP = /^[0-9]+$/;
++const VIRTUAL_REGEXP = /^(\/(?:[^\/]+\/)*?\$\$virtual)((?:\/([^\/]+)(?:\/([^\/]+))?)?((?:\/.*)?))$/;
++
++function resolveVirtual(p) {
++  const match = p.match(VIRTUAL_REGEXP);
++  if (!match)
++    return p;
++
++  const target = path.dirname(match[1]);
++  if (!match[3] || !match[4])
++    return target;
++
++  const isnum = NUMBER_REGEXP.test(match[4]);
++  if (!isnum)
++    return p;
++
++  const depth = Number(match[4]);
++  const backstep = `../`.repeat(depth);
++  const subpath = (match[5] || `.`);
++
++  return resolveVirtual(path.join(target, backstep, subpath));
++}
++
++module.exports = class FsePnp {
++  constructor(p) {
++    this.normalizedPath = path.resolve(p);
++    this.resolvedPath = resolveVirtual(this.normalizedPath);
++  }
++
++  transpose(p) {
++    return this.normalizedPath + p.substr(this.resolvedPath.length);
++  }
++
++  wrap(fn) {
++    return (path, ...args) => {
++      return fn(this.transpose(path), ...args);
++    };
++  }
++};

packages/plugin-compat/extra/fsevents/gen-fsevents-patch.sh

@@ -0,0 +1,20 @@
+set -ex
+
+THIS_DIR=$(cd -P "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+TEMP_DIR="$(mktemp -d)"
+
+echo $TEMP_DIR
+
+PATCHFILE="$THIS_DIR"/../../sources/patches/fsevents.patch.ts
+rm -f "$PATCHFILE" && touch "$PATCHFILE"
+
+echo 'export const patch =' \
+  >> "$PATCHFILE"
+(cat "$THIS_DIR"/1.2.11.patch \
+     "$THIS_DIR"/2.1.2.patch \
+     "$THIS_DIR"/common.patch) \
+  > "$TEMP_DIR"/patch.tmp || true
+node "$THIS_DIR"/../jsonEscape.js < "$TEMP_DIR"/patch.tmp \
+  >> "$PATCHFILE"
+echo ';' \
+  >> "$PATCHFILE"

packages/plugin-compat/sources/index.ts

@@ -1,10 +1,12 @@
 import {Hooks as CoreHooks, Plugin, structUtils} from '@yarnpkg/core';
 import {Hooks as PatchHooks}                     from '@yarnpkg/plugin-patch';
 
+import {patch as fseventsPatch}                  from './patches/fsevents.patch';
 import {patch as resolvePatch}                   from './patches/resolve.patch';
 import {patch as typescriptPatch}                from './patches/typescript.patch';
 
 const PATCHES = new Map([
+  [structUtils.makeIdent(null, `fsevents`).identHash, fseventsPatch],
   [structUtils.makeIdent(null, `resolve`).identHash, resolvePatch],
   [structUtils.makeIdent(null, `typescript`).identHash, typescriptPatch],
 ]);

packages/plugin-compat/sources/patches/fsevents.patch.ts

@@ -0,0 +1,3 @@
+export const patch =
+"diff --git a/fsevents.js b/fsevents.js\nsemver exclusivity ^1\n--- a/fsevents.js\n+++ b/fsevents.js\n@@ -36,11 +36,15 @@ module.exports.Constants = Native.Constants;\n var defer = global.setImmediate || process.nextTick;\n\n function watch(path) {\n-  var fse = new FSEvents(String(path || ''), handler);\n+  var VFS = require('./vfs');\n+  var vfs = new VFS(String(path || ''));\n+\n+  var fse = new FSEvents(vfs.resolvedPath, handler);\n   EventEmitter.call(fse);\n   return fse;\n\n   function handler(path, flags, id) {\n+    path = vfs.transpose(path);\n     defer(function() {\n       fse.emit('fsevent', path, flags, id);\n       var info = getInfo(path, flags);\ndiff --git a/fsevents.js b/fsevents.js\nsemver exclusivity ^2\n--- a/fsevents.js\n+++ b/fsevents.js\n@@ -21,5 +21,7 @@ function watch(path, handler) {\n     throw new TypeError(`fsevents argument 2 must be a function and not a ${typeof handler}`);\n   }\n\n-  let instance = Native.start(path, handler);\n+  let VFS = require('./vfs');\n+  let vfs = new VFS(path);\n+  let instance = Native.start(vfs.resolvedPath, vfs.wrap(handler));\n   if (!instance) throw new Error(`could not watch: ${path}`);\ndiff --git a/vfs.js b/vfs.js\nnew file mode 100644\n--- /dev/null\n+++ b/vfs.js\n@@ -0,0 +1,41 @@\n+const path = require(`path`);\n+\n+const NUMBER_REGEXP = /^[0-9]+$/;\n+const VIRTUAL_REGEXP = /^(\\/(?:[^\\/]+\\/)*?\\$\\$virtual)((?:\\/([^\\/]+)(?:\\/([^\\/]+))?)?((?:\\/.*)?))$/;\n+\n+function resolveVirtual(p) {\n+  const match = p.match(VIRTUAL_REGEXP);\n+  if (!match)\n+    return p;\n+\n+  const target = path.dirname(match[1]);\n+  if (!match[3] || !match[4])\n+    return target;\n+\n+  const isnum = NUMBER_REGEXP.test(match[4]);\n+  if (!isnum)\n+    return p;\n+\n+  const depth = Number(match[4]);\n+  const backstep = `../`.repeat(depth);\n+  const subpath = (match[5] || `.`);\n+\n+  return resolveVirtual(path.join(target, backstep, subpath));\n+}\n+\n+module.exports = class FsePnp {\n+  constructor(p) {\n+    this.normalizedPath = path.resolve(p);\n+    this.resolvedPath = resolveVirtual(this.normalizedPath);\n+  }\n+\n+  transpose(p) {\n+    return this.normalizedPath + p.substr(this.resolvedPath.length);\n+  }\n+\n+  wrap(fn) {\n+    return (path, ...args) => {\n+      return fn(this.transpose(path), ...args);\n+    };\n+  }\n+};\n"
+;