fs: add option parents to

    - fs.open[Sync],
    - fs.writeFile[Sync],
    - fs.appendFile[Sync]

this feature is intended to improve ergonomics/simplify-scripting when:
- creating build-artifacts/coverage-files during ci
- scaffolding new web-projects
- cloning website with web-crawler

allowing user to lazily create ad-hoc directory-structures as need
during file-creation with ergonomic syntax:
```
fs.writeFileSync(
    "foo/bar/baz/qux.txt",
    "hello world!",
    { parents: true } // will lazily create parent foo/bar/baz/ as needed
);
```

fs: add new signature-form fs.open(path[, options], callback)
fs: add new signature-form fs.openSync(path[, options])

Fixes: #33559

.eslintignore

@@ -1,5 +1,4 @@
 node_modules
-lib/internal/v8_prof_polyfill.js
 lib/punycode.js
 test/addons/??_*
 test/fixtures

.eslintrc.js

@@ -16,7 +16,8 @@ const ModuleFindPath = Module._findPath;
 const hacks = [
   'eslint-plugin-node-core',
   'eslint-plugin-markdown',
-  'babel-eslint',
+  '@babel/eslint-parser',
+  '@babel/plugin-syntax-class-properties',
 ];
 Module._findPath = (request, paths, isMain) => {
   const r = ModuleFindPath(request, paths, isMain);
@@ -37,8 +38,14 @@ Module._findPath = (request, paths, isMain) => {
 module.exports = {
   root: true,
   plugins: ['markdown', 'node-core'],
-  parser: 'babel-eslint',
-  parserOptions: { sourceType: 'script' },
+  parser: '@babel/eslint-parser',
+  parserOptions: {
+    babelOptions: {
+      plugins: [Module._findPath('@babel/plugin-syntax-class-properties')],
+    },
+    requireConfigFile: false,
+    sourceType: 'script',
+  },
   overrides: [
     {
       files: [
@@ -150,6 +157,7 @@ module.exports = {
     'no-multiple-empty-lines': ['error', { max: 2, maxEOF: 0, maxBOF: 0 }],
     'no-new-require': 'error',
     'no-new-symbol': 'error',
+    'no-nonoctal-decimal-escape': 'error',
     'no-obj-calls': 'error',
     'no-octal': 'error',
     'no-path-concat': 'error',
@@ -226,6 +234,8 @@ module.exports = {
     'no-unreachable': 'error',
     'no-unsafe-finally': 'error',
     'no-unsafe-negation': 'error',
+    'no-unsafe-optional-chaining': 'error',
+    'no-unused-expressions': ['error', { allowShortCircuit: true }],
     'no-unused-labels': 'error',
     'no-unused-vars': ['error', { args: 'none', caughtErrors: 'all' }],
     'no-use-before-define': ['error', {

.github/ISSUE_TEMPLATE/1-bug-report.md

@@ -15,7 +15,7 @@ repo. https://github.com/nodejs/help
 Please fill in as much of the template below as you're able.
 
 Version: output of `node -v`
-Platform: output of `uname -a` (UNIX), or version and 32 or 64-bit (Windows)
+Platform: output of `uname -a` (UNIX), or output of `"$([Environment]::OSVersion | ForEach-Object VersionString) $(if ([Environment]::Is64BitOperatingSystem) { "x64" } else { "x86" })"` in PowerShell console (Windows)
 Subsystem: if known, please specify affected core module name
 -->
 

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,21 +1,15 @@
 <!--
-Thank you for your pull request. Please provide a description above and review
-the requirements below.
+Before submitting a pull request, please read
+https://github.com/nodejs/node/blob/master/CONTRIBUTING.md.
 
-Bug fixes and new features should include tests and possibly benchmarks.
+Commit message formatting guidelines:
+https://github.com/nodejs/node/blob/master/doc/guides/contributing/pull-requests.md#commit-message-guidelines
 
-Contributors guide: https://github.com/nodejs/node/blob/master/CONTRIBUTING.md
--->
-
-##### Checklist
-<!-- Remove items that do not apply. For completed items, change [ ] to [x]. -->
+For code changes:
+1. Include tests for any bug fixes or new features.
+2. Update documentation if relevant.
+3. Ensure that `make -j4 test` (UNIX), or `vcbuild test` (Windows) passes.
 
-- [ ] `make -j4 test` (UNIX), or `vcbuild test` (Windows) passes
-- [ ] tests and/or benchmarks are included
-- [ ] documentation is changed or added
-- [ ] commit message follows [commit guidelines](https://github.com/nodejs/node/blob/master/doc/guides/contributing/pull-requests.md#commit-message-guidelines)
-
-<!--
 Developer's Certificate of Origin 1.1
 
 By making a contribution to this project, I certify that:

.github/workflows/build-tarball.yml

@@ -13,6 +13,7 @@ env:
 
 jobs:
   build-tarball:
+    if: github.event.pull_request.draft == false
     env:
       PYTHON_VERSION: 3.9
     runs-on: ubuntu-latest

.github/workflows/build-windows.yml

@@ -15,6 +15,7 @@ env:
 
 jobs:
   build-windows-with-quic:
+    if: github.event.pull_request.draft == false
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/close-stalled.yml

@@ -5,6 +5,7 @@ on:
 
 jobs:
   stale:
+    if: github.repository == 'nodejs/node'
     runs-on: ubuntu-latest
     steps:
     - uses: actions/stale@v3

.github/workflows/comment-stalled.yml

@@ -7,6 +7,7 @@ on:
 
 jobs:
   staleComment:
+    if: github.repository == 'nodejs/node'
     runs-on: ubuntu-latest
     steps:
       - name: Post comment

.github/workflows/coverage-linux.yml

@@ -22,6 +22,7 @@ env:
 
 jobs:
   coverage-linux:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/coverage-windows.yml

@@ -22,6 +22,7 @@ env:
 
 jobs:
   coverage-windows:
+    if: github.event.pull_request.draft == false
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/license-builder.yml

@@ -7,7 +7,8 @@ on:
   workflow_dispatch:
 
 jobs:
-  update_routes:
+  update_license:
+    if: github.repository == 'nodejs/node'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/linters.yml

@@ -14,6 +14,7 @@ env:
 
 jobs:
   lint-addon-docs:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -24,8 +25,9 @@ jobs:
       - name: Environment Information
         run: npx envinfo
       - name: Lint addon docs
-        run: NODE=$(which node) make lint-addon-docs
+        run: NODE=$(command -v node) make lint-addon-docs
   lint-cpp:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -38,6 +40,7 @@ jobs:
       - name: Lint C/C++ files
         run: make lint-cpp
   lint-md:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -50,8 +53,9 @@ jobs:
       - name: Lint docs
         run: |
           echo "::add-matcher::.github/workflows/remark-lint-problem-matcher.json"
-          NODE=$(which node) make lint-md
+          NODE=$(command -v node) make lint-md
   lint-js:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -62,8 +66,9 @@ jobs:
       - name: Environment Information
         run: npx envinfo
       - name: Lint JavaScript files
-        run: NODE=$(which node) make lint-js
+        run: NODE=$(command -v node) make lint-js
   lint-py:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -76,9 +81,17 @@ jobs:
       - name: Lint Python
         run: |
           make lint-py-build || true
-          NODE=$(which node) make lint-py
-
+          NODE=$(command -v node) make lint-py
+  lint-sh:
+    if: github.event.pull_request.draft == false
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - run: shellcheck -V
+      - name: Lint Shell scripts
+        run: tools/lint-sh.js .
   lint-codeowners:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/misc.yml

@@ -13,6 +13,7 @@ env:
 
 jobs:
   build-docs:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -23,7 +24,7 @@ jobs:
       - name: Environment Information
         run: npx envinfo
       - name: Build
-        run: NODE=$(which node) make doc-only
+        run: NODE=$(command -v node) make doc-only
       - uses: actions/upload-artifact@v1
         with:
           name: docs

.github/workflows/notify-force-push.yml

@@ -0,0 +1,25 @@
+on:
+  push:
+    branches:
+      - master
+
+name: Notify on Force Push
+jobs:
+  slackNotification:
+    name: Slack Notification
+    if: ${{ github.event.forced && github.repository == 'nodejs/node' }}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Slack Notification
+      uses: rtCamp/action-slack-notify@master
+      env:
+        SLACK_COLOR: '#DE512A'
+        SLACK_ICON: https://github.com/nodejs.png?size=48
+        SLACK_TITLE: '${{ github.actor }} force-pushed to ${{ github.ref }}'
+        SLACK_MESSAGE: |
+          A commit was force-pushed to <https://github.com/${{ github.repository }}/tree/master|${{ github.repository }}@master> by <https://github.com/${{ github.actor }}|${{ github.actor }}>
+
+          Before: <https://github.com/${{ github.repository }}/commit/${{ github.event.before }}|${{ github.event.before }}>
+          After: <https://github.com/${{ github.repository }}/commit/${{ github.event.after }}|${{ github.event.after }}>
+        SLACK_USERNAME: nodejs-bot
+        SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK }}

.github/workflows/test-asan.yml

@@ -19,6 +19,7 @@ env:
 
 jobs:
   test-asan:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     env:
       CC: clang

.github/workflows/test-linux.yml

@@ -15,6 +15,7 @@ env:
 
 jobs:
   test-linux:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -30,6 +31,7 @@ jobs:
         run: make run-ci -j2 V=1 TEST_CI_ARGS="-p actions"
 
   test-linux-with-quic:
+    if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/test-macos.yml

@@ -15,6 +15,7 @@ env:
 
 jobs:
   test-macOS-with-quic:
+    if: github.event.pull_request.draft == false
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v2
@@ -25,6 +26,6 @@ jobs:
       - name: Environment Information
         run: npx envinfo
       - name: Build
-        run: make build-ci -j8 V=1 CONFIG_FLAGS="--error-on-warn --experimental-quic"
+        run: make build-ci -j2 V=1 CONFIG_FLAGS="--error-on-warn --experimental-quic"
       - name: Test
-        run: make run-ci -j8 V=1 TEST_CI_ARGS="-p actions"
+        run: make run-ci -j2 V=1 TEST_CI_ARGS="-p actions"

BSDmakefile

@@ -3,7 +3,7 @@ FLAGS=${.MAKEFLAGS:C/\-J ([0-9]+,?)+//W}
 
 all: .DEFAULT
 .DEFAULT:
-	@which gmake > /dev/null 2>&1 ||\
+	@command -v gmake > /dev/null 2>&1 ||\
 		(echo "GMake is required for node.js to build.\
 			Install and try again" && exit 1)
 	@gmake ${.FLAGS} ${.TARGETS}

BUILDING.md

@@ -30,6 +30,7 @@ file a new issue.
     * [Building the documentation](#building-the-documentation)
     * [Building a debug build](#building-a-debug-build)
     * [Building an ASAN build](#building-an-asan-build)
+    * [Speeding up frequent rebuilds when developing](#speeding-up-frequent-rebuilds-when-developing)
     * [Troubleshooting Unix and macOS builds](#troubleshooting-unix-and-macos-builds)
   * [Windows](#windows)
     * [Prerequisites](#prerequisites)
@@ -113,6 +114,7 @@ platforms. This is true regardless of entries in the table below.
 | Windows          | x64, x86         | Windows Server 2012 (not R2)    | Experimental |                                   |
 | Windows          | arm64            | >= Windows 10                   | Tier 2 (compiling) / Experimental (running) |    |
 | macOS            | x64              | >= 10.13                        | Tier 1       |                                   |
+| macOS            | arm64            | >= 11                           | Experimental |                                   |
 | SmartOS          | x64              | >= 18                           | Tier 2       |                                   |
 | AIX              | ppc64be >=power7 | >= 7.2 TL02                     | Tier 2       |                                   |
 | FreeBSD          | x64              | >= 11                           | Experimental | Downgraded as of Node.js 12  <sup>[7](#fn7)</sup>     |
@@ -526,6 +528,29 @@ $  ./configure --debug --enable-asan && make -j4
 $ make test-only
 ```
 
+#### Speeding up frequent rebuilds when developing
+
+If you plan to frequently rebuild Node.js, especially if using several branches,
+installing `ccache` can help to greatly reduce build times. Set up with:
+```console
+$ sudo apt install ccache   # for Debian/Ubuntu, included in most Linux distros
+$ ccache -o cache_dir=<tmp_dir>
+$ ccache -o max_size=5.0G
+$ export CC="ccache gcc"    # add to your .profile
+$ export CXX="ccache g++"   # add to your .profile
+```
+This will allow for near-instantaneous rebuilds even when switching branches.
+
+When modifying only the JS layer in `lib`, it is possible to externally load it
+without modifying the executable:
+```console
+$ ./configure --node-builtin-modules-path $(pwd)
+```
+The resulting binary won't include any JS files and will try to load them from
+the specified directory. The JS debugger of Visual Studio Code supports this
+configuration since the November 2020 version and allows for setting
+breakpoints.
+
 #### Troubleshooting Unix and macOS builds
 
 Stale builds can sometimes result in `file not found` errors while building.

CHANGELOG.md

@@ -32,14 +32,21 @@ release.
 </tr>
 <tr>
     <td valign="top">
-<b><a href="doc/changelogs/CHANGELOG_V15.md#15.2.1">15.2.1</a></b><br/>
+<b><a href="doc/changelogs/CHANGELOG_V15.md#15.5.1">15.5.1</a></b><br/>
+<a href="doc/changelogs/CHANGELOG_V15.md#15.5.0">15.5.0</a><br/>
+<a href="doc/changelogs/CHANGELOG_V15.md#15.4.0">15.4.0</a><br/>
+<a href="doc/changelogs/CHANGELOG_V15.md#15.3.0">15.3.0</a><br/>
+<a href="doc/changelogs/CHANGELOG_V15.md#15.2.1">15.2.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V15.md#15.2.0">15.2.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V15.md#15.1.0">15.1.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V15.md#15.0.1">15.0.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V15.md#15.0.0">15.0.0</a><br/>
     </td>
     <td valign="top">
-<b><a href="doc/changelogs/CHANGELOG_V14.md#14.15.1">14.15.1</a></b><br/>
+<b><a href="doc/changelogs/CHANGELOG_V14.md#14.15.4">14.15.4</a></b><br/>
+<a href="doc/changelogs/CHANGELOG_V14.md#14.15.3">14.15.3</a><br/>
+<a href="doc/changelogs/CHANGELOG_V14.md#14.15.2">14.15.2</a><br/>
+<a href="doc/changelogs/CHANGELOG_V14.md#14.15.1">14.15.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V14.md#14.15.0">14.15.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V14.md#14.14.0">14.14.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V14.md#14.13.1">14.13.1</a><br/>
@@ -60,7 +67,9 @@ release.
 <a href="doc/changelogs/CHANGELOG_V14.md#14.0.0">14.0.0</a><br/>
     </td>
     <td valign="top">
-<b><a href="doc/changelogs/CHANGELOG_V12.md#12.19.1">12.19.1</a></b><br/>
+<b><a href="doc/changelogs/CHANGELOG_V12.md#12.20.1">12.20.1</a></b><br/>
+<a href="doc/changelogs/CHANGELOG_V12.md#12.20.0">12.20.0</a><br/>
+<a href="doc/changelogs/CHANGELOG_V12.md#12.19.1">12.19.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V12.md#12.19.0">12.19.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V12.md#12.18.4">12.18.4</a><br/>
 <a href="doc/changelogs/CHANGELOG_V12.md#12.18.3">12.18.3</a><br/>
@@ -96,7 +105,8 @@ release.
 <a href="doc/changelogs/CHANGELOG_V12.md#12.0.0">12.0.0</a><br/>
     </td>
     <td valign="top">
-<b><a href="doc/changelogs/CHANGELOG_V10.md#10.23.0">10.23.0</a></b><br/>
+<b><a href="doc/changelogs/CHANGELOG_V10.md#10.23.1">10.23.1</a></b><br/>
+<a href="doc/changelogs/CHANGELOG_V10.md#10.23.0">10.23.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V10.md#10.22.1">10.22.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V10.md#10.22.0">10.22.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V10.md#10.21.0">10.21.0</a><br/>