Merge branch 'master' into conditional-both-branch-relation

.devcontainer/Dockerfile

@@ -0,0 +1,7 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.154.0/containers/javascript-node/.devcontainer/base.Dockerfile
+
+# [Choice] Node.js version: 14, 12, 10
+ARG VARIANT="14-buster"
+FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:0-${VARIANT}
+
+RUN sudo -u node npm install -g gulp-cli

.devcontainer/devcontainer.json

@@ -0,0 +1,16 @@
+{
+    "name": "Node.js",
+    "build": {
+        "dockerfile": "Dockerfile",
+        "args": {
+            "VARIANT": "14"
+        }
+    },
+    "settings": {
+        "terminal.integrated.shell.linux": "/bin/bash"
+    },
+    "extensions": [
+        "dbaeumer.vscode-eslint"
+    ],
+    "remoteUser": "node"
+}

.dockerignore

@@ -43,7 +43,6 @@ yarn-error.log
 .parallelperf.*
 .failed-tests
 TEST-results.xml
-package-lock.json
 tests
 .vscode
 .git

.eslintrc.json

@@ -17,12 +17,27 @@
         "@typescript-eslint/adjacent-overload-signatures": "error",
         "@typescript-eslint/array-type": "error",
 
-        "camelcase": "off",
-        "@typescript-eslint/camelcase": ["error", { "properties": "never", "allow": ["^[A-Za-z][a-zA-Za-z]+_[A-Za-z]+$"] }],
+        "brace-style": "off",
+        "@typescript-eslint/brace-style": ["error", "stroustrup", { "allowSingleLine": true }],
+
+        "@typescript-eslint/naming-convention": [
+            "error",
+            { "selector": "typeLike", "format": ["PascalCase"], "filter": { "regex": "^(__String|[A-Za-z]+_[A-Za-z]+)$", "match": false } },
+            { "selector": "interface", "format": ["PascalCase"], "custom": { "regex": "^I[A-Z]", "match": false }, "filter": { "regex": "^I(Arguments|TextWriter|O([A-Z][a-z]+[A-Za-z]*)?)$", "match": false } },
+            { "selector": "variable", "format": ["camelCase", "PascalCase", "UPPER_CASE"], "leadingUnderscore": "allow", "filter": { "regex": "^(_{1,2}filename|_{1,2}dirname|_+|[A-Za-z]+_[A-Za-z]+)$", "match": false } },
+            { "selector": "function", "format": ["camelCase", "PascalCase"], "leadingUnderscore": "allow", "filter": { "regex": "^[A-Za-z]+_[A-Za-z]+$", "match": false } },
+            { "selector": "parameter", "format": ["camelCase"], "leadingUnderscore": "allow", "filter": { "regex": "^(_+|[A-Za-z]+_[A-Z][a-z]+)$", "match": false } },
+            { "selector": "method", "format": ["camelCase", "PascalCase"], "leadingUnderscore": "allow", "filter": { "regex": "^[A-Za-z]+_[A-Za-z]+$", "match": false } },
+            { "selector": "memberLike", "format": ["camelCase"], "leadingUnderscore": "allow", "filter": { "regex": "^[A-Za-z]+_[A-Za-z]+$", "match": false } },
+            { "selector": "enumMember", "format": ["camelCase", "PascalCase"], "leadingUnderscore": "allow", "filter": { "regex": "^[A-Za-z]+_[A-Za-z]+$", "match": false } },
+            { "selector": "property", "format": null }
+        ],
 
-        "@typescript-eslint/class-name-casing": "error",
         "@typescript-eslint/consistent-type-definitions": ["error", "interface"],
-        "@typescript-eslint/interface-name-prefix": "error",
+
+        "no-duplicate-imports": "off",
+        "@typescript-eslint/no-duplicate-imports": "error",
+
         "@typescript-eslint/no-inferrable-types": "error",
         "@typescript-eslint/no-misused-new": "error",
         "@typescript-eslint/no-this-alias": "error",
@@ -77,7 +92,6 @@
         "jsdoc/check-alignment": "error",
 
         // eslint
-        "brace-style": ["error", "stroustrup", { "allowSingleLine": true }],
         "constructor-super": "error",
         "curly": ["error", "multi-line"],
         "dot-notation": "error",
@@ -86,7 +100,6 @@
         "new-parens": "error",
         "no-caller": "error",
         "no-duplicate-case": "error",
-        "no-duplicate-imports": "error",
         "no-empty": "error",
         "no-eval": "error",
         "no-extra-bind": "error",

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -4,41 +4,70 @@ about: Create a report to help us improve TypeScript
 title: ''
 labels: ''
 assignees: ''
-
 ---
+# Bug Report
 
-<!-- 🚨 STOP 🚨 𝗦𝗧𝗢𝗣 🚨 𝑺𝑻𝑶𝑷 🚨
-
-Half of all issues filed here are duplicates, answered in the FAQ, or not appropriate for the bug tracker. Even if you think you've found a *bug*, please read the FAQ first, especially the Common "Bugs" That Aren't Bugs section!
+<!--
+  Please fill in each section completely. Thank you!
+-->
 
-Please help us by doing the following steps before logging an issue:
-  * Search: https://github.com/Microsoft/TypeScript/search?type=Issues
-  * Read the FAQ: https://github.com/Microsoft/TypeScript/wiki/FAQ
+### 🔎 Search Terms
 
-Please fill in the *entire* template below.
+<!--
+  What search terms did you use when trying to find an existing bug report?
+  List them here so people in the future can find this one more easily.
 -->
 
-<!--
-Please try to reproduce the issue with the latest published version. It may have already been fixed.
+### 🕗 Version & Regression Information
+
+<!-- When did you start seeing this bug occur?
+
+"Bugs" that have existed in TS for a long time are very likely to be FAQs; refer to
+  https://github.com/Microsoft/TypeScript/wiki/FAQ#common-bugs-that-arent-bugs
+
+If possible, please try testing the nightly version of TS to see if it's already been fixed.
 For npm: `typescript@next`
 This is also the 'Nightly' version in the playground: http://www.typescriptlang.org/play/?ts=Nightly
+
+Note: The TypeScript Playground can be used to try older versions of TypeScript.
+
+Please keep and fill in the line that best applies:
 -->
-**TypeScript Version:**  3.7.x-dev.201xxxxx
+- This is a crash
+- This changed between versions ______ and _______
+- This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
+- I was unable to test this on prior versions because _______
+
+### ⏯ Playground Link
 
-<!-- Search terms you tried before logging this (so others can find this issue more easily) -->
-**Search Terms:**
+<!--
+  A link to a TypeScript Playground "Share" link which shows this behavior
+
+  The TypeScript Workbench can be used for more complex setups, try
+  https://www.typescriptlang.org/dev/bug-workbench/
+
+  As a last resort, you can link to a repo, but these will be slower for us to investigate.
+-->
+[Playground link with relevant code](https://www.typescriptlang.org/play?#code/PTAEFkE9QYwewCYFNQHM5IM6gBZIE5JA)
 
-**Code**
+### 💻 Code
 
+<!-- Please post the relevant code sample here as well-->
 ```ts
-// A *self-contained* demonstration of the problem follows...
-// Test this by running `tsc` on the command-line, rather than through another build tool such as Gulp, Webpack, etc.
+// We can quickly address your report if:
+//  - The code sample is short. Nearly all TypeScript bugs can be demonstrated in 20-30 lines of code!
+//  - It doesn't use external libraries. These are often issues with the type definitions rather than TypeScript bugs.
+//  - The incorrectness of the behavior is readily apparent from reading the sample.
+// Reports are slower to investigate if:
+//  - We have to pare too much extraneous code.
+//  - We have to clone a large repo and validate that the problem isn't elsewhere.
+//  - The sample is confusing or doesn't clearly demonstrate what's wrong.
 ```
 
-**Expected behavior:**
+### 🙁 Actual behavior
 
-**Actual behavior:**
+<!-- What happened, and why it was wrong -->
 
-**Playground Link:** <!-- A link to a TypeScript Playground "Share" link which demonstrates this behavior -->
+### 🙂 Expected behavior
 
-**Related Issues:** <!-- Did you find other bugs that looked similar? -->
+<!-- What you expected to happen instead, and why -->

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -4,44 +4,56 @@ about: Suggest an idea
 title: ''
 labels: ''
 assignees: ''
-
 ---
+# Suggestion
 
-<!-- 🚨 STOP 🚨 𝗦𝗧𝗢𝗣 🚨 𝑺𝑻𝑶𝑷 🚨
-
-Half of all issues filed here are duplicates, answered in the FAQ, or not appropriate for the bug tracker.
-
-Please help us by doing the following steps before logging an issue:
-  * Search: https://github.com/Microsoft/TypeScript/search?type=Issues
-  * Read the FAQ, especially the "Common Feature Requests" section: https://github.com/Microsoft/TypeScript/wiki/FAQ
-
+<!--
+  Please fill in each section completely. Thank you!
 -->
 
-## Search Terms
+## 🔍 Search Terms
 
-<!-- List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily -->
+<!--
+  💡 Did you know? TypeScript has over 2,000 open suggestions!
+  🔎 Please search thoroughly before logging new feature requests as most common ideas already have a proposal in progress.
+  The "Common Feature Requests" section of the FAQ lists many popular requests: https://github.com/Microsoft/TypeScript/wiki/FAQ#common-feature-requests
 
-## Suggestion
+  Replace the text below:
+-->
 
-<!-- A summary of what you'd like to see added or changed -->
+List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily and help provide feedback.
 
-## Use Cases
+## ✅ Viability Checklist
 
 <!--
-What do you want to use this for?
-What shortcomings exist with current approaches?
+   Suggestions that don't meet all these criteria are very, very unlikely to be accepted.
+   We always recommend reviewing the TypeScript design goals before investing time writing
+   a proposal for ideas outside the scope of the project.
 -->
-
-## Examples
-
-<!-- Show how this would be used and what the behavior would be -->
-
-## Checklist
-
 My suggestion meets these guidelines:
 
 * [ ] This wouldn't be a breaking change in existing TypeScript/JavaScript code
 * [ ] This wouldn't change the runtime behavior of existing JavaScript code
 * [ ] This could be implemented without emitting different JS based on the types of the expressions
-* [ ] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
+* [ ] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
 * [ ] This feature would agree with the rest of [TypeScript's Design Goals](https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals).
+
+
+## ⭐ Suggestion
+
+<!-- A summary of what you'd like to see added or changed -->
+
+## 📃 Motivating Example
+
+<!--
+  If you were announcing this feature in a blog post, what's a short explanation that shows
+  a developer why this feature improves the language?
+-->
+
+## 💻 Use Cases
+
+<!--
+  What do you want to use this for?
+  What shortcomings exist with current approaches?
+  What workarounds are you using in the meantime?
+-->

.github/ISSUE_TEMPLATE/config.yml

@@ -14,6 +14,6 @@ contact_links:
     name: "TypeScript FAQ"
     url: "https://github.com/microsoft/TypeScript/wiki/FAQ"
   - 
-    about: "Please raise issues about the site on it's own repo."
+    about: "Please raise issues about the site on its own repo."
     name: Website
     url: "https://github.com/microsoft/TypeScript-Website/issues/new"

.github/ISSUE_TEMPLATE/lib_change.md

@@ -0,0 +1,55 @@
+---
+name: Library change
+about: Fix or improve issues with built-in type definitions like `lib.dom.d.ts`, `lib.es6.d.ts`, etc.
+title: ''
+labels: ''
+assignees: ''
+---
+# lib Update Request
+
+<!--
+  Please fill in each section completely. Thank you!
+
+  Are you here for one of these commonly-requested lib changes?
+    * Object.keys - see https://stackoverflow.com/questions/55012174/
+    * Array methods - see https://github.com/microsoft/TypeScript/issues/36554
+    * parseInt, parseFloat, isFinite, isNaN, etc. - see https://github.com/microsoft/TypeScript/issues/4002
+
+  The DOM lib is maintained elsewhere and you can skip a step by filing issues/PRs for the DOM at that repo.
+  See https://github.com/microsoft/TypeScript-DOM-lib-generator
+-->
+
+## Configuration Check
+
+<!--
+  If you're missing common new methods like Array.includes, you may have a misconfigured project.
+  Try setting `lib: "es2020"` and checking whether the type you want is present.
+  You can diagnose further by running `tsc` with `--listFilesOnly` or `--showConfig`.
+
+  Conversely, if you are seeing built-in methods you expect to *not* see, check your 'lib' setting
+  or review your dependencies for lib/reference directives that might be polluting
+  your global scope. This is common when using the 'node' type library. See https://github.com/microsoft/TypeScript/issues/40184
+
+  Replace the text below:
+-->
+My compilation *target* is `ES2015` and my *lib* is `the default`.
+
+## Missing / Incorrect Definition
+
+<!--
+  What property, method, function, etc is missing or incorrect?
+-->
+
+## Sample Code
+
+<!--
+  What's some code using this that should work, but doesn't?
+-->
+
+## Documentation Link
+
+<!--
+  Link to relevant documentation (e.g. MDN, W3C, ECMAScript Spec) to consult for this property.
+  Note that lib.dom.d.ts intentionally does not include browser-specific extensions
+   or early experimental features.
+-->

.github/codeql/codeql-configuration.yml

@@ -0,0 +1,4 @@
+name : CodeQL Configuration
+
+paths:
+  - './src' 

.github/pr_owners.txt

@@ -6,3 +6,8 @@ RyanCavanaugh
 sheetalkamat
 orta
 rbuckton
+ahejlsberg
+amcasey
+jessetrinity
+minestarks
+uniqueiniquity

.github/tsc.json

@@ -0,0 +1,18 @@
+{
+  "problemMatcher": [
+      {
+          "owner": "tsc",
+          "pattern": [
+              {
+                  "regexp": "^(?:\\s+\\d+\\>)?([^\\s].*)\\((\\d+),(\\d+)\\)\\s*:\\s+(error|warning|info)\\s+(\\w{1,2}\\d+)\\s*:\\s*(.*)$",
+                  "file": 1,
+                  "line": 2,
+                  "column": 3,
+                  "severity": 4,
+                  "code": 5,
+                  "message": 6
+              }
+          ]
+      }
+  ]
+}

.github/workflows/accept-baselines-fix-lints.yaml

@@ -0,0 +1,29 @@
+name: Accept Baselines and Fix Lints
+
+on:
+  workflow_dispatch: {}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use node version 12
+      uses: actions/setup-node@v1
+      with:
+        node-version: 12
+        registry-url: https://registry.npmjs.org/
+
+    - name: Configure Git, Run Tests, Update Baselines, Apply Fixes
+      run: |
+        git config user.email "[email protected]"
+        git config user.name "TypeScript Bot"
+        npm install
+        gulp runtests-parallel --ci --fix || true
+        gulp baseline-accept
+        git add ./src
+        git add ./tests/baselines/reference
+        git diff --cached
+        git commit -m "Update Baselines and/or Applied Lint Fixes"
+        git push