Merge remote-tracking branch 'mine/extract-symbol-this' into extract-symbol-this

Author: Zzzen

.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 +1,22 @@
+{
+    "name": "Node.js",
+    "build": {
+        "dockerfile": "Dockerfile",
+        "args": {
+            "VARIANT": "14"
+        }
+    },
+    "settings": {
+        "terminal.integrated.defaultProfile.linux": "bash",
+        "terminal.integrated.profiles.linux": {
+            "bash": {
+                "path": "/bin/bash",
+                "icon": "terminal-bash",
+            },
+        },
+    },
+    "extensions": [
+        "dbaeumer.vscode-eslint"
+    ],
+    "remoteUser": "node"
+}

.eslintrc.json

@@ -34,6 +34,9 @@
         ],
 
         "@typescript-eslint/consistent-type-definitions": ["error", "interface"],
+        "@typescript-eslint/consistent-type-assertions": ["error", { "assertionStyle": "as" }],
+
+        "max-statements-per-line": ["error", { "max": 1 }],
 
         "no-duplicate-imports": "off",
         "@typescript-eslint/no-duplicate-imports": "error",

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -7,38 +7,69 @@ assignees: ''
 
 ---
 
-<!-- 🚨 STOP 🚨 STOP 🚨 STOP 🚨
+# Bug Report
 
-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 _______
 
-<!-- Search terms you tried before logging this (so others can find this issue more easily) -->
-**Search Terms:**
+### ⏯ Playground Link
+
+<!--
+  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

@@ -7,41 +7,55 @@ assignees: ''
 
 ---
 
-<!-- 🚨 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
+# Suggestion
 
+<!--
+  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/lib_change.md

@@ -0,0 +1,58 @@
+---
+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/ISSUE_TEMPLATE/types-not-correct-in-with-callback.md

@@ -0,0 +1,47 @@
+---
+name: Types Not Correct in/with Callback
+about: TypeScript assuming the wrong type either after a callback runs, or within
+  a callback
+title: ''
+labels: Duplicate
+assignees: ''
+
+---
+
+TypeScript has two narrowing-related behaviors that are both intentional. Please do not log additional bugs on this; see #9998 for more discussion.
+
+The first is that *narrowings are not respected in callbacks*. In other words:
+```ts
+function fn(obj: { name: string | number }) {
+  if (typeof obj.name === "string") {
+    // Errors
+    window.setTimeout(() => console.log(obj.name.toLowerCase());
+  }
+}
+```
+This is intentional since the value of `obj.name` "could" change types between when the narrowing occurred and when the callback was invoke. See also #11498
+
+The second is that *function calls do not reset narrowings*. In other words:
+```ts
+function fn(obj: { name: string | number }) {
+  if (typeof obj.name === "string") {
+    console.log("Here");
+    // Does not error
+    console.log(obj.name.toLowerCase());
+  }
+}
+```
+This is intentional behavior, *even though `console.log` could have mutated obj*. This rule is consistently applied, even with the function is in-principle inspectable to actually have side effects
+```ts
+function fn(obj: { name: string | number }) {
+  if (typeof obj.name === "string") {
+    mut();
+    // Does not error
+    console.log(obj.name.toLowerCase());
+  }
+
+  function mut() {
+    obj.name = 42;
+  }
+}
+```

.github/issue_template.md

@@ -10,4 +10,7 @@ ahejlsberg
 amcasey
 jessetrinity
 minestarks
-uniqueiniquity
+armanio123
+gabritto
+jakebailey
+DanielRosenwasser

.github/pr_owners.txt

@@ -3,12 +3,19 @@ Thank you for submitting a pull request!
 
 Please verify that:
 * [ ] There is an associated issue in the `Backlog` milestone (**required**)
-* [ ] Code is up-to-date with the `master` branch
+* [ ] Code is up-to-date with the `main` branch
 * [ ] You've successfully run `gulp runtests` locally
 * [ ] There are new or updated unit tests validating the change
 
 Refer to CONTRIBUTING.MD for more details.
-  https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md
+  https://github.com/Microsoft/TypeScript/blob/main/CONTRIBUTING.md
+
+** Please don't send typo fixes! **
+Please don't send a PR solely for the purpose of fixing a typo, unless that
+typo truly hurts understanding of the text. Each PR represents work for the
+maintainers, and that work should provide commensurate value.
+
+If you're interested in sending a PR, the issue tracker has many issues marked `help wanted`.
 -->
 
 Fixes #