Merge branch 'master' into jsx-element-realtypes

Author: weswigham

.github/pull_request_template.md

@@ -1,8 +1,8 @@
 <!--
 Thank you for submitting a pull request!
 
-Here's a checklist you might find useful.
-* [ ] There is an associated issue that is labeled 'Bug' or 'help wanted'
+Please verify that:
+* [ ] There is an associated issue in the `Backlog` milestone (**required**)
 * [ ] Code is up-to-date with the `master` branch
 * [ ] You've successfully run `gulp runtests` locally
 * [ ] There are new or updated unit tests validating the change
@@ -12,4 +12,3 @@ Refer to CONTRIBUTING.MD for more details.
 -->
 
 Fixes #
-

CONTRIBUTING.md

@@ -59,11 +59,11 @@ Run `gulp` to build a version of the compiler/language service that reflects cha
 
 ## Contributing bug fixes
 
-TypeScript is currently accepting contributions in the form of bug fixes. A bug must have an issue tracking it in the issue tracker that has been approved ("Milestone == Community") by the TypeScript team. Your pull request should include a link to the bug that you are fixing. If you've submitted a PR for a bug, please post a comment in the bug to avoid duplication of effort.
+TypeScript is currently accepting contributions in the form of bug fixes. A bug must have an issue tracking it in the issue tracker that has been approved (labelled ["help wanted"](https://github.com/Microsoft/TypeScript/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22)) by the TypeScript team. Your pull request should include a link to the bug that you are fixing. If you've submitted a PR for a bug, please post a comment in the bug to avoid duplication of effort.
 
 ## Contributing features
 
-Features (things that add new or improved functionality to TypeScript) may be accepted, but will need to first be approved (marked as "Milestone == Community" by a TypeScript coordinator with the message "Approved") in the suggestion issue. Features with language design impact, or that are adequately satisfied with external tools, will not be accepted.
+Features (things that add new or improved functionality to TypeScript) may be accepted, but will need to first be approved ([labelled "help wanted"](https://github.com/Microsoft/TypeScript/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22) by a TypeScript project maintainer) in the suggestion issue. Features with language design impact, or that are adequately satisfied with external tools, will not be accepted.
 
 Design changes will not be accepted at this time. If you have a design change proposal, please log a suggestion issue.
 

Gulpfile.js

@@ -545,6 +545,10 @@ const configureInsiders = () => exec(process.execPath, ["scripts/configurePrerel
 task("configure-insiders", series(buildScripts, configureInsiders));
 task("configure-insiders").description = "Runs scripts/configurePrerelease.ts to prepare a build for insiders publishing";
 
+const configureExperimental = () => exec(process.execPath, ["scripts/configurePrerelease.js", "experimental", "package.json", "src/compiler/core.ts"])
+task("configure-experimental", series(buildScripts, configureExperimental));
+task("configure-experimental").description = "Runs scripts/configurePrerelease.ts to prepare a build for experimental publishing";
+
 const publishNightly = () => exec("npm", ["publish", "--tag", "next"]);
 task("publish-nightly", series(task("clean"), task("LKG"), task("clean"), task("runtests-parallel"), publishNightly));
 task("publish-nightly").description = "Runs `npm publish --tag next` to create a new nightly build on npm";

README.md

@@ -79,8 +79,6 @@ gulp tests            # Build the test infrastructure using the built compiler.
 gulp runtests         # Run tests using the built compiler and test infrastructure. 
                       # You can override the host or specify a test for this command. 
                       # Use --host=<hostName> or --tests=<testPath>. 
-gulp runtests-browser # Runs the tests using the built run.js file. Syntax is gulp runtests. Optional
-                        parameters '--host=', '--tests=[regex], --reporter=[list|spec|json|<more>]'.
 gulp baseline-accept  # This replaces the baseline test results with the results obtained from gulp runtests.
 gulp lint             # Runs tslint on the TypeScript source.
 gulp help             # List the above commands. 

lib/tsserverlibrary.d.ts

@@ -626,7 +626,7 @@ declare namespace ts {
         initializer?: Expression;
     }
     interface ObjectLiteralElement extends NamedDeclaration {
-        _objectLiteralBrandBrand: any;
+        _objectLiteralBrand: any;
         name?: PropertyName;
     }
     /** Unlike ObjectLiteralElement, excludes JSXAttribute and JSXSpreadAttribute. */

lib/typescript.d.ts

@@ -626,7 +626,7 @@ declare namespace ts {
         initializer?: Expression;
     }
     interface ObjectLiteralElement extends NamedDeclaration {
-        _objectLiteralBrandBrand: any;
+        _objectLiteralBrand: any;
         name?: PropertyName;
     }
     /** Unlike ObjectLiteralElement, excludes JSXAttribute and JSXSpreadAttribute. */

lib/typescriptServices.d.ts

@@ -626,7 +626,7 @@ declare namespace ts {
         initializer?: Expression;
     }
     interface ObjectLiteralElement extends NamedDeclaration {
-        _objectLiteralBrandBrand: any;
+        _objectLiteralBrand: any;
         name?: PropertyName;
     }
     /** Unlike ObjectLiteralElement, excludes JSXAttribute and JSXSpreadAttribute. */

package.json

@@ -68,7 +68,6 @@
         "gulp-rename": "latest",
         "gulp-sourcemaps": "latest",
         "istanbul": "latest",
-        "lodash": "^4.17.11",
         "merge2": "latest",
         "minimist": "latest",
         "mkdirp": "latest",

scripts/configurePrerelease.ts

@@ -22,7 +22,7 @@ function main(): void {
     }
 
     const tag = args[0];
-    if (tag !== "dev" && tag !== "insiders") {
+    if (tag !== "dev" && tag !== "insiders" && tag !== "experimental") {
         throw new Error(`Unexpected tag name '${tag}'.`);
     }
 

scripts/open-user-pr.ts

@@ -1,16 +1,7 @@
 /// <reference lib="esnext.asynciterable" />
 // Must reference esnext.asynciterable lib, since octokit uses AsyncIterable internally
-import cp = require("child_process");
 import Octokit = require("@octokit/rest");
-
-const opts = { timeout: 100_000, shell: true, stdio: "inherit" }
-function runSequence(tasks: [string, string[]][]) {
-    for (const task of tasks) {
-        console.log(`${task[0]} ${task[1].join(" ")}`);
-        const result = cp.spawnSync(task[0], task[1], opts);
-        if (result.status !== 0) throw new Error(`${task[0]} ${task[1].join(" ")} failed: ${result.stderr && result.stderr.toString()}`);
-    }
-}
+import {runSequence} from "./run-sequence";
 
 function padNum(number: number) {
     const str = "" + number;

scripts/perf-result-post.js

@@ -22,9 +22,10 @@ gh.issues.createComment({
     owner: "Microsoft",
     repo: "TypeScript",
     body: `@${requester}
-The results of the perf run you requested are in! Here they are:
-
-${outputTableText}`
+The results of the perf run you requested are in!
+<details><summary> Here they are:</summary><p>
+${outputTableText}
+</p></details>`
 }).then(async data => {
     console.log(`Results posted!`);
     const newCommentUrl = data.data.html_url;

scripts/run-sequence.js

@@ -0,0 +1,19 @@
+// @ts-check
+const cp = require("child_process");
+/**
+ * 
+ * @param {[string, string[]][]} tasks
+ * @param {cp.SpawnSyncOptions} opts
+ */
+function runSequence(tasks, opts = { timeout: 100000, shell: true, stdio: "inherit" }) {
+    let lastResult;
+    for (const task of tasks) {
+        console.log(`${task[0]} ${task[1].join(" ")}`);
+        const result = cp.spawnSync(task[0], task[1], opts);
+        if (result.status !== 0) throw new Error(`${task[0]} ${task[1].join(" ")} failed: ${result.stderr && result.stderr.toString()}`);
+        lastResult = result;
+    }
+    return lastResult && lastResult.stdout && lastResult.stdout.toString();
+}
+
+exports.runSequence = runSequence;

scripts/update-experimental-branches.js

@@ -0,0 +1,97 @@
+// @ts-check
+/// <reference lib="esnext.asynciterable" />
+const Octokit = require("@octokit/rest");
+const {runSequence} = require("./run-sequence");
+
+/**
+ * This program should be invoked as `node ./scripts/update-experimental-branches <GithubAccessToken> <Branch1> [Branch2] [...]`
+ */
+async function main() {
+    const branchesRaw = process.argv[3];
+    const branches = process.argv.slice(3);
+    if (!branches.length) {
+        throw new Error(`No experimental branches, aborting...`);
+    }
+    console.log(`Performing experimental branch updating and merging for branches ${branchesRaw}`);
+
+    const gh = new Octokit();
+    gh.authenticate({
+        type: "token",
+        token: process.argv[2]
+    });
+    
+    // Fetch all relevant refs
+    runSequence([
+        ["git", ["fetch", "origin", "master:master", ...branches.map(b => `${b}:${b}`)]]
+    ])
+    
+    // Forcibly cleanup workspace
+    runSequence([
+        ["git", ["clean", "-fdx"]],
+        ["git", ["checkout", "."]],
+        ["git", ["checkout", "master"]],
+    ]);
+    
+    // Update branches
+    for (const branch of branches) {
+        // Checkout, then get the merge base
+        const mergeBase = runSequence([
+            ["git", ["checkout", branch]],
+            ["git", ["merge-base", branch, "master"]],
+        ]);
+        // Simulate the merge and abort if there are conflicts
+        const mergeTree = runSequence([
+            ["git", ["merge-tree", mergeBase, branch, "master"]]
+        ]);
+        if (mergeTree.indexOf(`===${"="}===`)) { // 7 equals is the center of the merge conflict marker
+            const res = await gh.pulls.list({owner: "Microsoft", repo: "TypeScript", base: branch});
+            if (res && res.data && res.data[0]) {
+                const pr = res.data[0];
+                await gh.issues.createComment({
+                    owner: "Microsoft",
+                    repo: "TypeScript",
+                    number: pr.number,
+                    body: `This PR is configured as an experiment, and currently has merge conflicts with master - please rebase onto master and fix the conflicts.`
+                });
+            }
+            throw new Error(`Merge conflict detected on branch ${branch} with master`);
+        }
+        // Merge is good - apply a rebase and (force) push
+        runSequence([
+            ["git", ["rebase", "master"]],
+            ["git", ["push", "-f", "-u", "origin", branch]],
+        ]);
+    }
+
+    // Return to `master` and make a new `experimental` branch
+    runSequence([
+        ["git", ["checkout", "master"]],
+        ["git", ["branch", "-D", "experimental"]],
+        ["git", ["checkout", "-b", "experimental"]],
+    ]);
+
+    // Merge each branch into `experimental` (which, if there is a conflict, we now know is from inter-experiment conflict)
+    for (const branch of branches) {
+        // Find the merge base
+        const mergeBase = runSequence([
+            ["git", ["merge-base", branch, "experimental"]],
+        ]);
+        // Simulate the merge and abort if there are conflicts
+        const mergeTree = runSequence([
+            ["git", ["merge-tree", mergeBase, branch, "experimental"]]
+        ]);
+        if (mergeTree.indexOf(`===${"="}===`)) { // 7 equals is the center of the merge conflict marker
+            throw new Error(`Merge conflict detected on branch ${branch} with other experiment`);
+        }
+        // Merge (always producing a merge commit)
+        runSequence([
+            ["git", ["merge", branch, "--no-ff"]],
+        ]);
+    }
+    // Every branch merged OK, force push the replacement `experimental` branch
+    runSequence([
+        ["git", ["push", "-f", "-u", "origin", "experimental"]],
+    ]);
+}
+
+main().catch(e => (console.error(e), process.exitCode = 2));

src/compiler/binder.ts

@@ -1625,15 +1625,8 @@ namespace ts {
         }
 
         function hasExportDeclarations(node: ModuleDeclaration | SourceFile): boolean {
-            const body = node.kind === SyntaxKind.SourceFile ? node : node.body;
-            if (body && (body.kind === SyntaxKind.SourceFile || body.kind === SyntaxKind.ModuleBlock)) {
-                for (const stat of (<BlockLike>body).statements) {
-                    if (stat.kind === SyntaxKind.ExportDeclaration || stat.kind === SyntaxKind.ExportAssignment) {
-                        return true;
-                    }
-                }
-            }
-            return false;
+            const body = isSourceFile(node) ? node : tryCast(node.body, isModuleBlock);
+            return !!body && body.statements.some(s => isExportDeclaration(s) || isExportAssignment(s));
         }
 
         function setExportContextFlag(node: ModuleDeclaration | SourceFile) {