Merge branch 'master' into next-8-dev

CONTRIBUTING.md

@@ -16,9 +16,7 @@
 
 # Contributing
 
-Contributions are always welcome, no matter how large or small. Before
-contributing, please read the
-[code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
+Contributions are always welcome, no matter how large or small! Before contributing, please read the [code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
 
 ## Not sure where to start?
 
@@ -39,12 +37,9 @@ Feel free to check out the `#discussion`/`#development` channels on our [Slack](
 
 ## Developing
 
-**Note:** Versions `< 5.1.10` can't be built.
+*Node*: Check that Node is [installed](https://nodejs.org/en/download/) with version 10 and up. You can check this with `node -v`.
 
-Babel is built for Node 6 and up but we develop using Node 8 and yarn. You can check this with `node -v`.
-
-Make sure that Yarn is installed with version >= `0.28.0`.
-Installation instructions can be found here: https://yarnpkg.com/en/docs/install.
+*Yarn*: Make sure that Yarn 1 is [installed](https://classic.yarnpkg.com/en/docs/install) with version >= `1.19.0`.
 
 ### Setup
 
@@ -72,7 +67,7 @@ $ make watch
 
 to have Babel build itself and incrementally build files on change.
 
-You can access the built files for individual packages from `packages/<package-name>/lib`.
+> You can access the built files for individual packages from `packages/<package-name>/lib`.
 
 If you wish to build a copy of Babel for distribution, then run:
 
@@ -109,9 +104,7 @@ If you just want to run all tests:
 $ make test-only
 ```
 
-Most likely you'll want to focus in on a specific issue.
-
-To run tests for a specific package in [packages](https://github.com/babel/babel/tree/master/packages), you can use the `TEST_ONLY` environment variable:
+When working on an issue, you will most likely want to focus on a particular [packages](https://github.com/babel/babel/tree/master/packages). Using `TEST_ONLY` will only run tests for that specific package.
 
 ```sh
 $ TEST_ONLY=babel-cli make test

Gulpfile.js

@@ -227,19 +227,6 @@ gulp.task("build-rollup", () => buildRollup(libBundles));
 gulp.task("build-babel-standalone", () => buildRollup(standaloneBundle));
 
 gulp.task("build-babel", () => buildBabel(/* exclude */ libBundles));
-gulp.task("build-babel-types-deps", () =>
-  buildBabel(
-    /* exclude */ libBundles,
-    "packages/babel-helper-validator-identifier/src/**/*.js"
-  )
-);
-gulp.task("build-babel-types-self", () =>
-  buildBabel(/* exclude */ libBundles, "packages/babel-types/src/**/*.js")
-);
-gulp.task(
-  "build-babel-types",
-  gulp.series("build-babel-types-deps", "build-babel-types-self")
-);
 gulp.task("build", gulp.parallel("build-rollup", "build-babel"));
 
 gulp.task("default", gulp.series("build"));

Makefile

@@ -78,6 +78,9 @@ build-no-bundle: clean clean-lib
 	$(MAKE) generate-type-helpers
 	$(MAKE) build-typings
 
+build-no-bundle-ci: bootstrap-only
+	$(MAKE) build-no-bundle
+
 watch: build-no-bundle
 	BABEL_ENV=development $(YARN) gulp watch
 
@@ -91,9 +94,7 @@ code-quality: flow lint
 flow:
 	$(YARN) flow check --strip-root
 
-bootstrap-flowcheck: bootstrap-only
-	$(YARN) gulp build-babel-types
-	$(MAKE) build-typings
+bootstrap-flowcheck: build-no-bundle-ci
 
 lint-ci: lint-js-ci lint-ts-ci check-compat-data-ci
 
@@ -103,7 +104,7 @@ lint-js-ci: bootstrap-only
 lint-ts-ci: bootstrap-flowcheck
 	$(MAKE) lint-ts
 
-check-compat-data-ci: bootstrap-only
+check-compat-data-ci: build-no-bundle-ci
 	$(MAKE) check-compat-data
 
 lint: lint-js lint-ts

babel.config.js

@@ -8,6 +8,7 @@ module.exports = function(api) {
   const envOptsNoTargets = {
     loose: true,
     modules: false,
+    shippedProposals: true,
     exclude: ["transform-typeof-symbol"],
   };
   const envOpts = Object.assign({}, envOptsNoTargets);
@@ -100,14 +101,10 @@ module.exports = function(api) {
       "@babel/plugin-transform-flow-strip-types",
       ["@babel/proposal-class-properties", { loose: true }],
       "@babel/proposal-export-namespace-from",
-      "@babel/proposal-numeric-separator",
       [
         "@babel/proposal-object-rest-spread",
         { useBuiltIns: true, loose: true },
       ],
-      ["@babel/plugin-proposal-optional-chaining", { loose: true }],
-      ["@babel/plugin-proposal-nullish-coalescing-operator", { loose: true }],
-
       compileDynamicImport ? dynamicImportUrlToPath : null,
       compileDynamicImport ? "@babel/plugin-proposal-dynamic-import" : null,
 

package.json

@@ -11,23 +11,20 @@
   },
   "devDependencies": {
     "@babel/cli": "^7.8.4",
-    "@babel/core": "^7.8.7",
+    "@babel/core": "^7.9.0",
     "@babel/eslint-plugin-development": "^1.0.1",
     "@babel/plugin-proposal-class-properties": "^7.8.3",
     "@babel/plugin-proposal-dynamic-import": "^7.8.3",
     "@babel/plugin-proposal-export-namespace-from": "^7.8.3",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.8.3",
-    "@babel/plugin-proposal-numeric-separator": "^7.8.3",
-    "@babel/plugin-proposal-object-rest-spread": "^7.8.3",
-    "@babel/plugin-proposal-optional-chaining": "^7.8.3",
-    "@babel/plugin-transform-flow-strip-types": "^7.8.3",
-    "@babel/plugin-transform-for-of": "^7.8.6",
-    "@babel/plugin-transform-modules-commonjs": "^7.8.3",
-    "@babel/plugin-transform-runtime": "^7.8.3",
-    "@babel/preset-env": "^7.8.7",
-    "@babel/preset-flow": "^7.8.3",
-    "@babel/register": "^7.8.6",
-    "@babel/runtime": "^7.8.7",
+    "@babel/plugin-proposal-object-rest-spread": "^7.9.5",
+    "@babel/plugin-transform-flow-strip-types": "^7.9.0",
+    "@babel/plugin-transform-for-of": "^7.9.0",
+    "@babel/plugin-transform-modules-commonjs": "^7.9.0",
+    "@babel/plugin-transform-runtime": "^7.9.0",
+    "@babel/preset-env": "^7.9.5",
+    "@babel/preset-flow": "^7.9.0",
+    "@babel/register": "^7.9.0",
+    "@babel/runtime": "^7.9.2",
     "@rollup/plugin-json": "4.0.1",
     "babel-eslint": "^11.0.0-beta.2",
     "babel-jest": "^25.1.0",

packages/babel-core/src/parser/util/missing-plugin-helper.js

@@ -67,8 +67,8 @@ const pluginNameMap = {
       url: "https://git.io/vb4yb",
     },
     transform: {
-      name: "@babel/plugin-transform-flow-strip-types",
-      url: "https://git.io/vb49g",
+      name: "@babel/preset-flow",
+      url: "https://git.io/JfeDn",
     },
   },
   functionBind: {
@@ -103,8 +103,8 @@ const pluginNameMap = {
       url: "https://git.io/vb4yA",
     },
     transform: {
-      name: "@babel/plugin-transform-react-jsx",
-      url: "https://git.io/vb4yd",
+      name: "@babel/preset-react",
+      url: "https://git.io/JfeDR",
     },
   },
   logicalAssignment: {
@@ -159,8 +159,8 @@ const pluginNameMap = {
       url: "https://git.io/vb4SC",
     },
     transform: {
-      name: "@babel/plugin-transform-typescript",
-      url: "https://git.io/vb4Sm",
+      name: "@babel/preset-typescript",
+      url: "https://git.io/JfeDz",
     },
   },
 
@@ -194,13 +194,15 @@ export default function generateMissingPluginMessage(
   if (pluginInfo) {
     const { syntax: syntaxPlugin, transform: transformPlugin } = pluginInfo;
     if (syntaxPlugin) {
+      const syntaxPluginInfo = getNameURLCombination(syntaxPlugin);
       if (transformPlugin) {
         const transformPluginInfo = getNameURLCombination(transformPlugin);
-        helpMessage +=
-          `\n\nAdd ${transformPluginInfo} to the 'plugins' section of your Babel config ` +
-          `to enable transformation.`;
+        const sectionType = transformPlugin.name.startsWith("@babel/plugin")
+          ? "plugins"
+          : "presets";
+        helpMessage += `\n\nAdd ${transformPluginInfo} to the '${sectionType}' section of your Babel config to enable transformation.
+If you want to leave it as-is, add ${syntaxPluginInfo} to the 'plugins' section to enable parsing.`;
       } else {
-        const syntaxPluginInfo = getNameURLCombination(syntaxPlugin);
         helpMessage +=
           `\n\nAdd ${syntaxPluginInfo} to the 'plugins' section of your Babel config ` +
           `to enable parsing.`;

packages/babel-helper-create-class-features-plugin/src/fields.js

@@ -85,24 +85,49 @@ const privateNameVisitor = {
     const { privateNamesMap } = this;
     const body = path.get("body.body");
 
+    const visiblePrivateNames = new Map(privateNamesMap);
+    const redeclared = [];
     for (const prop of body) {
-      if (!prop.isPrivate()) {
-        continue;
-      }
-      if (!privateNamesMap.has(prop.node.key.id.name)) continue;
+      if (!prop.isPrivate()) continue;
+      const { name } = prop.node.key.id;
+      visiblePrivateNames.delete(name);
+      redeclared.push(name);
+    }
 
-      // This class redeclares the private name.
-      // So, we can only evaluate the things in the outer scope.
-      path.traverse(privateNameInnerVisitor, this);
-      path.skip();
-      break;
+    // If the class doesn't redeclare any private fields, we can continue with
+    // our overall traversal.
+    if (!redeclared.length) {
+      return;
     }
+
+    // This class redeclares some private field. We need to process the outer
+    // environment with access to all the outer privates, then we can process
+    // the inner environment with only the still-visible outer privates.
+    path.get("body").traverse(privateNameNestedVisitor, {
+      ...this,
+      redeclared,
+    });
+    path.traverse(privateNameVisitor, {
+      ...this,
+      privateNamesMap: visiblePrivateNames,
+    });
+
+    // We'll eventually hit this class node again with the overall Class
+    // Features visitor, which'll process the redeclared privates.
+    path.skipKey("body");
   },
 };
 
 // Traverses the outer portion of a class, without touching the class's inner
 // scope, for private names.
-const privateNameInnerVisitor = traverse.visitors.merge([
+const privateNameNestedVisitor = traverse.visitors.merge([
+  {
+    PrivateName(path) {
+      const { redeclared } = this;
+      const { name } = path.node.id;
+      if (redeclared.includes(name)) path.skip();
+    },
+  },
   {
     PrivateName: privateNameVisitor.PrivateName,
   },
@@ -263,6 +288,8 @@ export function transformPrivateNamesUsage(
   loose,
   state,
 ) {
+  if (!privateNamesMap.size) return;
+
   const body = path.get("body");
 
   if (loose) {

packages/babel-parser/src/parser/statement.js

@@ -1834,10 +1834,28 @@ export default class StatementParser extends ExpressionParser {
 
   isExportDefaultSpecifier(): boolean {
     if (this.match(tt.name)) {
-      return this.state.value !== "async" && this.state.value !== "let";
-    }
-
-    if (!this.match(tt._default)) {
+      const value = this.state.value;
+      if (value === "async" || value === "let") {
+        return false;
+      }
+      if (
+        (value === "type" || value === "interface") &&
+        !this.state.containsEsc
+      ) {
+        const l = this.lookahead();
+        // If we see any variable name other than `from` after `type` keyword,
+        // we consider it as flow/typescript type exports
+        // note that this approach may fail on some pedantic cases
+        // export type from = number
+        if (
+          (l.type === tt.name && l.value !== "from") ||
+          l.type === tt.braceL
+        ) {
+          this.expectOnePlugin(["flow", "typescript"]);
+          return false;
+        }
+      }
+    } else if (!this.match(tt._default)) {
       return false;
     }
 

packages/babel-parser/test/fixtures/flow/expect-plugin/export-interface/input.js

@@ -0,0 +1 @@
+export interface Foo {}

packages/babel-parser/test/fixtures/flow/expect-plugin/export-interface/options.json

@@ -0,0 +1,7 @@
+{
+  "sourceType": "module",
+  "plugins": [
+    "jsx"
+  ],
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (1:7)"
+}

packages/babel-parser/test/fixtures/flow/expect-plugin/export-type-named/input.js

@@ -0,0 +1,2 @@
+var Foo;
+export type { Foo };

packages/babel-parser/test/fixtures/flow/expect-plugin/export-type-named/options.json

@@ -0,0 +1,7 @@
+{
+  "sourceType": "module",
+  "plugins": [
+    "jsx"
+  ],
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (2:7)"
+}

packages/babel-parser/test/fixtures/flow/expect-plugin/export-type/input.js

@@ -0,0 +1 @@
+export type Foo = number;

packages/babel-parser/test/fixtures/flow/expect-plugin/export-type/options.json

@@ -0,0 +1,7 @@
+{
+  "sourceType": "module",
+  "plugins": [
+    "jsx"
+  ],
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (1:7)"
+}

packages/babel-parser/test/fixtures/flow/expect-plugin/options.json

@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "plugins": ["jsx"]
+}

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-interface/input.js

@@ -0,0 +1 @@
+export interface Foo {}

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-interface/options.json

@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (1:7)"
+}

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-type-named/input.js

@@ -0,0 +1,2 @@
+var Foo;
+export type { Foo };

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-type-named/options.json

@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (2:7)"
+}

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-type/input.js

@@ -0,0 +1 @@
+export type Foo = number;

packages/babel-parser/test/fixtures/typescript/expect-plugin/export-type/options.json

@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "throws": "This experimental syntax requires enabling one of the following parser plugin(s): 'flow, typescript' (1:7)"
+}

packages/babel-parser/test/fixtures/typescript/expect-plugin/options.json

@@ -0,0 +1,3 @@
+{
+  "sourceType": "module"
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/nested-class-computed-redeclared/exec.js

@@ -0,0 +1,19 @@
+class Foo {
+  #foo = 1;
+
+  test() {
+    class Nested {
+      #foo = 2;
+
+      [this.#foo]() {
+      }
+    }
+
+    return new Nested();
+  }
+}
+
+const f = new Foo();
+expect(() => {
+  f.test();
+}).toThrow();