feat: implement proposal-class-static-block

packages/babel-plugin-proposal-class-static-block/.npmignore

@@ -0,0 +1,3 @@
+src
+test
+*.log

packages/babel-plugin-proposal-class-static-block/README.md

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+# @babel/plugin-proposal-class-static-block
+
+> Allow transforming of class static blocks
+
+See our website [@babel/plugin-proposal-class-static-block](https://babeljs.io/docs/en/next/babel-plugin-proposal-class-static-block.html) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/plugin-proposal-class-static-block
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/plugin-proposal-class-static-block --dev
+```

packages/babel-plugin-proposal-class-static-block/package.json

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+{
+  "name": "@babel/plugin-proposal-class-static-block",
+  "version": "7.11.0",
+  "description": "Allow parsing of class static blocks",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/babel/babel.git",
+    "directory": "packages/babel-plugin-proposal-class-static-block"
+  },
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "./lib/index.js",
+  "exports": {
+    ".": "./lib/index.js"
+  },
+  "keywords": [
+    "babel-plugin"
+  ],
+  "dependencies": {
+    "@babel/helper-plugin-utils": "workspace:^7.10.1",
+    "@babel/plugin-syntax-class-static-block": "workspace:^7.11.0"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0-0"
+  }
+}

packages/babel-plugin-proposal-class-static-block/src/index.js

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+import { declare } from "@babel/helper-plugin-utils";
+import syntaxClassStaticBlock from "@babel/plugin-syntax-class-static-block";
+
+export default declare(({ types: t, template, assertVersion }) => {
+  assertVersion(7);
+
+  return {
+    name: "proposal-class-static-block",
+    inherits: syntaxClassStaticBlock,
+    visitor: {
+      StaticBlock(path) {
+        const staticBlockRef = path.scope.generateUidIdentifier("init");
+        const classPath = path.parentPath.parentPath;
+        path.replaceWith(
+          t.classMethod(
+            "method",
+            staticBlockRef,
+            [],
+            t.BlockStatement(
+              // Add completion record. A static block can not contain directly
+              // `return`, `break`, `continue`. So `return this` must be executed.
+              path.node.body.concat([
+                template.ast`delete this.${t.cloneNode(staticBlockRef)};`,
+                template.ast`return this;`,
+              ]),
+            ),
+            /* computed */ false,
+            /* static */ true,
+          ),
+        );
+        const classId = classPath.node.id;
+        if (!classId) {
+          // If `classId` is not defined, we don't have to preserve the class binding
+          // `class { }` transformed as `(class { })._init()`
+          classPath.replaceWith(
+            template.ast`(${classPath.node}).${t.cloneNode(staticBlockRef)}()`,
+          );
+        } else {
+          // If `classId` is defined, preserve the class binding.
+          // `class Foo { }` transformed as `(Foo = (class Foo { })._init())`
+          classPath.node.type = "ClassExpression";
+          classPath.replaceWith(
+            template.ast`${t.cloneNode(classId)} = (${
+              classPath.node
+            }).${t.cloneNode(staticBlockRef)}()`,
+          );
+          classPath.insertBefore(template.ast`let ${t.cloneNode(classId)};`);
+        }
+      },
+    },
+  };
+});

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/class-declaration/exec.js

@@ -0,0 +1,6 @@
+class Foo {
+  static {
+    this.foo = 42;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/class-declaration/input.js

@@ -0,0 +1,6 @@
+class Foo {
+  static {
+    this.foo = 42;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/class-declaration/output.js

@@ -0,0 +1,10 @@
+let Foo;
+Foo = class Foo {
+  static _init() {
+    this.foo = 42;
+    delete this._init;
+    return this;
+  }
+
+}._init();
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/class-expression/exec.js

@@ -0,0 +1,6 @@
+class Foo {
+  static {
+    this.foo = 42;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/class-expression/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-static-block", "syntax-class-properties"]
+}

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage-named/exec.js

@@ -0,0 +1,10 @@
+class Foo extends class {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = 2 * this.bar;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage-named/input.js

@@ -0,0 +1,10 @@
+class Foo extends class Bar {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = 2 * this.bar;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage-named/output.js

@@ -0,0 +1,18 @@
+let Foo;
+let Bar;
+Foo = class Foo extends (Bar = class Bar {
+  static _init2() {
+    this.bar = 21;
+    delete this._init2;
+    return this;
+  }
+
+}._init2()) {
+  static _init() {
+    this.foo = 2 * this.bar;
+    delete this._init;
+    return this;
+  }
+
+}._init();
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage/exec.js

@@ -0,0 +1,10 @@
+class Foo extends class {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = 2 * this.bar;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage/input.js

@@ -0,0 +1,10 @@
+class Foo extends class {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = 2 * this.bar;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/in-class-heritage/output.js

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+let Foo;
+Foo = class Foo extends class {
+  static _init2() {
+    this.bar = 21;
+    delete this._init2;
+    return this;
+  }
+
+}._init2() {
+  static _init() {
+    this.foo = 2 * this.bar;
+    delete this._init;
+    return this;
+  }
+
+}._init();
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/private-elements-access/exec.js

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+let getFoo;
+class Foo {
+  static #foo = 42;
+  static {
+    getFoo = () => this.#foo;
+  }
+}
+expect(getFoo()).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/private-elements-access/options.json

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+{
+  "plugins": ["proposal-class-static-block", "syntax-class-properties"],
+  "minNodeVersion": "12.0.0"
+}

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/super-property/exec.js

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+class Foo extends class {
+  static {
+    this.bar = 42;
+  }
+} {
+  static bar = 21;
+  static {
+    this.foo = super.bar;
+  }
+}
+expect(Foo.foo).toBe(42);

packages/babel-plugin-proposal-class-static-block/test/fixtures/class-static-block/super-property/options.json

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+{
+  "plugins": ["proposal-class-static-block", "syntax-class-properties"]
+}

packages/babel-plugin-proposal-class-static-block/test/fixtures/options.json

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+{
+  "plugins": ["proposal-class-static-block"]
+}

packages/babel-plugin-proposal-class-static-block/test/index.js

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+import runner from "@babel/helper-plugin-test-runner";
+
+runner(__dirname);

yarn.lock

@@ -1004,6 +1004,17 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@babel/plugin-proposal-class-static-block@workspace:packages/babel-plugin-proposal-class-static-block":
+  version: 0.0.0-use.local
+  resolution: "@babel/plugin-proposal-class-static-block@workspace:packages/babel-plugin-proposal-class-static-block"
+  dependencies:
+    "@babel/helper-plugin-utils": "workspace:^7.10.1"
+    "@babel/plugin-syntax-class-static-block": "workspace:^7.11.0"
+  peerDependencies:
+    "@babel/core": ^7.0.0-0
+  languageName: unknown
+  linkType: soft
+
 "@babel/plugin-proposal-decorators@workspace:^7.10.4, @babel/plugin-proposal-decorators@workspace:^7.10.5, @babel/plugin-proposal-decorators@workspace:packages/babel-plugin-proposal-decorators":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-proposal-decorators@workspace:packages/babel-plugin-proposal-decorators"
@@ -1449,7 +1460,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@babel/plugin-syntax-class-static-block@workspace:packages/babel-plugin-syntax-class-static-block":
+"@babel/plugin-syntax-class-static-block@workspace:^7.11.0, @babel/plugin-syntax-class-static-block@workspace:packages/babel-plugin-syntax-class-static-block":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-syntax-class-static-block@workspace:packages/babel-plugin-syntax-class-static-block"
   dependencies: