Transform 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

@@ -0,0 +1,19 @@
+# @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

@@ -0,0 +1,28 @@
+{
+  "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": "^7.12.0"
+  }
+}

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

@@ -0,0 +1,66 @@
+import { declare } from "@babel/helper-plugin-utils";
+import syntaxClassStaticBlock from "@babel/plugin-syntax-class-static-block";
+
+/**
+ * Generate a uid that is not in `denyList`
+ *
+ * @param {*} scope
+ * @param {Set<string>} a deny list that the generated uid should avoid
+ * @returns
+ */
+function generateUid(scope, denyList: Set<string>) {
+  const name = "";
+  let uid;
+  let i = 1;
+  do {
+    uid = scope._generateUid(name, i);
+    i++;
+  } while (denyList.has(uid));
+  return uid;
+}
+
+/**
+ * Get private names defined in current class body
+ *
+ * @param {NodePath<ClassBody>} classBody
+ * @returns {Set<string>} A set of defined private names
+ */
+function getPrivateNames(classBody: NodePath<ClassBody>): Set<string> {
+  const privateNames = new Set();
+  for (const path of classBody.get("body")) {
+    if (path.isPrivate()) {
+      privateNames.add(path.get("key.id").node.name);
+    }
+  }
+  return privateNames;
+}
+
+export default declare(({ types: t, template, assertVersion }) => {
+  // todo remove this check after Babel 7.12.0 is published
+  if (process.env.NODE_ENV !== "test") {
+    assertVersion("^7.12.0");
+  }
+
+  return {
+    name: "proposal-class-static-block",
+    inherits: syntaxClassStaticBlock,
+    visitor: {
+      StaticBlock(path: NodePath<StaticBlock>) {
+        const { parentPath: classBody, scope } = path;
+        const staticBlockRef = t.privateName(
+          t.identifier(generateUid(scope, getPrivateNames(classBody))),
+        );
+        classBody.pushContainer(
+          "body",
+          t.classPrivateProperty(
+            staticBlockRef,
+            template.expression.ast`(() => { ${path.node.body} })()`,
+            [],
+            /* static */ true,
+          ),
+        );
+        path.remove();
+      },
+    },
+  };
+});

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

@@ -0,0 +1,7 @@
+class Foo {
+  static {
+    this.foo = Foo.bar;
+  }
+  static bar = 42;
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,7 @@
+class Foo {
+  static {
+    this.foo = this.bar;
+  }
+  static bar = 42;
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,7 @@
+class Foo {
+  static {
+    this.foo = this.bar;
+  }
+  static bar = 42;
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,8 @@
+class Foo {
+  static bar = 42;
+  static #_ = (() => {
+    this.foo = this.bar;
+  })();
+}
+
+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/in-class-heritage/exec.js

@@ -0,0 +1,14 @@
+class Foo extends class extends class Base {
+  static {
+    this.qux = 21;
+  }
+} {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = this.bar + this.qux;
+  }
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,14 @@
+class Foo extends class extends class Base {
+  static {
+    this.qux = 21;
+  }
+} {
+  static {
+    this.bar = 21;
+  }
+} {
+  static {
+    this.foo = this.bar + this.qux;
+  }
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,15 @@
+class Foo extends class extends class Base {
+  static #_ = (() => {
+    this.qux = 21;
+  })();
+} {
+  static #_ = (() => {
+    this.bar = 21;
+  })();
+} {
+  static #_ = (() => {
+    this.foo = this.bar + this.qux;
+  })();
+}
+
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,8 @@
+class Foo {
+  static #bar = 21;
+  static {
+    this.foo = this.#bar + this.qux;
+  }
+  static qux = 21;
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,8 @@
+class Foo {
+  static #_ = 42;
+  // static block can not be tranformed as `#_` here
+  static {
+    this.foo = this.#_;
+  }
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,8 @@
+class Foo {
+  static #_ = 42;
+  // static block can not be tranformed as `#_` here
+  static {
+    this.foo = this.#_;
+  }
+}
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,9 @@
+class Foo {
+  static #_ = 42; // static block can not be tranformed as `#_` here
+
+  static #_2 = (() => {
+    this.foo = this.#_;
+  })();
+}
+
+expect(Foo.foo).toBe(42);

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

@@ -0,0 +1,4 @@
+{
+  "plugins": ["proposal-class-static-block", "syntax-class-properties"],
+  "minNodeVersion": "12.0.0"
+}

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

@@ -0,0 +1,8 @@
+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/super-property/exec.js

@@ -0,0 +1,11 @@
+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/options.json

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

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

@@ -0,0 +1,3 @@
+import runner from "@babel/helper-plugin-test-runner";
+
+runner(__dirname);

packages/babel-traverse/src/scope/index.js

@@ -368,7 +368,7 @@ export default class Scope {
       .replace(/[0-9]+$/g, "");
 
     let uid;
-    let i = 0;
+    let i = 1;
     do {
       uid = this._generateUid(name, i);
       i++;

packages/babel-types/src/definitions/experimental.js

@@ -108,7 +108,7 @@ defineType("PipelinePrimaryTopicReference", {
 
 defineType("ClassPrivateProperty", {
   visitor: ["key", "value", "decorators"],
-  builder: ["key", "value", "decorators"],
+  builder: ["key", "value", "decorators", "static"],
   aliases: ["Property", "Private"],
   fields: {
     key: {

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": ^7.12.0
+  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: