Convert the constants transform plugin to a validation plugin

A follow up from https://github.com/babel/babel/pull/2969 were we added support for consts in the block-scoping plugin.

packages/babel-plugin-check-es2015-constants/README.md

@@ -0,0 +1,39 @@
+# babel-plugin-check-es2015-constants
+
+Validate ES2015 constants
+
+## Installation
+
+```sh
+$ npm install babel-plugin-check-es2015-constants
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```json
+{
+  "plugins": ["check-es2015-constants"]
+}
+```
+
+### Via CLI
+
+```sh
+$ babel --plugins check-es2015-constants script.js
+```
+
+### Via Node API
+
+```javascript
+require("babel-core").transform("code", {
+  plugins: ["check-es2015-constants"]
+});
+```
+
+## Note
+
+This check will only validate consts. If you need it to compile down to `var` then you must also install and enable [`check-es2015-block-scoping`](../babel-plugin-check-es2015-block-scoping).

packages/babel-plugin-check-es2015-constants/package.json

@@ -1,8 +1,8 @@
 {
-  "name": "babel-plugin-transform-es2015-constants",
+  "name": "babel-plugin-check-es2015-constants",
   "version": "6.1.4",
   "description": "Compile ES2015 constants to ES5",
-  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-es2015-constants",
+  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-check-es2015-constants",
   "license": "MIT",
   "main": "lib/index.js",
   "keywords": [

packages/babel-plugin-check-es2015-constants/src/index.js

@@ -0,0 +1,16 @@
+export default function ({ messages }) {
+  return {
+    visitor: {
+      Scope({ scope }) {
+        for (let name in scope.bindings) {
+          let binding = scope.bindings[name];
+          if (binding.kind !== "const" && binding.kind !== "module") continue;
+
+          for (let violation of (binding.constantViolations: Array)) {
+            throw violation.buildCodeFrameError(messages.get("readOnly", name));
+          }
+        }
+      },
+    }
+  };
+}

packages/babel-plugin-check-es2015-constants/test/fixtures/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["check-es2015-constants", "transform-es2015-block-scoping", "transform-es2015-destructuring"]
+}

packages/babel-plugin-transform-es2015-block-scoping/test/fixtures/pass/options.json

@@ -1,3 +1,3 @@
 {
-  "plugins": ["transform-es2015-constants", "transform-es2015-block-scoping", "transform-es2015-parameters", "transform-es2015-destructuring", "transform-es2015-modules-commonjs"]
+  "plugins": ["check-es2015-constants", "transform-es2015-block-scoping", "transform-es2015-parameters", "transform-es2015-destructuring", "transform-es2015-modules-commonjs"]
 }

packages/babel-plugin-transform-es2015-constants/README.md

@@ -1,39 +0,0 @@
-# babel-plugin-transform-es2015-constants
-
-Compile ES2015 constants to ES5
-
-## Installation
-
-```sh
-$ npm install babel-plugin-transform-es2015-constants
-```
-
-## Usage
-
-### Via `.babelrc` (Recommended)
-
-**.babelrc**
-
-```json
-{
-  "plugins": ["transform-es2015-constants"]
-}
-```
-
-### Via CLI
-
-```sh
-$ babel --plugins transform-es2015-constants script.js
-```
-
-### Via Node API
-
-```javascript
-require("babel-core").transform("code", {
-  plugins: ["transform-es2015-constants"]
-});
-```
-
-## Note
-
-This transform on its own will compile `const` to `let`. If you need it to compile down to `var` then you must also install and enable [`transform-es2015-block-scoping`](../babel-plugin-transform-es2015-block-scoping).

packages/babel-plugin-transform-es2015-constants/src/index.js

@@ -1,38 +0,0 @@
-export default function ({ messages, types: t }) {
-  function check(node) {
-    if (t.isVariableDeclaration(node, { kind: "const" })) {
-      node.kind = "let";
-    }
-  }
-
-  return {
-    visitor: {
-      Scope({ scope }) {
-        for (let name in scope.bindings) {
-          let binding = scope.bindings[name];
-          if (binding.kind !== "const" && binding.kind !== "module") continue;
-
-          for (let violation of (binding.constantViolations: Array)) {
-            throw violation.buildCodeFrameError(messages.get("readOnly", name));
-          }
-        }
-      },
-
-      VariableDeclaration({ node }) {
-        check(node);
-      },
-
-      ForXStatement({ node: { left } }) {
-        check(left);
-      },
-
-      ForStatement({ node: { init } }) {
-        check(init);
-      },
-
-      "BlockStatement|Program"({ node: { body } }) {
-        for (let node of body) check(node);
-      }
-    }
-  };
-}

packages/babel-plugin-transform-es2015-constants/test/fixtures/options.json

@@ -1,3 +0,0 @@
-{
-  "plugins": ["transform-es2015-constants", "transform-es2015-block-scoping", "transform-es2015-destructuring"]
-}

packages/babel-preset-es2015/index.js

@@ -12,7 +12,7 @@ module.exports = {
     require("babel-plugin-transform-es2015-for-of"),
     require("babel-plugin-transform-es2015-sticky-regex"),
     require("babel-plugin-transform-es2015-unicode-regex"),
-    require("babel-plugin-transform-es2015-constants"),
+    require("babel-plugin-check-es2015-constants"),
     require("babel-plugin-transform-es2015-spread"),
     require("babel-plugin-transform-es2015-parameters"),
     require("babel-plugin-transform-es2015-destructuring"),

packages/babel-preset-es2015/package.json

@@ -20,7 +20,7 @@
     "babel-plugin-transform-es2015-for-of": "^6.1.4",
     "babel-plugin-transform-es2015-sticky-regex": "^6.1.4",
     "babel-plugin-transform-es2015-unicode-regex": "^6.1.4",
-    "babel-plugin-transform-es2015-constants": "^6.1.4",
+    "babel-plugin-check-es2015-constants": "^6.1.4",
     "babel-plugin-transform-es2015-spread": "^6.1.4",
     "babel-plugin-transform-es2015-parameters": "^6.1.4",
     "babel-plugin-transform-es2015-destructuring": "^6.1.4",

packages/babel-preset-es2015/test/fixtures/traceur/options.json

@@ -14,7 +14,7 @@
     "transform-es2015-for-of",
     "transform-es2015-sticky-regex",
     "transform-es2015-unicode-regex",
-    "transform-es2015-constants",
+    "check-es2015-constants",
     "transform-es2015-spread",
     "transform-es2015-parameters",
     "transform-es2015-destructuring",