Fix jsx-uses-react for ESLint 0.17.0

Author: yannickcr

docs/rules/jsx-uses-vars.md

@@ -0,0 +1,25 @@
+# Prevent variables used in JSX to be incorrectly marked as unused (jsx-uses-vars)
+
+Since 0.17.0 the ESLint `no-unused-vars` rule does not detect variables used in JSX ([See details](eslint.org/blog/2015/03/eslint-0.17.0-released/#changes-to-jsx/react-handling)). This rules will find varaibles used in JSX and mark them as used.
+
+This rule has no effect if the `no-unused-vars` rule is not enabled.
+
+## Rule Details
+
+The following patterns are considered warnings:
+
+```js
+var Hello = require('./Hello');
+```
+
+The following patterns are not considered warnings:
+
+```js
+var Hello = require('./Hello');
+
+<Hello name="John" />;
+```
+
+## When Not To Use It
+
+If you are not using JSX or if you do not use the `no-unused-vars` rule then you can disable this rule.

lib/rules/jsx-uses-react.js

@@ -10,34 +10,14 @@
 
 module.exports = function(context) {
 
-  function flagReactAsUsedInJSX() {
-    var scope = context.getScope(),
-      variables = scope.variables,
-      i,
-      len;
-
-    while (scope.type !== 'global') {
-      scope = scope.upper;
-      variables = [].concat.apply(scope.variables, variables);
-    }
-
-    // mark first React found with the same special flag used by no-unused-vars
-    for (i = 0, len = variables.length; i < len; i++) {
-      if (variables[i].name === 'React') {
-        variables[i].eslintJSXUsed = true;
-        return;
-      }
-    }
-  }
-
   // --------------------------------------------------------------------------
   // Public
   // --------------------------------------------------------------------------
 
   return {
 
     'JSXOpeningElement': function() {
-      flagReactAsUsedInJSX();
+      context.markVariableAsUsed('React');
     }
   };
 

package.json

@@ -24,7 +24,7 @@
   "bugs": "https://github.com/yannickcr/eslint-plugin-react/issues",
   "devDependencies": {
     "coveralls": "2.11.2",
-    "eslint": "0.15.0",
+    "eslint": "0.17.0",
     "eslint-tester": "0.6.0",
     "istanbul": "0.3.6",
     "mocha": "2.1.0"

tests/lib/rules/jsx-uses-react.js

@@ -20,7 +20,6 @@ var eslintTester = new ESLintTester(eslint);
 eslint.defineRule('jsx-uses-react', require('../../../lib/rules/jsx-uses-react'));
 eslintTester.addRuleTest('node_modules/eslint/lib/rules/no-unused-vars', {
     valid: [
-        {code: '/*eslint jsx-uses-react:1*/ var App, React; <App />;', ecmaFeatures: {jsx: true}},
         {code: '/*eslint jsx-uses-react:1*/ var React; <div />;', ecmaFeatures: {jsx: true}},
         {code: '/*eslint jsx-uses-react:1*/ var React; (function () { <div /> })();', ecmaFeatures: {jsx: true}}
     ],