Fix ESLint 6.2.0 + babel-eslint + no-unused-vars false positive with for-in loop

.eslintrc.js

@@ -1,20 +1,24 @@
 "use strict";
 
+const config = require("eslint-config-babel");
+
 module.exports = {
   root: true,
-  extends: "babel",
-  plugins: ["prettier"],
-  rules: {
+  parser: "./lib",
+  extends: config.extends,
+  plugins: config.plugins.concat(["prettier"]),
+  rules: Object.assign(config.rules, {
     "max-len": "off",
     strict: "error",
     "prettier/prettier": "error",
-  },
-  env: {
+  }),
+  env: Object.assign(config.env, {
     node: true,
-  },
-  parserOptions: {
+  }),
+  parserOptions: Object.assign(config.parserOptions, {
     sourceType: "script",
-  },
+  }),
+  globals: config.globals,
   overrides: [
     {
       files: ["test/**/*"],

.prettierrc

@@ -1,3 +1,3 @@
 {
-    "trailingComma": "es5"
-  }
+  "trailingComma": "es5"
+}

babel.config.js

@@ -0,0 +1,21 @@
+"use strict";
+
+module.exports = {
+  presets: [
+    ["@babel/preset-env", { forceAllTransforms: true }],
+    ["@babel/preset-flow", { all: true }],
+    "@babel/preset-react",
+  ],
+  plugins: [
+    "@babel/plugin-syntax-dynamic-import",
+    "@babel/plugin-syntax-import-meta",
+    "@babel/plugin-syntax-export-default-from",
+    "@babel/plugin-proposal-class-properties",
+    "@babel/plugin-proposal-nullish-coalescing-operator",
+    "@babel/plugin-proposal-optional-chaining",
+    "@babel/plugin-syntax-numeric-separator",
+    "@babel/plugin-syntax-export-namespace-from",
+    ["@babel/plugin-proposal-decorators", { decoratorsBeforeExport: false }],
+    ["@babel/plugin-proposal-pipeline-operator", { proposal: "minimal" }],
+  ],
+};

lib/babylon-to-espree/convertAST.js

@@ -47,26 +47,6 @@ const astTransformVisitor = {
   exit(path) {
     const node = path.node;
 
-    if (path.isJSXText()) {
-      node.type = "Literal";
-    }
-
-    if (
-      path.isRestElement() &&
-      path.parent &&
-      path.parent.type === "ObjectPattern"
-    ) {
-      node.type = "ExperimentalRestProperty";
-    }
-
-    if (
-      path.isSpreadElement() &&
-      path.parent &&
-      path.parent.type === "ObjectExpression"
-    ) {
-      node.type = "ExperimentalSpreadProperty";
-    }
-
     if (path.isTypeParameter()) {
       node.type = "Identifier";
       node.typeAnnotation = node.bound;

package.json

@@ -17,7 +17,6 @@
     "test-only": "cd test && mocha specs && cd -",
     "lint": "eslint .",
     "lint-fix": "npm run lint -- --fix",
-    "precommit": "lint-staged",
     "preversion": "npm test",
     "changelog": "git log `git describe --tags --abbrev=0`..HEAD --pretty=format:' * %s (%an)' | grep -v 'Merge pull request'"
   },
@@ -33,42 +32,46 @@
     "eslint": ">= 4.12.1"
   },
   "dependencies": {
-    "eslint-scope": "3.7.1",
-    "eslint-visitor-keys": "^1.0.0",
-    "semver": "^5.6.0"
+    "eslint-scope": "^5.0.0",
+    "eslint-visitor-keys": "^1.1.0",
+    "semver": "^6.3.0"
   },
   "devDependencies": {
-    "@babel/core": "^7.2.0",
-    "@babel/plugin-proposal-class-properties": "^7.1.0",
-    "@babel/plugin-proposal-decorators": "^7.1.2",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.0.0",
-    "@babel/plugin-proposal-optional-chaining": "^7.0.0",
-    "@babel/plugin-proposal-pipeline-operator": "^7.0.0",
-    "@babel/plugin-syntax-dynamic-import": "^7.0.0",
-    "@babel/plugin-syntax-export-default-from": "^7.0.0",
-    "@babel/plugin-syntax-export-namespace-from": "^7.0.0",
-    "@babel/plugin-syntax-import-meta": "^7.0.0",
-    "@babel/plugin-syntax-numeric-separator": "^7.0.0",
-    "@babel/preset-env": "^7.1.5",
+    "@babel/core": "^7.5.5",
+    "@babel/plugin-proposal-class-properties": "^7.5.5",
+    "@babel/plugin-proposal-decorators": "^7.4.4",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.4.4",
+    "@babel/plugin-proposal-optional-chaining": "^7.2.0",
+    "@babel/plugin-proposal-pipeline-operator": "^7.5.0",
+    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
+    "@babel/plugin-syntax-export-default-from": "^7.2.0",
+    "@babel/plugin-syntax-export-namespace-from": "^7.2.0",
+    "@babel/plugin-syntax-import-meta": "^7.2.0",
+    "@babel/plugin-syntax-numeric-separator": "^7.2.0",
+    "@babel/preset-env": "^7.5.5",
     "@babel/preset-flow": "^7.0.0",
     "@babel/preset-react": "^7.0.0",
-    "babel-eslint": "^10.0.2",
     "dedent": "^0.7.0",
-    "eslint": "^6.0.1",
+    "eslint": "^6.2.0",
     "eslint-config-babel": "^9.0.0",
-    "eslint-plugin-flowtype": "^3.11.1",
-    "eslint-plugin-import": "^2.14.0",
+    "eslint-plugin-flowtype": "^4.2.0",
+    "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-prettier": "^3.1.0",
-    "espree": "^3.5.2",
-    "husky": "^1.0.0-rc.13",
-    "lint-staged": "^7.2.2",
-    "mocha": "^6.1.4",
-    "prettier": "^1.4.4"
+    "espree": "^6.1.0",
+    "husky": "^3.0.4",
+    "lint-staged": "^9.2.3",
+    "mocha": "^6.2.0",
+    "prettier": "^1.18.2"
   },
   "lint-staged": {
     "*.js": [
       "eslint --format=codeframe --fix",
       "git add"
     ]
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
   }
 }

test/babel.config.js

@@ -1,21 +1,5 @@
 "use strict";
 
-module.exports = {
-  presets: [
-    ["@babel/preset-env", { forceAllTransforms: true }],
-    ["@babel/preset-flow", { all: true }],
-    "@babel/preset-react",
-  ],
-  plugins: [
-    "@babel/plugin-syntax-dynamic-import",
-    "@babel/plugin-syntax-import-meta",
-    "@babel/plugin-syntax-export-default-from",
-    "@babel/plugin-proposal-class-properties",
-    "@babel/plugin-proposal-nullish-coalescing-operator",
-    "@babel/plugin-proposal-optional-chaining",
-    "@babel/plugin-syntax-numeric-separator",
-    "@babel/plugin-syntax-export-namespace-from",
-    ["@babel/plugin-proposal-decorators", { decoratorsBeforeExport: false }],
-    ["@babel/plugin-proposal-pipeline-operator", { proposal: "minimal" }],
-  ],
-};
+const config = require("../babel.config.js");
+
+module.exports = config;

test/specs/babel-eslint.js

@@ -451,7 +451,9 @@ describe("babylon-to-espree", () => {
     });
 
     it("super outside method", () => {
-      parseAndAssertSame("function F() { super(); }");
+      assert.throws(() => {
+        parseAndAssertSame("function F() { super(); }");
+      }, /SyntaxError: 'super' keyword outside a method/);
     });
 
     it("StringLiteral", () => {

test/specs/integration.js

@@ -238,3 +238,30 @@ describe("https://github.com/babel/babel-eslint/issues/558", () => {
     ]);
   });
 });
+
+describe("no-unused-vars", () => {
+  const ruleId = "no-unused-vars";
+  const eslintOpts = Object.assign({}, baseEslintOpts, {
+    rules: {},
+  });
+  eslintOpts.rules[ruleId] = [errorLevel, "never"];
+
+  it("should not detect false positives inside for loop", () => {
+    const src =
+      "const nodeList = []; const visit = () => {}; for (const node of nodeList) { visit(node); }";
+
+    const report = eslint.linter.verify(src, eslintOpts);
+
+    assert(report.length === 0);
+  });
+
+  it("should detect unused var inside for loop", () => {
+    const src =
+      "const nodeList = []; const visit = () => {}; for (const node of nodeList) { visit(); }";
+
+    const report = eslint.linter.verify(src, eslintOpts);
+
+    assert(report.length === 1);
+    assert(report[0].ruleId === ruleId);
+  });
+});