Update: fix false negative in no-use-before-define (fixes #10227) (#1…

…0396) * Update: fix false negative in no-use-before-define (fixes #10227) * reorder tests
eslint · Jun 9, 2018 · dc4075e · dc4075e
1 parent 3721841
commit dc4075e
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Showing 2 changed files with 53 additions and 39 deletions.
diff --git a/lib/rules/no-use-before-define.js b/lib/rules/no-use-before-define.js
@@ -219,49 +219,14 @@ module.exports = {
                     data: reference.identifier
                 });
             });
-        }
 
-        /**
-         * Validates variables inside of a node's scope.
-         * @param {ASTNode} node The node to check.
-         * @returns {void}
-         * @private
-         */
-        function findVariables() {
-            const scope = context.getScope();
-
-            findVariablesInScope(scope);
+            scope.childScopes.forEach(findVariablesInScope);
         }
 
-        const ruleDefinition = {
-            "Program:exit"(node) {
-                const scope = context.getScope(),
-                    ecmaFeatures = context.parserOptions.ecmaFeatures || {};
-
-                findVariablesInScope(scope);
-
-                // both Node.js and Modules have an extra scope
-                if (ecmaFeatures.globalReturn || node.sourceType === "module") {
-                    findVariablesInScope(scope.childScopes[0]);
-                }
+        return {
+            Program() {
+                findVariablesInScope(context.getScope());
             }
         };
-
-        if (context.parserOptions.ecmaVersion >= 6) {
-            ruleDefinition["BlockStatement:exit"] =
-                ruleDefinition["SwitchStatement:exit"] = findVariables;
-
-            ruleDefinition["ArrowFunctionExpression:exit"] = function(node) {
-                if (node.body.type !== "BlockStatement") {
-                    findVariables();
-                }
-            };
-        } else {
-            ruleDefinition["FunctionExpression:exit"] =
-                ruleDefinition["FunctionDeclaration:exit"] =
-                ruleDefinition["ArrowFunctionExpression:exit"] = findVariables;
-        }
-
-        return ruleDefinition;
     }
 };
diff --git a/tests/lib/rules/no-use-before-define.js b/tests/lib/rules/no-use-before-define.js
@@ -113,6 +113,55 @@ ruleTester.run("no-use-before-define", rule, {
             code: "foo; var foo;",
             options: [{ variables: false }],
             errors: [{ message: "'foo' was used before it was defined.", type: "Identifier" }]
+        },
+
+        // https://github.com/eslint/eslint/issues/10227
+        {
+            code: "for (let x = x;;); let x = 0",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+        {
+            code: "for (let x in xs); let xs = []",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'xs' was used before it was defined."]
+        },
+        {
+            code: "for (let x of xs); let xs = []",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'xs' was used before it was defined."]
+        },
+        {
+            code: "try {} catch ({message = x}) {} let x = ''",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+        {
+            code: "with (obj) x; let x = {}",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+
+        // WithStatements.
+        {
+            code: "with (x); let x = {}",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+        {
+            code: "with (obj) { x } let x = {}",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+        {
+            code: "with (obj) { if (a) { x } } let x = {}",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
+        },
+        {
+            code: "with (obj) { (() => { if (a) { x } })() } let x = {}",
+            parserOptions: { ecmaVersion: 2015 },
+            errors: ["'x' was used before it was defined."]
         }
     ]
 });