Breaking: check unnamed default export in func-names (fixes #12194) (#…

…12195) * Breaking: check unnamed default export in func-names (fixes #12194) * docs: add that default export functions are checked * Revert "docs: add that default export functions are checked" This reverts commit 036ce53. * docs: add a note that export default functions needs name
eslint · Feb 17, 2020 · 6423e11 · 6423e11
1 parent 77df505
commit 6423e11
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Showing 3 changed files with 97 additions and 31 deletions.
diff --git a/docs/rules/func-names.md b/docs/rules/func-names.md
@@ -29,6 +29,8 @@ This rule has an object option:
 
 When a value for `generators` is not provided the behavior for generator functions falls back to the base option.
 
+Please note that `"always"` and `"as-needed"` require function expressions and function declarations in `export default` declarations to have a name.
+
 ### always
 
 Examples of **incorrect** code for this rule with the default `"always"` option:
@@ -45,6 +47,8 @@ const cat = {
 (function() {
     // ...
 }())
+
+export default function() {}
 ```
 
 Examples of **correct** code for this rule with the default `"always"` option:
@@ -61,6 +65,8 @@ const cat = {
 (function bar() {
     // ...
 }())
+
+export default function foo() {}
 ```
 
 ### as-needed
@@ -77,6 +83,8 @@ Foo.prototype.bar = function() {};
 (function() {
     // ...
 }())
+
+export default function() {}
 ```
 
 Examples of **correct** code for this rule with the `"as-needed"` option:
@@ -93,6 +101,8 @@ const cat = {
 (function bar() {
     // ...
 }())
+
+export default function foo() {}
 ```
 
 ### never

diff --git a/lib/rules/func-names.js b/lib/rules/func-names.js
@@ -119,7 +119,6 @@ module.exports = {
                 (parent.type === "VariableDeclarator" && parent.id.type === "Identifier" && parent.init === node) ||
                 (parent.type === "Property" && parent.value === node) ||
                 (parent.type === "AssignmentExpression" && parent.left.type === "Identifier" && parent.right === node) ||
-                (parent.type === "ExportDefaultDeclaration" && parent.declaration === node) ||
                 (parent.type === "AssignmentPattern" && parent.right === node);
         }
 
@@ -151,33 +150,41 @@ module.exports = {
             });
         }
 
-        return {
-            "FunctionExpression:exit"(node) {
+        /**
+         * The listener for function nodes.
+         * @param {ASTNode} node function node
+         * @returns {void}
+         */
+        function handleFunction(node) {
 
-                // Skip recursive functions.
-                const nameVar = context.getDeclaredVariables(node)[0];
+            // Skip recursive functions.
+            const nameVar = context.getDeclaredVariables(node)[0];
 
-                if (isFunctionName(nameVar) && nameVar.references.length > 0) {
-                    return;
-                }
+            if (isFunctionName(nameVar) && nameVar.references.length > 0) {
+                return;
+            }
 
-                const hasName = Boolean(node.id && node.id.name);
-                const config = getConfigForNode(node);
-
-                if (config === "never") {
-                    if (hasName) {
-                        reportUnexpectedNamedFunction(node);
-                    }
-                } else if (config === "as-needed") {
-                    if (!hasName && !hasInferredName(node)) {
-                        reportUnexpectedUnnamedFunction(node);
-                    }
-                } else {
-                    if (!hasName && !isObjectOrClassMethod(node)) {
-                        reportUnexpectedUnnamedFunction(node);
-                    }
+            const hasName = Boolean(node.id && node.id.name);
+            const config = getConfigForNode(node);
+
+            if (config === "never") {
+                if (hasName && node.type !== "FunctionDeclaration") {
+                    reportUnexpectedNamedFunction(node);
+                }
+            } else if (config === "as-needed") {
+                if (!hasName && !hasInferredName(node)) {
+                    reportUnexpectedUnnamedFunction(node);
+                }
+            } else {
+                if (!hasName && !isObjectOrClassMethod(node)) {
+                    reportUnexpectedUnnamedFunction(node);
                 }
             }
+        }
+
+        return {
+            "FunctionExpression:exit": handleFunction,
+            "ExportDefaultDeclaration > FunctionDeclaration": handleFunction
         };
     }
 };
diff --git a/tests/lib/rules/func-names.js b/tests/lib/rules/func-names.js
@@ -64,14 +64,6 @@ ruleTester.run("func-names", rule, {
             code: "(foo = function(){});",
             options: ["as-needed"]
         },
-        {
-            code: "export default (function(){});",
-            options: ["as-needed"],
-            parserOptions: {
-                ecmaVersion: 6,
-                sourceType: "module"
-            }
-        },
         {
             code: "({foo = function(){}} = {});",
             options: ["as-needed"],
@@ -127,6 +119,28 @@ ruleTester.run("func-names", rule, {
             parserOptions: { ecmaVersion: 6 }
         },
 
+        // export default
+        {
+            code: "export default function foo() {}",
+            options: ["always"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 }
+        },
+        {
+            code: "export default function foo() {}",
+            options: ["as-needed"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 }
+        },
+        {
+            code: "export default function foo() {}",
+            options: ["never"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 }
+        },
+        {
+            code: "export default function() {}",
+            options: ["never"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 }
+        },
+
         // generators
         {
             code: "var foo = bar(function *baz() {});",
@@ -415,6 +429,41 @@ ruleTester.run("func-names", rule, {
             }]
         },
 
+        // export default
+        {
+            code: "export default function() {}",
+            options: ["always"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 },
+            errors: [{
+                messageId: "unnamed",
+                type: "FunctionDeclaration",
+                column: 16,
+                endColumn: 24
+            }]
+        },
+        {
+            code: "export default function() {}",
+            options: ["as-needed"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 },
+            errors: [{
+                messageId: "unnamed",
+                type: "FunctionDeclaration",
+                column: 16,
+                endColumn: 24
+            }]
+        },
+        {
+            code: "export default (function(){});",
+            options: ["as-needed"],
+            parserOptions: { sourceType: "module", ecmaVersion: 6 },
+            errors: [{
+                messageId: "unnamed",
+                type: "FunctionExpression",
+                column: 17,
+                endColumn: 25
+            }]
+        },
+
         // generators
         {
             code: "var foo = bar(function *() {});",