fix(eslint-plugin): [efrt] flag default export w/allowExpressions (#831)

BREAKING: the rule didn't previously flag default exports with this option
typescript-eslint · Aug 10, 2019 · ebbcc01 · ebbcc01
1 parent 42b3013
commit ebbcc01
Show file tree

Hide file tree

Showing 3 changed files with 45 additions and 11 deletions.
diff --git a/packages/eslint-plugin/docs/rules/explicit-function-return-type.md b/packages/eslint-plugin/docs/rules/explicit-function-return-type.md
@@ -84,6 +84,10 @@ Examples of **incorrect** code for this rule with `{ allowExpressions: true }`:
 
 ```ts
 function test() {}
+
+const fn = () => {};
+
+export default () => {};
 ```
 
 Examples of **correct** code for this rule with `{ allowExpressions: true }`:
@@ -155,24 +159,20 @@ functionWithObjectArg({
 Examples of **incorrect** code for this rule with `{ allowHigherOrderFunctions: true }`:
 
 ```ts
-var arrowFn = (x: number) => (y: number) => x + y;
+var arrowFn = () => () => {};
 
-function fn(x: number) {
-  return function(y: number) {
-    return x + y;
-  };
+function fn() {
+  return function() {};
 }
 ```
 
 Examples of **correct** code for this rule with `{ allowHigherOrderFunctions: true }`:
 
 ```ts
-var arrowFn = (x: number) => (y: number): number => x + y;
+var arrowFn = () => (): void => {};
 
-function fn(x: number) {
-  return function(y: number): number {
-    return x + y;
-  };
+function fn() {
+  return function(): void {};
 }
 ```
 

diff --git a/packages/eslint-plugin/src/rules/explicit-function-return-type.ts b/packages/eslint-plugin/src/rules/explicit-function-return-type.ts
@@ -256,7 +256,8 @@ export default util.createRule<Options, MessageIds>({
         if (
           options.allowExpressions &&
           node.parent.type !== AST_NODE_TYPES.VariableDeclarator &&
-          node.parent.type !== AST_NODE_TYPES.MethodDefinition
+          node.parent.type !== AST_NODE_TYPES.MethodDefinition &&
+          node.parent.type !== AST_NODE_TYPES.ExportDefaultDeclaration
         ) {
           return;
         }

diff --git a/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts b/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts
@@ -90,6 +90,15 @@ class Test {
         },
       ],
     },
+    {
+      filename: 'test.ts',
+      code: `export default (): void => {}`,
+      options: [
+        {
+          allowExpressions: true,
+        },
+      ],
+    },
     {
       filename: 'test.ts',
       code: `
@@ -417,6 +426,30 @@ function test() {
         },
       ],
     },
+    {
+      filename: 'test.ts',
+      code: 'export default () => {};',
+      options: [{ allowExpressions: true }],
+      errors: [
+        {
+          messageId: 'missingReturnType',
+          line: 1,
+          column: 16,
+        },
+      ],
+    },
+    {
+      filename: 'test.ts',
+      code: 'export default function() {};',
+      options: [{ allowExpressions: true }],
+      errors: [
+        {
+          messageId: 'missingReturnType',
+          line: 1,
+          column: 16,
+        },
+      ],
+    },
     {
       filename: 'test.ts',
       code: "var arrowFn = () => 'test';",