Fix false positives for arrow function in return-in-emits-validator rule (#1138)

Author: ota-meshi

lib/rules/return-in-emits-validator.js

@@ -74,6 +74,14 @@ module.exports = {
           },
           ':function' (node) {
             scopeStack = { upper: scopeStack, functionNode: node, hasReturnValue: false, possibleOfReturnTrue: false }
+
+            if (node.type === 'ArrowFunctionExpression' && node.expression) {
+              scopeStack.hasReturnValue = true
+
+              if (!isFalsy(node.body)) {
+                scopeStack.possibleOfReturnTrue = true
+              }
+            }
           },
           ReturnStatement (node) {
             if (node.argument) {

tests/lib/rules/return-in-emits-validator.js

@@ -38,6 +38,7 @@ ruleTester.run('return-in-emits-validator', rule, {
             baz: (e) => {
               return e
             },
+            baz2: (e) => e,
             qux () {
               if (foo) {
                 return true
@@ -174,6 +175,22 @@ ruleTester.run('return-in-emits-validator', rule, {
         line: 5
       }]
     },
+    {
+      filename: 'test.vue',
+      code: `
+        <script>
+        export default {
+          emits: {
+            foo: () => false
+          }
+        }
+        </script>
+      `,
+      errors: [{
+        message: 'Expected to return a true value in "foo" emits validator.',
+        line: 5
+      }]
+    },
     {
       filename: 'test.vue',
       code: `