Fixed false positives inside the ternary operator in no-async-in-computed-properties (#962)

* Fixed false positives inside the ternary operator in `no-async-in-computed-properties`

* Add testcase

Author: ota-meshi

Diff for: lib/rules/no-async-in-computed-properties.js

@@ -73,7 +73,7 @@ module.exports = {
 
   create (context) {
     const forbiddenNodes = []
-    const allowedScopes = []
+    let scopeStack = { upper: null, body: null }
 
     const expressionTypes = {
       promise: 'asynchronous action',
@@ -87,65 +87,54 @@ module.exports = {
       if (node.async) {
         forbiddenNodes.push({
           node: node,
-          type: 'async'
+          type: 'async',
+          targetBody: node.body
         })
-      } else if (node.parent.type === 'ReturnStatement') {
-        allowedScopes.push(node)
       }
+
+      scopeStack = { upper: scopeStack, body: node.body }
     }
 
+    function onFunctionExit () {
+      scopeStack = scopeStack.upper
+    }
     return Object.assign({},
       {
-        FunctionDeclaration: onFunctionEnter,
-
-        FunctionExpression: onFunctionEnter,
-
-        ArrowFunctionExpression: onFunctionEnter,
+        ':function': onFunctionEnter,
+        ':function:exit': onFunctionExit,
 
         NewExpression (node) {
           if (node.callee.name === 'Promise') {
             forbiddenNodes.push({
               node: node,
-              type: 'new'
+              type: 'new',
+              targetBody: scopeStack.body
             })
-          } else if (node.parent.type === 'ReturnStatement') {
-            allowedScopes.push(node)
           }
         },
 
         CallExpression (node) {
           if (isPromise(node)) {
             forbiddenNodes.push({
               node: node,
-              type: 'promise'
+              type: 'promise',
+              targetBody: scopeStack.body
             })
           } else if (isTimedFunction(node)) {
             forbiddenNodes.push({
               node: node,
-              type: 'timed'
+              type: 'timed',
+              targetBody: scopeStack.body
             })
-          } else if (node.parent.type === 'ReturnStatement') {
-            allowedScopes.push(node)
           }
         },
 
         AwaitExpression (node) {
           forbiddenNodes.push({
             node: node,
-            type: 'await'
+            type: 'await',
+            targetBody: scopeStack.body
           })
-        },
-
-        'ReturnStatement' (node) {
-          if (
-            node.argument &&
-            (
-              node.argument.type === 'ObjectExpression' ||
-              node.argument.type === 'ArrayExpression'
-            )
-          ) {
-            allowedScopes.push(node.argument)
-          }
         }
       },
       utils.executeOnVue(context, (obj) => {
@@ -157,10 +146,7 @@ module.exports = {
               cp.value &&
               el.node.loc.start.line >= cp.value.loc.start.line &&
               el.node.loc.end.line <= cp.value.loc.end.line &&
-              !allowedScopes.some(scope =>
-                scope.range[0] < el.node.range[0] &&
-                scope.range[1] > el.node.range[1]
-              )
+              el.targetBody === cp.value
             ) {
               context.report({
                 node: el.node,

Diff for: tests/lib/rules/no-async-in-computed-properties.js

@@ -181,6 +181,49 @@ ruleTester.run('no-async-in-computed-properties', rule, {
         }
       `,
       parserOptions
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+            computed: {
+                foo() {
+                    return this.bar
+                      ? {
+                          baz:() => Promise.resolve(1)
+                        }
+                      : {}
+                }
+            }
+        }
+      `,
+      parserOptions
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+            computed: {
+                foo() {
+                    return this.bar ? () => Promise.resolve(1) : null
+                }
+            }
+        }
+      `,
+      parserOptions
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+            computed: {
+                foo() {
+                    return this.bar ? async () => 1 : null
+                }
+            }
+        }
+      `,
+      parserOptions
     }
   ],