fix(prefer-expect-assertions): report on concise arrow functions with expect call (#1225)

Author: G-Rath

src/rules/__tests__/prefer-expect-assertions.test.ts

@@ -115,6 +115,28 @@ ruleTester.run('prefer-expect-assertions', rule, {
         },
       ],
     },
+    {
+      code: "it('resolves', () => expect(staged()).toBe(true));",
+      errors: [
+        {
+          messageId: 'haveExpectAssertions',
+          column: 1,
+          line: 1,
+          suggestions: null,
+        },
+      ],
+    },
+    {
+      code: "it('resolves', async () => expect(await staged()).toBe(true));",
+      errors: [
+        {
+          messageId: 'haveExpectAssertions',
+          column: 1,
+          line: 1,
+          suggestions: null,
+        },
+      ],
+    },
     {
       code: 'it("it1", () => {})',
       errors: [

src/rules/prefer-expect-assertions.ts

@@ -16,6 +16,12 @@ const isFirstStatement = (node: TSESTree.CallExpression): boolean => {
       return parent.parent.body[0] === parent;
     }
 
+    // if we've hit an arrow function, then it must have a single expression
+    // as its body, as otherwise we would have hit the block statement already
+    if (parent.parent?.type === AST_NODE_TYPES.ArrowFunctionExpression) {
+      return true;
+    }
+
     parent = parent.parent;
   }
 
@@ -52,11 +58,6 @@ type MessageIds =
   | 'suggestAddingAssertions'
   | 'suggestRemovingExtraArguments';
 
-// const suggestions: Array<[MessageIds, string]> = [
-//   ['suggestAddingHasAssertions', 'expect.hasAssertions();'],
-//   ['suggestAddingAssertions', 'expect.assertions();'],
-// ];
-
 export default createRule<[RuleOptions], MessageIds>({
   name: __filename,
   meta: {