feat(no-standalone-expect): support additionalTestBlockFunctions

Author: G-Rath

docs/rules/no-standalone-expect.md

@@ -64,6 +64,36 @@ describe('a test', () => {
 thought the `expect` will not execute. Rely on a rule like no-unused-vars for
 this case.
 
+### Options
+
+#### `additionalTestBlockFunctions`
+
+This array can be used to specify the names of functions that should also be
+treated as test blocks:
+
+```json
+{
+  "rules": {
+    "jest/no-standalone-expect": [
+      "error",
+      { "additionalTestBlockFunctions": ["each.test"] }
+    ]
+  }
+}
+```
+
+The following is _correct_ when using the above configuration:
+
+```js
+each([
+  [1, 1, 2],
+  [1, 2, 3],
+  [2, 1, 3],
+]).test('returns the result of adding %d to %d', (a, b, expected) => {
+  expect(a + b).toBe(expected);
+});
+```
+
 ## When Not To Use It
 
 Don't use this rule on non-jest test files.

src/rules/__tests__/no-standalone-expect.test.ts

@@ -34,8 +34,86 @@ ruleTester.run('no-standalone-expect', rule, {
     'it.only("an only", value => { expect(value).toBe(true); });',
     'it.concurrent("an concurrent", value => { expect(value).toBe(true); });',
     'describe.each([1, true])("trues", value => { it("an it", () => expect(value).toBe(true) ); });',
+    {
+      code: `
+        describe('scenario', () => {
+          const t = Math.random() ? it.only : it;
+          t('testing', () => expect(true));
+        });
+      `,
+      options: [{ additionalTestBlockFunctions: ['t'] }],
+    },
+    {
+      code: `
+        each([
+          [1, 1, 2],
+          [1, 2, 3],
+          [2, 1, 3],
+        ]).test('returns the result of adding %d to %d', (a, b, expected) => {
+          expect(a + b).toBe(expected);
+        });
+      `,
+      options: [{ additionalTestBlockFunctions: ['each.test'] }],
+    },
   ],
   invalid: [
+    {
+      code: `
+        describe('scenario', () => {
+          const t = Math.random() ? it.only : it;
+          t('testing', () => expect(true));
+        });
+      `,
+      errors: [{ endColumn: 42, column: 30, messageId: 'unexpectedExpect' }],
+    },
+    {
+      code: `
+        describe('scenario', () => {
+          const t = Math.random() ? it.only : it;
+          t('testing', () => expect(true));
+        });
+      `,
+      options: [{ additionalTestBlockFunctions: undefined }],
+      errors: [{ endColumn: 42, column: 30, messageId: 'unexpectedExpect' }],
+    },
+    {
+      code: `
+        each([
+          [1, 1, 2],
+          [1, 2, 3],
+          [2, 1, 3],
+        ]).test('returns the result of adding %d to %d', (a, b, expected) => {
+          expect(a + b).toBe(expected);
+        });
+      `,
+      errors: [{ endColumn: 24, column: 11, messageId: 'unexpectedExpect' }],
+    },
+    {
+      code: `
+        each([
+          [1, 1, 2],
+          [1, 2, 3],
+          [2, 1, 3],
+        ]).test('returns the result of adding %d to %d', (a, b, expected) => {
+          expect(a + b).toBe(expected);
+        });
+      `,
+      options: [{ additionalTestBlockFunctions: ['each'] }],
+      errors: [{ endColumn: 24, column: 11, messageId: 'unexpectedExpect' }],
+    },
+    {
+      code: `
+        each([
+          [1, 1, 2],
+          [1, 2, 3],
+          [2, 1, 3],
+        ]).test('returns the result of adding %d to %d', (a, b, expected) => {
+          expect(a + b).toBe(expected);
+        });
+      `,
+      options: [{ additionalTestBlockFunctions: ['test'] }],
+      errors: [{ endColumn: 24, column: 11, messageId: 'unexpectedExpect' }],
+    },
     {
       code: 'describe("a test", () => { expect(1).toBe(1); });',
       errors: [{ endColumn: 37, column: 28, messageId: 'unexpectedExpect' }],

src/rules/no-standalone-expect.ts

@@ -6,6 +6,7 @@ import {
   DescribeAlias,
   TestCaseName,
   createRule,
+  getNodeName,
   isDescribe,
   isExpectCall,
   isFunction,
@@ -56,7 +57,10 @@ type callStackEntry =
   | 'arrowFunc'
   | 'template';
 
-export default createRule({
+export default createRule<
+  [{ additionalTestBlockFunctions: string[] }],
+  'unexpectedExpect'
+>({
   name: __filename,
   meta: {
     docs: {
@@ -68,12 +72,27 @@ export default createRule({
       unexpectedExpect: 'Expect must be inside of a test block.',
     },
     type: 'suggestion',
-    schema: [],
+    schema: [
+      {
+        properties: {
+          additionalTestBlockFunctions: {
+            type: 'array',
+            items: { type: 'string' },
+          },
+        },
+        additionalProperties: false,
+      },
+    ],
   },
-  defaultOptions: [],
-  create(context) {
+  defaultOptions: [{ additionalTestBlockFunctions: [] }],
+  create(context, [{ additionalTestBlockFunctions = [] }]) {
     const callStack: callStackEntry[] = [];
 
+    const isCustomTestBlockFunction = (
+      node: TSESTree.CallExpression,
+    ): boolean =>
+      additionalTestBlockFunctions.includes(getNodeName(node) || '');
+
     return {
       CallExpression(node) {
         if (isExpectCall(node)) {
@@ -83,7 +102,7 @@ export default createRule({
           }
           return;
         }
-        if (isTestCase(node)) {
+        if (isTestCase(node) || isCustomTestBlockFunction(node)) {
           callStack.push(TestCaseName.test);
         }
         if (node.callee.type === AST_NODE_TYPES.TaggedTemplateExpression) {
@@ -92,8 +111,9 @@ export default createRule({
       },
       'CallExpression:exit'(node: TSESTree.CallExpression) {
         const top = callStack[callStack.length - 1];
+
         if (
-          (((isTestCase(node) &&
+          ((((isTestCase(node) || isCustomTestBlockFunction(node)) &&
             node.callee.type !== AST_NODE_TYPES.MemberExpression) ||
             isEach(node)) &&
             top === TestCaseName.test) ||