feat: support allowedPrefixes option in lowercase-name rule (#419)

Author: G-Rath

docs/rules/lowercase-name.md

@@ -70,3 +70,19 @@ Example of **correct** code for the `{ "ignore": ["it"] }` option:
 
 it('Uppercase description');
 ```
+
+### `allow`
+
+This array option whitelists prefixes that titles can start with with capitals.
+This can be useful when writing tests for api endpoints, where you'd like to
+prefix with the HTTP method.
+
+By default, nothing is allowed (the equivalent of `{ "allow": [] }`).
+
+Example of **correct** code for the `{ "allow": ["GET"] }` option:
+
+```js
+/* eslint jest/lowercase-name: ["error", { "allow": ["GET"] }] */
+
+describe('GET /live');
+```

src/rules/__tests__/lowercase-name.test.ts

@@ -46,6 +46,10 @@ ruleTester.run('lowercase-name', rule, {
     'describe(``)',
     'describe("")',
     'describe(42)',
+    {
+      code: 'describe(42)',
+      options: [{ ignore: undefined, allowedPrefixes: undefined }],
+    },
   ],
 
   invalid: [
@@ -225,3 +229,21 @@ ruleTester.run('lowercase-name with ignore=it', rule, {
   ],
   invalid: [],
 });
+
+ruleTester.run('lowercase-name with allowedPrefixes', rule, {
+  valid: [
+    {
+      code: "it('GET /live', function () {})",
+      options: [{ allowedPrefixes: ['GET'] }],
+    },
+    {
+      code: 'it("POST /live", function () {})',
+      options: [{ allowedPrefixes: ['GET', 'POST'] }],
+    },
+    {
+      code: 'it(`PATCH /live`, function () {})',
+      options: [{ allowedPrefixes: ['GET', 'PATCH'] }],
+    },
+  ],
+  invalid: [],
+});

src/rules/lowercase-name.ts

@@ -54,9 +54,13 @@ const testDescription = (argument: ArgumentLiteral): string | null => {
 
 const jestFunctionName = (
   node: CallExpressionWithCorrectCalleeAndArguments,
+  allowedPrefixes: readonly string[],
 ) => {
   const description = testDescription(node.arguments[0]);
-  if (description === null) {
+  if (
+    description === null ||
+    allowedPrefixes.some(name => description.startsWith(name))
+  ) {
     return null;
   }
 
@@ -73,7 +77,15 @@ const jestFunctionName = (
   return null;
 };
 
-export default createRule({
+export default createRule<
+  [
+    Partial<{
+      ignore: readonly JestFunctionName[];
+      allowedPrefixes: readonly string[];
+    }>,
+  ],
+  'unexpectedLowercase'
+>({
   name: __filename,
   meta: {
     type: 'suggestion',
@@ -96,19 +108,24 @@ export default createRule({
             items: { enum: ['describe', 'test', 'it'] },
             additionalItems: false,
           },
+          allowedPrefixes: {
+            type: 'array',
+            items: { type: 'string' },
+            additionalItems: false,
+          },
         },
         additionalProperties: false,
       },
     ],
   } as const,
-  defaultOptions: [{ ignore: [] } as { ignore: readonly JestFunctionName[] }],
-  create(context, [{ ignore }]) {
+  defaultOptions: [{ ignore: [], allowedPrefixes: [] }],
+  create(context, [{ ignore = [], allowedPrefixes = [] }]) {
     return {
       CallExpression(node) {
         if (!isJestFunctionWithLiteralArg(node)) {
           return;
         }
-        const erroneousMethod = jestFunctionName(node);
+        const erroneousMethod = jestFunctionName(node, allowedPrefixes);
 
         if (erroneousMethod && !ignore.includes(node.callee.name)) {
           context.report({