refactor: add fixer

Author: brettz9

README.md

@@ -115,7 +115,7 @@ or start with the recommended rule set:
 | [param-names](docs/rules/param-names.md)                             | Enforce consistent param names and ordering when creating new promises.                    | ✅  |     |     |     |
 | [prefer-await-to-callbacks](docs/rules/prefer-await-to-callbacks.md) | Prefer `async`/`await` to the callback pattern.                                            |     |     |     |     |
 | [prefer-await-to-then](docs/rules/prefer-await-to-then.md)           | Prefer `await` to `then()`/`catch()`/`finally()` for reading Promise values.               |     |     |     |     |
-| [prefer-catch](docs/rules/prefer-catch.md)                           | Prefer `catch` to `then(a, b)`/`then(null, b)` for handling errors.                        |     |     |     |     |
+| [prefer-catch](docs/rules/prefer-catch.md)                           | Prefer `catch` to `then(a, b)`/`then(null, b)` for handling errors.                        |     |     |     | 🔧  |
 | [spec-only](docs/rules/spec-only.md)                                 | Disallow use of non-standard Promise static methods.                                       |     |     |     |     |
 | [valid-params](docs/rules/valid-params.md)                           | Enforces the proper number of arguments are passed to Promise functions.                   |     | ✅  |     |     |
 

__tests__/prefer-catch.js

@@ -26,22 +26,40 @@ ruleTester.run('prefer-catch', rule, {
     {
       code: 'hey.then(fn1, fn2)',
       errors: [{ message }],
+      output: 'hey.catch(fn2).then(fn1)',
+    },
+    {
+      code: 'hey.then(fn1, (fn2))',
+      errors: [{ message }],
+      output: 'hey.catch(fn2).then(fn1)',
     },
     {
       code: 'hey.then(null, fn2)',
       errors: [{ message }],
+      output: 'hey.catch(fn2)',
+    },
+    {
+      code: 'hey.then(undefined, fn2)',
+      errors: [{ message }],
+      output: 'hey.catch(fn2)',
     },
     {
       code: 'function foo() { hey.then(x => {}, () => {}) }',
       errors: [{ message }],
+      output: 'function foo() { hey.catch(() => {}).then(x => {}) }',
     },
     {
       code: `
         function foo() {
-          hey.then(function() { }, function() {}).then(fn1, fn2)
+          hey.then(function a() { }, function b() {}).then(fn1, fn2)
         }
       `,
       errors: [{ message }, { message }],
+      output: `
+        function foo() {
+          hey.catch(function b() {}).then(function a() { }).catch(fn2).then(fn1)
+        }
+      `,
     },
   ],
 })

docs/rules/prefer-catch.md

@@ -1,5 +1,8 @@
 # Prefer `catch` to `then(a, b)`/`then(null, b)` for handling errors (`promise/prefer-catch`)
 
+🔧 This rule is automatically fixable by the
+[`--fix` CLI option](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix).
+
 <!-- end auto-generated rule header -->
 
 A `then` call with two arguments can make it more difficult to recognize that a