feat(eslint-plugin): [await-thenable] added suggestion fixer (#7437)

* feat(eslint-plugin): added suggestion fixer to await-thenable * Aha, getFirstToken
typescript-eslint · Sep 8, 2023 · b284370 · b284370
1 parent 4908905
commit b284370
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Showing 2 changed files with 149 additions and 53 deletions.
diff --git a/packages/eslint-plugin/src/rules/await-thenable.ts b/packages/eslint-plugin/src/rules/await-thenable.ts
@@ -1,3 +1,4 @@
+import type { TSESLint } from '@typescript-eslint/utils';
 import * as tsutils from 'ts-api-utils';
 
 import * as util from '../util';
@@ -10,8 +11,10 @@ export default util.createRule({
       recommended: 'recommended',
       requiresTypeChecking: true,
     },
+    hasSuggestions: true,
     messages: {
       await: 'Unexpected `await` of a non-Promise (non-"Thenable") value.',
+      removeAwait: 'Remove unnecessary `await`.',
     },
     schema: [],
     type: 'problem',
@@ -35,6 +38,23 @@ export default util.createRule({
           context.report({
             messageId: 'await',
             node,
+            suggest: [
+              {
+                messageId: 'removeAwait',
+                fix(fixer): TSESLint.RuleFix {
+                  const sourceCode = context.getSourceCode();
+                  const awaitKeyword = util.nullThrows(
+                    sourceCode.getFirstToken(node, util.isAwaitKeyword),
+                    util.NullThrowsReasons.MissingToken(
+                      'await',
+                      'await expression',
+                    ),
+                  );
+
+                  return fixer.remove(awaitKeyword);
+                },
+              },
+            ],
           });
         }
       },

diff --git a/packages/eslint-plugin/tests/rules/await-thenable.test.ts b/packages/eslint-plugin/tests/rules/await-thenable.test.ts
@@ -1,4 +1,4 @@
-import { RuleTester } from '@typescript-eslint/rule-tester';
+import { noFormat, RuleTester } from '@typescript-eslint/rule-tester';
 
 import rule from '../../src/rules/await-thenable';
 import { getFixturesRootDir } from '../RuleTester';
@@ -202,33 +202,83 @@ const doSomething = async (
 
   invalid: [
     {
-      code: `
-async function test() {
-  await 0;
-  await 'value';
-
-  await (Math.random() > 0.5 ? '' : 0);
-
-  class NonPromise extends Array {}
-  await new NonPromise();
-}
-      `,
+      code: 'await 0;',
       errors: [
         {
-          line: 3,
+          line: 1,
+          messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: ' 0;',
+            },
+          ],
+        },
+      ],
+    },
+    {
+      code: "await 'value';",
+      errors: [
+        {
+          line: 1,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: " 'value';",
+            },
+          ],
         },
+      ],
+    },
+    {
+      code: "async () => await (Math.random() > 0.5 ? '' : 0);",
+      errors: [
         {
-          line: 4,
+          line: 1,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: "async () =>  (Math.random() > 0.5 ? '' : 0);",
+            },
+          ],
         },
+      ],
+    },
+    {
+      code: noFormat`async () => await(Math.random() > 0.5 ? '' : 0);`,
+      errors: [
         {
-          line: 6,
+          line: 1,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: "async () => (Math.random() > 0.5 ? '' : 0);",
+            },
+          ],
         },
+      ],
+    },
+    {
+      code: `
+class NonPromise extends Array {}
+await new NonPromise();
+      `,
+      errors: [
         {
-          line: 9,
+          line: 3,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: `
+class NonPromise extends Array {}
+ new NonPromise();
+      `,
+            },
+          ],
         },
       ],
     },
@@ -247,58 +297,84 @@ async function test() {
         {
           line: 8,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: `
+async function test() {
+  class IncorrectThenable {
+    then() {}
+  }
+  const thenable = new IncorrectThenable();
+
+   thenable;
+}
+      `,
+            },
+          ],
         },
       ],
     },
     {
       code: `
-const doSomething = async (
-  obj1: { a?: { b?: { c?: () => void } } },
-  obj2: { a?: { b?: { c: () => void } } },
-  obj3: { a?: { b: { c?: () => void } } },
-  obj4: { a: { b: { c?: () => void } } },
-  obj5: { a?: () => { b?: { c?: () => void } } },
-  obj6?: { a: { b: { c?: () => void } } },
-  callback?: () => void,
-): Promise<void> => {
-  await obj1.a?.b?.c?.();
-  await obj2.a?.b?.c();
-  await obj3.a?.b.c?.();
-  await obj4.a.b.c?.();
-  await obj5.a?.().b?.c?.();
-  await obj6?.a.b.c?.();
-
-  await callback?.();
-};
+declare const callback: (() => void) | undefined;
+await callback?.();
       `,
       errors: [
         {
-          line: 11,
-          messageId,
-        },
-        {
-          line: 12,
-          messageId,
-        },
-        {
-          line: 13,
-          messageId,
-        },
-        {
-          line: 14,
-          messageId,
-        },
-        {
-          line: 15,
+          line: 3,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: `
+declare const callback: (() => void) | undefined;
+ callback?.();
+      `,
+            },
+          ],
         },
+      ],
+    },
+    {
+      code: `
+declare const obj: { a?: { b?: () => void } };
+await obj.a?.b?.();
+      `,
+      errors: [
         {
-          line: 16,
+          line: 3,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: `
+declare const obj: { a?: { b?: () => void } };
+ obj.a?.b?.();
+      `,
+            },
+          ],
         },
+      ],
+    },
+    {
+      code: `
+declare const obj: { a: { b: { c?: () => void } } } | undefined;
+await obj?.a.b.c?.();
+      `,
+      errors: [
         {
-          line: 18,
+          line: 3,
           messageId,
+          suggestions: [
+            {
+              messageId: 'removeAwait',
+              output: `
+declare const obj: { a: { b: { c?: () => void } } } | undefined;
+ obj?.a.b.c?.();
+      `,
+            },
+          ],
         },
       ],
     },