feat: create a fixer

Author: y-hsgw

lib/rules/await-async-utils.ts

@@ -3,17 +3,19 @@ import { ASTUtils } from '@typescript-eslint/utils';
 import { createTestingLibraryRule } from '../create-testing-library-rule';
 import {
 	findClosestCallExpressionNode,
+	findClosestFunctionExpressionNode,
 	getDeepestIdentifierNode,
 	getFunctionName,
 	getInnermostReturningFunction,
+	getReferenceNode,
 	getVariableReferences,
 	isCallExpression,
 	isObjectPattern,
 	isPromiseHandled,
 	isProperty,
 } from '../node-utils';
 
-import type { TSESTree } from '@typescript-eslint/utils';
+import type { TSESLint, TSESTree } from '@typescript-eslint/utils';
 
 export const RULE_NAME = 'await-async-utils';
 export type MessageIds = 'asyncUtilWrapper' | 'awaitAsyncUtil';
@@ -40,6 +42,7 @@ export default createTestingLibraryRule<Options, MessageIds>({
 				'Promise returned from {{ name }} wrapper over async util must be handled',
 		},
 		schema: [],
+		fixable: 'code',
 	},
 	defaultOptions: [],
 
@@ -90,6 +93,33 @@ export default createTestingLibraryRule<Options, MessageIds>({
 				}
 			}
 		}
+		function wrapWithFunctionExpressionFix(
+			fixer: TSESLint.RuleFixer,
+			ruleFix: TSESLint.RuleFix,
+			functionExpression:
+				| TSESTree.ArrowFunctionExpression
+				| TSESTree.FunctionDeclaration
+				| TSESTree.FunctionExpression
+				| null
+		) {
+			if (functionExpression && !functionExpression.async) {
+				/**
+				 * Mutate the actual node so if other nodes exist in this
+				 * function expression body they don't also try to fix it.
+				 */
+				functionExpression.async = true;
+
+				return [ruleFix, fixer.insertTextBefore(functionExpression, 'async ')];
+			}
+			return ruleFix;
+		}
+
+		function insertAwaitBeforeNode(
+			fixer: TSESLint.RuleFixer,
+			node: TSESTree.Node
+		) {
+			return fixer.insertTextBefore(node, 'await ');
+		}
 
 		/*
 			Either we report a direct usage of an async util or a usage of a wrapper
@@ -155,6 +185,7 @@ export default createTestingLibraryRule<Options, MessageIds>({
 					context,
 					closestCallExpression.parent
 				);
+				const functionExpression = findClosestFunctionExpressionNode(node);
 
 				if (references.length === 0) {
 					if (!isPromiseHandled(callExpressionIdentifier)) {
@@ -164,6 +195,17 @@ export default createTestingLibraryRule<Options, MessageIds>({
 							data: {
 								name: callExpressionIdentifier.name,
 							},
+							fix: (fixer) => {
+								const referenceNode = getReferenceNode(
+									callExpressionIdentifier
+								);
+								const awaitFix = insertAwaitBeforeNode(fixer, referenceNode);
+								return wrapWithFunctionExpressionFix(
+									fixer,
+									awaitFix,
+									functionExpression
+								);
+							},
 						});
 					}
 				} else {
@@ -176,6 +218,14 @@ export default createTestingLibraryRule<Options, MessageIds>({
 								data: {
 									name: callExpressionIdentifier.name,
 								},
+								fix: (fixer) => {
+									const awaitFix = insertAwaitBeforeNode(fixer, referenceNode);
+									return wrapWithFunctionExpressionFix(
+										fixer,
+										awaitFix,
+										functionExpression
+									);
+								},
 							});
 							return;
 						}