fix(no-wait-for-side-effects): false negatives in variables declarations (#677)

fix: false negatives in variables declarations

Closes #368

Author: sjarva

lib/rules/no-wait-for-side-effects.ts

@@ -120,6 +120,40 @@ export default createTestingLibraryRule<Options, MessageIds>({
 			return node.expressions.some(isRenderInAssignmentExpression);
 		}
 
+		/**
+		 * Checks if there are side effects in variable declarations.
+		 *
+		 * For example, these variable declarations have side effects:
+		 * const a = userEvent.doubleClick(button);
+		 * const b = fireEvent.click(button);
+		 * const wrapper = render(<Component />);
+		 *
+		 * @param node
+		 * @returns {Boolean} Boolean indicating if variable declarataion has side effects
+		 */
+		function isSideEffectInVariableDeclaration(
+			node: TSESTree.VariableDeclaration
+		): boolean {
+			return node.declarations.some((declaration) => {
+				if (isCallExpression(declaration.init)) {
+					const test = getPropertyIdentifierNode(declaration.init);
+
+					if (!test) {
+						return false;
+					}
+
+					return (
+						helpers.isFireEventUtil(test) ||
+						helpers.isUserEventUtil(test) ||
+						helpers.isRenderUtil(test)
+					);
+				}
+				return false;
+			});
+
+			return false;
+		}
+
 		function getSideEffectNodes(
 			body: TSESTree.Node[]
 		): TSESTree.ExpressionStatement[] {
@@ -135,6 +169,13 @@ export default createTestingLibraryRule<Options, MessageIds>({
 					return true;
 				}
 
+				if (
+					isVariableDeclaration(node) &&
+					isSideEffectInVariableDeclaration(node)
+				) {
+					return true;
+				}
+
 				const expressionIdentifier = getPropertyIdentifierNode(node);
 
 				if (!expressionIdentifier) {

tests/lib/rules/no-wait-for-side-effects.test.ts

@@ -795,5 +795,25 @@ ruleTester.run(RULE_NAME, rule, {
 				{ line: 12, column: 13, messageId: 'noSideEffectsWaitFor' },
 			],
 		},
+		// side effects (userEvent, fireEvent or render) in variable declarations
+		...SUPPORTED_TESTING_FRAMEWORKS.flatMap((testingFramework) => [
+			{
+				// Issue #368, https://github.com/testing-library/eslint-plugin-testing-library/issues/368
+				code: `
+        import { waitFor } from '${testingFramework}';
+        import userEvent from '@testing-library/user-event'
+        await waitFor(() => {
+          const a = userEvent.click(button);
+          const b = fireEvent.click(button);
+          const wrapper = render(<App />);
+        })
+        `,
+				errors: [
+					{ line: 5, column: 11, messageId: 'noSideEffectsWaitFor' },
+					{ line: 6, column: 11, messageId: 'noSideEffectsWaitFor' },
+					{ line: 7, column: 11, messageId: 'noSideEffectsWaitFor' },
+				],
+			} as const,
+		]),
 	],
 });