fix(prefer-mock-return-shorthand): ignore use of update expressions (#858)

Author: G-Rath

src/rules/prefer-mock-return-shorthand.ts

@@ -71,7 +71,10 @@ export default createEslintRule<Options, MESSAGE_IDS>({
 
         const returnNode = findSingleReturnArgumentNode(arg)
 
-        if (!returnNode) {
+        if (
+          !returnNode ||
+          returnNode.type === AST_NODE_TYPES.UpdateExpression
+        ) {
           return
         }
 

tests/prefer-mock-return-shorthand.test.ts

@@ -31,6 +31,28 @@ ruleTester.run(RULE_NAME, rule, {
         return 2;
       });
     `,
+    'aVariable.mockImplementation(() => value++)',
+    'aVariable.mockImplementationOnce(() => --value)',
+    `
+      const aValue = 0;
+      aVariable.mockImplementation(() => {
+        return aValue++;
+      });
+    `,
+    `
+      aVariable.mockImplementation(() => {
+        aValue += 1;
+
+        return aValue;
+      });
+    `,
+    `
+      aVariable.mockImplementation(() => {
+        aValue++;
+
+        return aValue;
+      });
+    `,
     'aVariable.mockReturnValue()',
     'aVariable.mockReturnValue(1)',
     'aVariable.mockReturnValue("hello world")',