From c5bb31c46ea992f451bac6c76bf902582b8b119d Mon Sep 17 00:00:00 2001
From: Ruslan Shestopalyuk <rshest@meta.com>
Date: Fri, 25 Jul 2025 08:53:45 -0700
Subject: [PATCH] Add 'testWithArg' to Fantom benchmarking API (#52831)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52831

# Changelog
[Internal] -

The corresponding `testWithArg` API is similar to the existing `test` one for the Fantom benchmarks, except it would allow to run the same test several times in a parametrized manner, with the set of parameters specified as an array (for now, of numbers).

This allows to easily implement testing patterns such as we have in a View benchmark test, whereas we have a mostly duplicated test body doing a similar thing with 100, 1000, 1500 view component instances etc.

Reviewed By: rubennorte

Differential Revision: D78970312

fbshipit-source-id: 504b7aada648c7213ce698f088ac71d9fde8884b
---
 private/react-native-fantom/src/Benchmark.js | 74 ++++++++++++++++++--
 1 file changed, 69 insertions(+), 5 deletions(-)

diff --git a/private/react-native-fantom/src/Benchmark.js b/private/react-native-fantom/src/Benchmark.js
index fe352f7fa65..ae7c5fb78e3 100644
--- a/private/react-native-fantom/src/Benchmark.js
+++ b/private/react-native-fantom/src/Benchmark.js
@@ -35,9 +35,32 @@ type TestOptions = $ReadOnly<{
 
 type SuiteResults = Array<$ReadOnly<TaskResult>>;
 
+type TestWithArgName<TestArgType> = string | ((testArg: TestArgType) => string);
+
+type TestWithArgOptions<TestArgType> =
+  | FnOptions
+  | ((testArg: TestArgType) => FnOptions);
+
+interface ParameterizedTestFunction {
+  <TestArgType>(
+    testArgs: $ReadOnlyArray<TestArgType>,
+    name: TestWithArgName<TestArgType>,
+    fn: (testArg: TestArgType) => void,
+    options?: TestWithArgOptions<TestArgType>,
+  ): SuiteAPI;
+  only: <TestArgType>(
+    testArgs: $ReadOnlyArray<TestArgType>,
+    name: TestWithArgName<TestArgType>,
+    fn: (testArg: TestArgType) => void,
+    options?: TestWithArgOptions<TestArgType>,
+  ) => SuiteAPI;
+}
+
 interface TestFunction {
   (name: string, fn: () => void, options?: FnOptions): SuiteAPI;
   only: (name: string, fn: () => void, options?: FnOptions) => SuiteAPI;
+  // `each` allows to run the same test multiple times with different arguments, provided as an array of values:
+  each: ParameterizedTestFunction;
 }
 
 interface SuiteAPI {
@@ -45,15 +68,17 @@ interface SuiteAPI {
   verify(fn: (results: SuiteResults) => void): SuiteAPI;
 }
 
+interface TestTask {
+  name: string;
+  fn: () => void;
+  options: TestOptions | void;
+}
+
 export function suite(
   suiteName: string,
   suiteOptions?: SuiteOptions = {},
 ): SuiteAPI {
-  const tasks: Array<{
-    name: string,
-    fn: () => void,
-    options: TestOptions | void,
-  }> = [];
+  const tasks: Array<TestTask> = [];
   const verifyFns = [];
 
   global.it(suiteName, () => {
@@ -165,6 +190,45 @@ export function suite(
     return suiteAPI;
   };
 
+  const testWithArg = <TestArgType>(
+    testArg: TestArgType,
+    name: TestWithArgName<TestArgType>,
+    fn: (testArg: TestArgType) => void,
+    options?: TestWithArgOptions<TestArgType>,
+    only?: boolean = false,
+  ): TestTask => {
+    const taskName =
+      typeof name === 'function'
+        ? name(testArg)
+        : `${name} [arg=${String(testArg)}]`;
+    const taskOptions =
+      typeof options === 'function' ? options(testArg) : options;
+    const taskFn = () => fn(testArg);
+    return {name: taskName, fn: taskFn, options: {...taskOptions, only}};
+  };
+
+  // $FlowIssue[incompatible-type]
+  const testEach: ParameterizedTestFunction = <TestArgType>(
+    testArgs: $ReadOnlyArray<TestArgType>,
+    name: TestWithArgName<TestArgType>,
+    fn: (testArg: TestArgType) => void,
+    options?: TestWithArgOptions<TestArgType>,
+  ): SuiteAPI => {
+    for (const testArg of testArgs) {
+      tasks.push(testWithArg(testArg, name, fn, options));
+    }
+    return suiteAPI;
+  };
+
+  testEach.only = (testArgs, name, fn, options) => {
+    for (const testArg of testArgs) {
+      tasks.push(testWithArg(testArg, name, fn, options, true));
+    }
+    return suiteAPI;
+  };
+
+  test.each = testEach;
+
   const suiteAPI = {
     test,
     verify(fn: (results: SuiteResults) => void): SuiteAPI {