feat: UI testing API with queries and actions (#35)

Introduces UI testing capabilities with a new `@react-native-harness/ui` package that provides screen queries, user event simulation (press, type), and visual regression testing through `toMatchImageSnapshot`. This enables comprehensive component and integration testing with real device interactions, similar to React Testing Library but running on actual iOS and Android devices.

Author: V3RON

.nx/version-plans/version-plan-1768506559411.md

@@ -0,0 +1,5 @@
+---
+__default__: prerelease
+---
+
+Introduces UI testing capabilities with a new `@react-native-harness/ui` package that provides screen queries, user event simulation (press, type), and visual regression testing through `toMatchImageSnapshot`. This enables comprehensive component and integration testing with real device interactions, similar to React Testing Library but running on actual iOS and Android devices.

actions/android/action.yml

@@ -12,6 +12,11 @@ inputs:
     description: The project root directory
     required: false
     type: string
+  uploadVisualTestArtifacts:
+    description: Whether to upload visual test diff and actual images as artifacts
+    required: false
+    type: boolean
+    default: 'true'
 runs:
   using: 'composite'
   steps:
@@ -112,3 +117,12 @@ runs:
           echo $(pwd)
           adb install -r ${{ inputs.app }}
           pnpm react-native-harness --harnessRunner ${{ inputs.runner }}
+    - name: Upload visual test artifacts
+      if: always() && inputs.uploadVisualTestArtifacts == 'true'
+      uses: actions/upload-artifact@v4
+      with:
+        name: visual-test-diffs-android
+        path: |
+          ${{ inputs.projectRoot }}/**/__image_snapshots__/**/*-diff.png
+          ${{ inputs.projectRoot }}/**/__image_snapshots__/**/*-actual.png
+        if-no-files-found: ignore

actions/ios/action.yml

@@ -12,6 +12,11 @@ inputs:
     description: The project root directory
     required: false
     type: string
+  uploadVisualTestArtifacts:
+    description: Whether to upload visual test diff and actual images as artifacts
+    required: false
+    type: boolean
+    default: 'true'
 runs:
   using: 'composite'
   steps:
@@ -40,3 +45,12 @@ runs:
       working-directory: ${{ inputs.projectRoot }}
       run: |
         pnpm react-native-harness --harnessRunner ${{ inputs.runner }}
+    - name: Upload visual test artifacts
+      if: always() && inputs.uploadVisualTestArtifacts == 'true'
+      uses: actions/upload-artifact@v4
+      with:
+        name: visual-test-diffs-ios
+        path: |
+          ${{ inputs.projectRoot }}/**/__image_snapshots__/**/*-diff.png
+          ${{ inputs.projectRoot }}/**/__image_snapshots__/**/*-actual.png
+        if-no-files-found: ignore

actions/shared/index.cjs

@@ -29,9 +29,9 @@ var __toESM = (mod, isNodeMode, target) => (target = mod != null ? __create(__ge
   mod
 ));
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/picocolors/picocolors.js
+// ../../node_modules/picocolors/picocolors.js
 var require_picocolors = __commonJS({
-  "../../node_modules/.pnpm/[email protected]/node_modules/picocolors/picocolors.js"(exports2, module2) {
+  "../../node_modules/picocolors/picocolors.js"(exports2, module2) {
     "use strict";
     var p = process || {};
     var argv = p.argv || [];
@@ -102,9 +102,9 @@ var require_picocolors = __commonJS({
   }
 });
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/sisteransi/src/index.js
+// ../../node_modules/sisteransi/src/index.js
 var require_src = __commonJS({
-  "../../node_modules/.pnpm/[email protected]/node_modules/sisteransi/src/index.js"(exports2, module2) {
+  "../../node_modules/sisteransi/src/index.js"(exports2, module2) {
     "use strict";
     var ESC = "\x1B";
     var CSI = `${ESC}[`;
@@ -158,9 +158,9 @@ var require_src = __commonJS({
   }
 });
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/is-unicode-supported/index.js
+// ../../node_modules/is-unicode-supported/index.js
 var require_is_unicode_supported = __commonJS({
-  "../../node_modules/.pnpm/[email protected]/node_modules/is-unicode-supported/index.js"(exports2, module2) {
+  "../../node_modules/is-unicode-supported/index.js"(exports2, module2) {
     "use strict";
     module2.exports = () => {
       if (process.platform !== "win32") {
@@ -172,7 +172,7 @@ var require_is_unicode_supported = __commonJS({
   }
 });
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/external.js
+// ../../node_modules/zod/dist/esm/v3/external.js
 var external_exports = {};
 __export(external_exports, {
   BRAND: () => BRAND,
@@ -284,7 +284,7 @@ __export(external_exports, {
   void: () => voidType
 });
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/helpers/util.js
+// ../../node_modules/zod/dist/esm/v3/helpers/util.js
 var util;
 (function(util3) {
   util3.assertEqual = (_) => {
@@ -418,7 +418,7 @@ var getParsedType = (data) => {
   }
 };
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/ZodError.js
+// ../../node_modules/zod/dist/esm/v3/ZodError.js
 var ZodIssueCode = util.arrayToEnum([
   "invalid_type",
   "invalid_literal",
@@ -535,7 +535,7 @@ ZodError.create = (issues) => {
   return error;
 };
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/locales/en.js
+// ../../node_modules/zod/dist/esm/v3/locales/en.js
 var errorMap = (issue, _ctx) => {
   let message;
   switch (issue.code) {
@@ -636,7 +636,7 @@ var errorMap = (issue, _ctx) => {
 };
 var en_default = errorMap;
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/errors.js
+// ../../node_modules/zod/dist/esm/v3/errors.js
 var overrideErrorMap = en_default;
 function setErrorMap(map) {
   overrideErrorMap = map;
@@ -645,7 +645,7 @@ function getErrorMap() {
   return overrideErrorMap;
 }
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/helpers/parseUtil.js
+// ../../node_modules/zod/dist/esm/v3/helpers/parseUtil.js
 var makeIssue = (params) => {
   const { data, path: path4, errorMaps, issueData } = params;
   const fullPath = [...path4, ...issueData.path || []];
@@ -755,14 +755,14 @@ var isDirty = (x) => x.status === "dirty";
 var isValid = (x) => x.status === "valid";
 var isAsync = (x) => typeof Promise !== "undefined" && x instanceof Promise;
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/helpers/errorUtil.js
+// ../../node_modules/zod/dist/esm/v3/helpers/errorUtil.js
 var errorUtil;
 (function(errorUtil2) {
   errorUtil2.errToObj = (message) => typeof message === "string" ? { message } : message || {};
   errorUtil2.toString = (message) => typeof message === "string" ? message : message?.message;
 })(errorUtil || (errorUtil = {}));
 
-// ../../node_modules/.pnpm/[email protected]/node_modules/zod/dist/esm/v3/types.js
+// ../../node_modules/zod/dist/esm/v3/types.js
 var ParseInputLazyPath = class {
   constructor(parent, value, path4, key) {
     this._cachedPath = [];
@@ -4214,6 +4214,7 @@ var ConfigSchema = external_exports.object({
   appRegistryComponentName: external_exports.string().min(1, "App registry component name is required"),
   runners: external_exports.array(external_exports.any()).min(1, "At least one runner is required"),
   defaultRunner: external_exports.string().optional(),
+  webSocketPort: external_exports.number().optional().default(3001),
   bridgeTimeout: external_exports.number().min(1e3, "Bridge timeout must be at least 1 second").default(6e4),
   resetEnvironmentBetweenTestFiles: external_exports.boolean().optional().default(true),
   unstable__skipAlreadyIncludedModules: external_exports.boolean().optional().default(false),
@@ -4233,7 +4234,7 @@ var ConfigSchema = external_exports.object({
 // ../tools/dist/logger.js
 var import_node_util2 = __toESM(require("util"), 1);
 
-// ../../node_modules/.pnpm/@clack[email protected]/node_modules/@clack/core/dist/index.mjs
+// ../../node_modules/@clack/core/dist/index.mjs
 var import_node_process = require("process");
 var V = __toESM(require("readline"), 1);
 var import_node_readline = __toESM(require("readline"), 1);
@@ -4251,7 +4252,7 @@ var C = { actions: new Set(gt), aliases: /* @__PURE__ */ new Map([["k", "up"], [
 var At = globalThis.process.platform.startsWith("win");
 var G = Symbol("clack:cancel");
 
-// ../../node_modules/.pnpm/@clack[email protected]/node_modules/@clack/prompts/dist/index.mjs
+// ../../node_modules/@clack/prompts/dist/index.mjs
 var import_picocolors = __toESM(require_picocolors(), 1);
 var import_node_process2 = __toESM(require("process"), 1);
 var import_node_fs = require("fs");

apps/playground/ios/Podfile.lock

@@ -5,6 +5,34 @@ PODS:
   - FBLazyVector (0.82.1)
   - fmt (11.0.2)
   - glog (0.3.5)
+  - HarnessUI (1.0.0-alpha.20):
+    - boost
+    - DoubleConversion
+    - fast_float
+    - fmt
+    - glog
+    - hermes-engine
+    - RCT-Folly
+    - RCT-Folly/Fabric
+    - RCTRequired
+    - RCTTypeSafety
+    - React-Core
+    - React-debug
+    - React-Fabric
+    - React-featureflags
+    - React-graphics
+    - React-ImageManager
+    - React-jsi
+    - React-NativeModulesApple
+    - React-RCTFabric
+    - React-renderercss
+    - React-rendererdebug
+    - React-utils
+    - ReactCodegen
+    - ReactCommon/turbomodule/bridging
+    - ReactCommon/turbomodule/core
+    - SocketRocket
+    - Yoga
   - hermes-engine (0.82.1):
     - hermes-engine/Pre-built (= 0.82.1)
   - hermes-engine/Pre-built (0.82.1)
@@ -2331,6 +2359,7 @@ DEPENDENCIES:
   - FBLazyVector (from `../../../node_modules/react-native/Libraries/FBLazyVector`)
   - fmt (from `../../../node_modules/react-native/third-party-podspecs/fmt.podspec`)
   - glog (from `../../../node_modules/react-native/third-party-podspecs/glog.podspec`)
+  - "HarnessUI (from `../node_modules/@react-native-harness/ui`)"
   - hermes-engine (from `../../../node_modules/react-native/sdks/hermes-engine/hermes-engine.podspec`)
   - RCT-Folly (from `../../../node_modules/react-native/third-party-podspecs/RCT-Folly.podspec`)
   - RCTDeprecation (from `../../../node_modules/react-native/ReactApple/Libraries/RCTFoundation/RCTDeprecation`)
@@ -2418,6 +2447,8 @@ EXTERNAL SOURCES:
     :podspec: "../../../node_modules/react-native/third-party-podspecs/fmt.podspec"
   glog:
     :podspec: "../../../node_modules/react-native/third-party-podspecs/glog.podspec"
+  HarnessUI:
+    :path: "../node_modules/@react-native-harness/ui"
   hermes-engine:
     :podspec: "../../../node_modules/react-native/sdks/hermes-engine/hermes-engine.podspec"
     :tag: hermes-2025-09-01-RNv0.82.0-265ef62ff3eb7289d17e366664ac0da82303e101
@@ -2561,6 +2592,7 @@ SPEC CHECKSUMS:
   FBLazyVector: 0aa6183b9afe3c31fc65b5d1eeef1f3c19b63bfa
   fmt: a40bb5bd0294ea969aaaba240a927bd33d878cdd
   glog: 5683914934d5b6e4240e497e0f4a3b42d1854183
+  HarnessUI: 2957b94c9c4a7e6e54b636229f4aa5e3809936bf
   hermes-engine: 273e30e7fb618279934b0b95ffab60ecedb7acf5
   RCT-Folly: 846fda9475e61ec7bcbf8a3fe81edfcaeb090669
   RCTDeprecation: f17e2ebc07876ca9ab8eb6e4b0a4e4647497ae3a

apps/playground/jest.config.js

@@ -10,7 +10,7 @@ module.exports = {
       setupFilesAfterEnv: ['./src/setupFileAfterEnv.ts'],
       // This is necessary to prevent Jest from transforming the workspace packages.
       // Not needed in users projects, as they will have the packages installed in their node_modules.
-      transformIgnorePatterns: ['/packages/'],
+      transformIgnorePatterns: ['/packages/', '/node_modules/'],
     },
   ],
   collectCoverageFrom: ['./src/**/*.(ts|tsx)'],

apps/playground/package.json

@@ -11,6 +11,8 @@
   },
   "devDependencies": {
     "react-native-harness": "workspace:*",
+    "@react-native-harness/runtime": "workspace:*",
+    "@react-native-harness/ui": "workspace:*",
     "@react-native-community/cli": "20.0.0",
     "@react-native-community/cli-platform-android": "20.0.0",
     "@react-native-community/cli-platform-ios": "20.0.0",

apps/playground/src/__tests__/ui/__image_snapshots__/android/orange-square-element-only.png

@@ -0,0 +1,33 @@
+import { describe, test, render, fn, expect } from 'react-native-harness';
+import { screen, userEvent } from '@react-native-harness/ui';
+import { View, Text, Pressable } from 'react-native';
+
+describe('Actions', () => {
+  test('should press element found by testID', async () => {
+    const onPress = fn();
+
+    await render(
+      <View
+        style={{
+          flex: 1,
+          justifyContent: 'center',
+          alignItems: 'center',
+          backgroundColor: 'white',
+        }}
+      >
+        <Pressable
+          testID="this-is-test-id"
+          onPress={onPress}
+          style={{ padding: 10, backgroundColor: 'red' }}
+        >
+          <Text style={{ color: 'black' }}>This is a view with a testID</Text>
+        </Pressable>
+      </View>
+    );
+
+    const element = await screen.findByTestId('this-is-test-id');
+    await userEvent.press(element);
+
+    expect(onPress).toHaveBeenCalled();
+  });
+});