[screen-capture] Add is available async for availability check

docs/pages/versions/unversioned/sdk/screen-capture.md

@@ -96,6 +96,14 @@ import * as ScreenCapture from 'expo-screen-capture';
 
 ## Methods
 
+### `isAvailableAsync()`
+
+Returns whether the Screen Capture API is available on the current device.
+
+#### Returns
+
+Async `boolean`, indicating whether the Screen Capture API is available on the current device. Currently this resolves `true` on iOS and Android only.
+
 ### `usePreventScreenCapture(key)`
 
 A React hook to prevent screen capturing for as long as the owner component is mounted.

packages/expo-screen-capture/CHANGELOG.md

@@ -7,6 +7,7 @@
 ### 🎉 New features
 
 - Updated Android build configuration to target Android 11 (added support for Android SDK 30). ([#11647](https://github.com/expo/expo/pull/11647) by [@bbarthec](https://github.com/bbarthec))
+- Added `isAvailableAsync` method. ([#12121](https://github.com/expo/expo/pull/9675) by [@bycedric](https://github.com/bycedric))
 
 ### 🐛 Bug fixes
 

packages/expo-screen-capture/src/ExpoScreenCapture.web.ts

@@ -2,13 +2,4 @@ export default {
   get name(): string {
     return 'ExpoScreenCapture';
   },
-  async preventScreenCaptureAsync(tag = 'default'): Promise<null> {
-    return null;
-  },
-  async allowScreenCaptureAsync(tag = 'default'): Promise<null> {
-    return null;
-  },
-  async usePreventScreenCapture(tag = 'default'): Promise<null> {
-    return null;
-  },
 };

packages/expo-screen-capture/src/ScreenCapture.ts

@@ -1,4 +1,4 @@
-import { EventEmitter, Subscription } from '@unimodules/core';
+import { EventEmitter, Subscription, UnavailabilityError } from '@unimodules/core';
 import { useEffect } from 'react';
 
 import ExpoScreenCapture from './ExpoScreenCapture';
@@ -8,6 +8,15 @@ const emitter = new EventEmitter(ExpoScreenCapture);
 
 const onScreenshotEventName = 'onScreenshot';
 
+/**
+ * Returns whether the Screen Capture API is available on the current device.
+ *
+ * @returns Async `boolean`, indicating whether the Screen Capture API is available on the current device. Currently this resolves `true` on iOS and Android only.
+ */
+export async function isAvailableAsync(): Promise<boolean> {
+  return !!ExpoScreenCapture.preventScreenCapture && !!ExpoScreenCapture.allowScreenCapture;
+}
+
 /**
  * Prevents screenshots and screen recordings. If you are
  * already preventing screen capture, this method does nothing.
@@ -28,6 +37,10 @@ const onScreenshotEventName = 'onScreenshot';
  * ```
  */
 export async function preventScreenCaptureAsync(key: string = 'default'): Promise<void> {
+  if (!ExpoScreenCapture.preventScreenCapture) {
+    throw new UnavailabilityError('ScreenCapture', 'preventScreenCaptureAsync');
+  }
+
   if (!activeTags.has(key)) {
     activeTags.add(key);
     await ExpoScreenCapture.preventScreenCapture();
@@ -50,6 +63,10 @@ export async function preventScreenCaptureAsync(key: string = 'default'): Promis
  * ```
  */
 export async function allowScreenCaptureAsync(key: string = 'default'): Promise<void> {
+  if (!ExpoScreenCapture.preventScreenCapture) {
+    throw new UnavailabilityError('ScreenCapture', 'allowScreenCaptureAsync');
+  }
+
   activeTags.delete(key);
   if (activeTags.size === 0) {
     await ExpoScreenCapture.allowScreenCapture();

packages/expo-screen-capture/src/__tests__/ScreenCapture-test.native.js

@@ -2,6 +2,10 @@ import ExpoScreenCapture from '../ExpoScreenCapture';
 import * as ScreenCapture from '../ScreenCapture';
 
 describe('ScreenCapture methods are defined', () => {
+  it('isAvailableAsync is defined', async () => {
+    expect(ScreenCapture.isAvailableAsync).toBeDefined();
+  });
+
   it('preventScreenCapture is defined', async () => {
     expect(ScreenCapture.preventScreenCaptureAsync).toBeDefined();
   });
@@ -28,6 +32,10 @@ describe('Test key functionality', () => {
     await cleanUpTags();
   });
 
+  it('resolves true for isAvailableAsync on native platforms', async () => {
+    await expect(ScreenCapture.isAvailableAsync()).resolves.toBeTruthy();
+  });
+
   it('Will not call the native method if default key already active', async () => {
     await ScreenCapture.preventScreenCaptureAsync();
     await ScreenCapture.preventScreenCaptureAsync();

packages/expo-screen-capture/src/__tests__/ScreenCapture-test.web.js

@@ -0,0 +1,41 @@
+import * as ScreenCapture from '../ScreenCapture';
+
+describe('ScreenCapture methods are defined', () => {
+  it('isAvailableAsync is defined', async () => {
+    expect(ScreenCapture.isAvailableAsync).toBeDefined();
+  });
+
+  it('preventScreenCapture is defined', async () => {
+    expect(ScreenCapture.preventScreenCaptureAsync).toBeDefined();
+  });
+
+  it('allowScreenCapture is defined', async () => {
+    expect(ScreenCapture.allowScreenCaptureAsync).toBeDefined();
+  });
+
+  it('usePreventScreenCapture hook is defined', async () => {
+    expect(ScreenCapture.usePreventScreenCapture).toBeDefined();
+  });
+
+  it('addScreenshotListener is defined', async () => {
+    expect(ScreenCapture.addScreenshotListener).toBeDefined();
+  });
+
+  it('removeScreenshotListener is defined', async () => {
+    expect(ScreenCapture.removeScreenshotListener).toBeDefined();
+  });
+});
+
+describe('Test key functionality', () => {
+  it('resolves false for isAvailableAsync on web platform', async () => {
+    await expect(ScreenCapture.isAvailableAsync()).resolves.toBeFalsy();
+  });
+
+  it('throws for preventScreenCapture on web platform', async () => {
+    await expect(ScreenCapture.preventScreenCaptureAsync).rejects.toThrowError('not available');
+  });
+
+  it('throws for allowScreenCapture on web platform', async () => {
+    await expect(ScreenCapture.allowScreenCaptureAsync).rejects.toThrowError('not available');
+  });
+});