fix(amazon-cognito-identity-js): Use JavaScript fallbacks when RNAWSCognito not available. (#14602)

Author: osama-rizk

.github/workflows/callable-unit-tests.yml

@@ -20,6 +20,12 @@ jobs:
           path: amplify-js
       - name: Setup node and build the repository
         uses: ./amplify-js/.github/actions/node-and-build
+      - name: Clear dependency cache and reinstall
+        working-directory: ./amplify-js
+        run: |
+          rm -rf node_modules
+          yarn install
+        shell: bash
       - name: Run tests
         working-directory: ./amplify-js
         env:

packages/amazon-cognito-identity-js/__tests__/enhance-rn.test.js

@@ -0,0 +1,47 @@
+import BigInteger from '../src/BigInteger';
+import AuthenticationHelper from '../src/AuthenticationHelper';
+
+// Mock React Native
+jest.mock('react-native', () => ({
+	NativeModules: {
+		RNAWSCognito: null
+	}
+}));
+
+describe('enhance-rn fallbacks', () => {
+	beforeAll(() => {
+		global.RNAWSCognito = null;
+		require('../enhance-rn');
+	});
+
+	it('should provide JavaScript fallback for modPow when native module is null', (done) => {
+		const base = new BigInteger();
+		base.fromInt(2);
+		const exp = new BigInteger();
+		exp.fromInt(3);
+		const mod = new BigInteger();
+		mod.fromInt(5);
+
+		base.modPow(exp, mod, (err, result) => {
+			expect(err).toBeNull();
+			expect(result.toString(16)).toBe('3');
+			done();
+		});
+	});
+
+	it('should provide JavaScript fallback for calculateS when native module is null', (done) => {
+		const instance = new AuthenticationHelper('TestPool');
+		const xValue = new BigInteger('deadbeef', 16);
+		const serverValue = new BigInteger('abcd1234', 16);
+
+		// Set up required instance variables
+		instance.k = new BigInteger('deadbeef', 16);
+		instance.UValue = new BigInteger('abc', 16);
+
+		instance.calculateS(xValue, serverValue, (err, result) => {
+			expect(err).toBeNull();
+			expect(result).toBeInstanceOf(BigInteger);
+			done();
+		});
+	});
+});

packages/amazon-cognito-identity-js/enhance-rn.js

@@ -7,44 +7,60 @@ export * from './src';
 
 const { RNAWSCognito } = NativeModules;
 
+// Store the original functions before overriding
+const originalModPow = BigInteger.prototype.modPow;
+const originalCalculateS = src.AuthenticationHelper.prototype.calculateS;
+
 BigInteger.prototype.modPow = function nativeModPow(e, m, callback) {
-	RNAWSCognito.computeModPow(
-		{
-			target: this.toString(16),
-			value: e.toString(16),
-			modifier: m.toString(16),
-		},
-		(err, result) => {
-			if (err) {
-				return callback(new Error(err), null);
+	// Check if native module is available
+	if (RNAWSCognito && RNAWSCognito.computeModPow) {
+		RNAWSCognito.computeModPow(
+			{
+				target: this.toString(16),
+				value: e.toString(16),
+				modifier: m.toString(16),
+			},
+			(err, result) => {
+				if (err) {
+					return callback(new Error(err), null);
+				}
+				const bigIntResult = new BigInteger(result, 16);
+				return callback(null, bigIntResult);
 			}
-			const bigIntResult = new BigInteger(result, 16);
-			return callback(null, bigIntResult);
-		}
-	);
+		);
+	} else {
+		// Fall back to original JavaScript implementation
+		return originalModPow.call(this, e, m, callback);
+	}
 };
 
 src.AuthenticationHelper.prototype.calculateS = function nativeComputeS(
 	xValue,
 	serverBValue,
 	callback
 ) {
-	RNAWSCognito.computeS(
-		{
-			g: this.g.toString(16),
-			x: xValue.toString(16),
-			k: this.k.toString(16),
-			a: this.smallAValue.toString(16),
-			b: serverBValue.toString(16),
-			u: this.UValue.toString(16),
-		},
-		(err, result) => {
-			if (err) {
-				return callback(new Error(err), null);
+	// Check if native module is available
+	if (RNAWSCognito && RNAWSCognito.computeS) {
+		RNAWSCognito.computeS(
+			{
+				g: this.g.toString(16),
+				x: xValue.toString(16),
+				k: this.k.toString(16),
+				a: this.smallAValue.toString(16),
+				b: serverBValue.toString(16),
+				u: this.UValue.toString(16),
+			},
+			(err, result) => {
+				if (err) {
+					return callback(new Error(err), null);
+				}
+				const bigIntResult = new BigInteger(result, 16);
+				return callback(null, bigIntResult);
 			}
-			const bigIntResult = new BigInteger(result, 16);
-			return callback(null, bigIntResult);
-		}
-	);
+		);
+	} else {
+		// Fall back to original JavaScript implementation
+		return originalCalculateS.call(this, xValue, serverBValue, callback);
+	}
 	return undefined;
 };