chore: add unit tests for parsing claims (#1692)

Author: harsh62

AmplifyPlugins/Core/AWSPluginsCoreTests/Auth/AWSAuthServiceTests.swift

@@ -104,4 +104,53 @@ class AWSAuthServiceTests: XCTestCase {
         }
         XCTAssertEqual(jsonDecodeError.code, 3_840)
     }
+
+    func testClaimsWithSpecialCharacters() throws {
+        let tokenString = """
+                eyJraWQiOiJaS0s5ZUlZbmo4UEtGQzUrMHdMQUhJMjd0SWcxRkRRZU9ybW82SVwvdFkwbz0iLCJhbGciOiJSUzI1NiJ9\
+                .eyJmYy1pZCI6IjE2ZjFkOTM3LTY5YmQtNGI2OS1hMzJmLWYwNjkxNGY0YzIxOCIsInN1YiI6IjE2ZjFkOTM3LTY5YmQ\
+                tNGI2OS1hMzJmLWYwNjkxNGY0YzIxOCIsImlzcyI6Imh0dHBzOlwvXC9jb2duaXRvLWlkcC51cy1lYXN0LTEuYW1hem9\
+                uYXdzLmNvbVwvdXMtZWFzdC0xXzhqRVI4cHY0ViIsImNvZ25pdG86dXNlcm5hbWUiOiIxNmYxZDkzNy02OWJkLTRiNjk\
+                tYTMyZi1mMDY5MTRmNGMyMTgiLCJnaXZlbl9uYW1lIjoiQm_DsWEiLCJhdWQiOiI2bTZ1dWlocmhzM3BzbGI0amhhdHJ\
+                zYnBxYyIsImV2ZW50X2lkIjoiYjAzZjQ1YWMtM2FlMS0xMWU5LTlkZDItODcyODBlYTRiMGNhIiwidG9rZW5fdXNlIjo\
+                iaWQiLCJhdXRoX3RpbWUiOjE1NTEzMDc2NjEsImV4cCI6MTU1MTMxMTI2MSwiaWF0IjoxNTUxMzA3NjYxLCJmYW1pbHl\
+                fbmFtZSI6IkJhcsOnYSIsImVtYWlsIjoiaW5mb0Bkb25hYmFyY2EzLmRlIn0.OGT9siqf_tAYrhVA-EhYabz-L4ZNLe0\
+                w0N7fH4rASs0scRGm-34g96qmSZoD1j74bplIRcMqoFaDI0cLejyeeLN-z2ib1MDsuMnyq8cHfuu4x4qBGVcxWGkIOBj\
+                AEdsiU5U4xsEuaRpgC1rNiS7X6t0vQsDj3Jw3cV1XmJbeHaZB8D7EUMW6-zk4ZT2jKrpiaeaPTFoJJFOYiYdlJj4zkxX\
+                T2nzldS9K57Mwz91YgbjF_VCxPl84b-aiBoj7_ARdu8LDP2HHkpVoNslWYuusatBOOJvTT56Fa2kJzZqoUuAnGiC8AYU\
+                _YKpL_iu-wv5xnWHthuDCxhpl85cdROrAbA
+                """
+
+        let claimsResult = awsAuthService.getTokenClaims(tokenString: tokenString)
+        XCTAssertNotNil(claimsResult)
+        guard case .success(let claims) = claimsResult else {
+            XCTFail("Unable to parse claims")
+            return
+        }
+
+        guard let givenName = claims["given_name"] as? String else {
+            XCTFail("Claim should contain name")
+            return
+        }
+        XCTAssertEqual(givenName, "Boña")
+
+        guard let familyName = claims["family_name"] as? String else {
+            XCTFail("Claim should contain sub")
+            return
+        }
+        XCTAssertEqual(familyName, "Barça")
+
+        guard let iat = claims["iat"] as? Int else {
+            XCTFail("Claim should contain iat")
+            return
+        }
+
+        guard let sub = claims["sub"] as? String else {
+            XCTFail("Claim should contain sub")
+            return
+        }
+        XCTAssertEqual(sub, "16f1d937-69bd-4b69-a32f-f06914f4c218")
+
+        XCTAssertEqual(iat, 1_551_307_661)
+    }
 }