chore: reseting account during oauth init

src/main/java/com/twilio/Twilio.java

@@ -2,8 +2,6 @@
 
 import com.twilio.annotations.Beta;
 import com.twilio.auth_strategy.AuthStrategy;
-import com.twilio.constant.EnumConstants;
-import com.twilio.credential.ClientCredentialProvider;
 import com.twilio.exception.ApiException;
 import com.twilio.exception.AuthenticationException;
 import com.twilio.exception.CertificateValidationException;
@@ -13,8 +11,6 @@
 import com.twilio.http.Request;
 import com.twilio.http.Response;
 import com.twilio.http.TwilioRestClient;
-import com.twilio.http.bearertoken.ApiTokenManager;
-import com.twilio.http.bearertoken.TokenManager;
 import lombok.Getter;
 
 import java.util.ArrayList;
@@ -76,6 +72,7 @@ public static synchronized void init(final String username, final String passwor
     @Beta
     public static synchronized void init(final CredentialProvider credentialProvider) {
         Twilio.setCredentialProvider(credentialProvider);
+        Twilio.setAccountSid(null);
     }
 
     @Beta
@@ -88,11 +85,12 @@ private static void setCredentialProvider(final CredentialProvider credentialPro
         if (credentialProvider == null) {
             throw new AuthenticationException("Credential Provider can not be null");
         }
-
-        if (!credentialProvider.equals(Twilio.credentialProvider)) { // TODO: Write equals method in credential provider implementation class.
+        
+        if (!credentialProvider.equals(Twilio.credentialProvider)) {
             Twilio.invalidate();
         }
-        // TODO: In case of Basic Auth, How to set account_sid ?
+        // Invalidate Basic Creds as they might be initialized via environment variables.
+        invalidateBasicCreds();
         Twilio.credentialProvider = credentialProvider;
     }
 
@@ -123,6 +121,7 @@ public static synchronized void setUsername(final String username) {
         if (!username.equals(Twilio.username)) {
             Twilio.invalidate();
         }
+        Twilio.invalidateOAuthCreds();
 
         Twilio.username = username;
     }
@@ -141,6 +140,7 @@ public static synchronized void setPassword(final String password) {
         if (!password.equals(Twilio.password)) {
             Twilio.invalidate();
         }
+        Twilio.invalidateOAuthCreds();
 
         Twilio.password = password;
     }
@@ -215,13 +215,13 @@ private static TwilioRestClient buildRestClient() {
         if (Twilio.username == null || Twilio.password == null) {
             if (credentialProvider == null) {
                 throw new AuthenticationException(
-                        "TwilioRestClient was used before AccountSid and AuthToken were set, please call Twilio.init()"
+                        "Credentials have not been initialized or changed, please call Twilio.init()"
                 );
             }
         }
         TwilioRestClient.Builder builder;
         if (credentialProvider != null) {
-            AuthStrategy authStrategy = credentialProvider.toAuthStrategy(); // Does Code need to be thread safe ?
+            AuthStrategy authStrategy = credentialProvider.toAuthStrategy();
             builder = new TwilioRestClient.Builder(authStrategy);
         } else {
             builder = new TwilioRestClient.Builder(Twilio.username, Twilio.password);
@@ -312,6 +312,15 @@ private static void invalidate() {
         Twilio.restClient = null;
     }
 
+    private static void invalidateOAuthCreds() {
+        Twilio.credentialProvider = null;
+    }
+
+    private static void invalidateBasicCreds() {
+        Twilio.username = null;
+        Twilio.password = null;
+    }
+
     /**
      * Attempts to gracefully shutdown the ExecutorService if it is present.
      */

src/main/java/com/twilio/auth_strategy/TokenAuthStrategy.java

@@ -32,7 +32,8 @@ public void fetchToken() {
         if (this.token == null || this.token.isEmpty() || isTokenExpired(this.token)) {
             synchronized (TokenAuthStrategy.class){
                 if (this.token == null || this.token.isEmpty() || isTokenExpired(this.token)) {
-                    this.token = tokenManager.fetchAccessToken(); // TODO: Exceptional handling
+
+                    this.token = tokenManager.fetchAccessToken();
                 }
             }
         }

src/main/java/com/twilio/credential/ClientCredentialProvider.java

@@ -6,20 +6,17 @@
 import com.twilio.auth_strategy.TokenAuthStrategy;
 import com.twilio.constant.EnumConstants;
 import com.twilio.exception.AuthenticationException;
-import com.twilio.http.Request;
+
 import com.twilio.http.bearertoken.ApiTokenManager;
 import com.twilio.http.bearertoken.TokenManager;
-import com.twilio.rest.oauth.v1.Token;
-import lombok.Getter;
-import lombok.Setter;
+
+import java.util.Objects;
 
 @Beta
 public class ClientCredentialProvider extends CredentialProvider {
     private String grantType;
     private String clientId;
     private String clientSecret;
-    @Setter
-    @Getter
     private TokenManager tokenManager;
 
     public ClientCredentialProvider(String clientId, String clientSecret) {
@@ -54,4 +51,20 @@ public AuthStrategy toAuthStrategy() {
         }
         return new TokenAuthStrategy(tokenManager);
     }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        ClientCredentialProvider other = (ClientCredentialProvider) o;
+        return Objects.equals(clientId, other.clientId) &&
+                Objects.equals(clientSecret, other.clientSecret) &&
+                Objects.equals(tokenManager, other.tokenManager);
+    }
 }

src/main/java/com/twilio/http/bearertoken/ApiTokenManager.java

@@ -1,10 +1,11 @@
 package com.twilio.http.bearertoken;
 
 import com.twilio.annotations.Beta;
-import com.twilio.exception.ApiException;
 import com.twilio.rest.previewiam.v1.Token;
 import com.twilio.rest.previewiam.v1.TokenCreator;
 
+import java.util.Objects;
+
 @Beta
 public class ApiTokenManager implements TokenManager {
 
@@ -19,21 +20,13 @@ public class ApiTokenManager implements TokenManager {
 
     @Override
     public String fetchAccessToken() {
-        TokenCreator tokenCreator = Token.creator(grantType, clientId).setClientSecret(clientSecret); // TODO: Change this
+        TokenCreator tokenCreator = Token.creator(grantType, clientId).setClientSecret(clientSecret);
         if (this.code != null) tokenCreator.setCode(code);
         if (this.redirectUri != null) tokenCreator.setRedirectUri(redirectUri);
         if (this.audience != null) tokenCreator.setAudience(audience);
         if (this.refreshToken != null) tokenCreator.setRefreshToken(refreshToken);
         if (this.scope != null) tokenCreator.setScope(scope);
-        Token token;
-        try {
-            token = tokenCreator.create();
-            if(token == null || token.getAccessToken() == null){
-                throw new ApiException("Token creation failed");
-            }
-        } catch(Exception e){
-            throw new ApiException("Token creation failed");
-        }
+        Token token = tokenCreator.create();
         return token.getAccessToken();
     }
 
@@ -53,4 +46,25 @@ public ApiTokenManager(String grantType, String clientId, String clientSecret, S
         this.refreshToken = refreshToken;
         this.scope = scope;
     }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        ApiTokenManager other = (ApiTokenManager) o;
+        return Objects.equals(grantType, other.grantType) &&
+                Objects.equals(clientId, other.clientId) &&
+                Objects.equals(clientSecret, other.clientSecret) &&
+                Objects.equals(code, other.code) &&
+                Objects.equals(redirectUri, other.redirectUri) &&
+                Objects.equals(audience, other.audience) &&
+                Objects.equals(refreshToken, other.refreshToken) &&
+                Objects.equals(scope, other.scope);
+    }
 }