1. Refactoring to create getRoleNameFromArn method in SigV4AuthProvider.java and unit test to validate.

2. Code formatting changes in SigV4AuthProvider.java

Author: akshayar

src/main/java/software/aws/mcs/auth/SigV4AuthProvider.java

@@ -133,7 +133,7 @@ public SigV4AuthProvider() {
      */
     public SigV4AuthProvider(DriverContext driverContext) {
         this(driverContext.getConfig().getDefaultProfile().getString(REGION_OPTION, getDefaultRegion()),
-                driverContext.getConfig().getDefaultProfile().getString(ROLE_OPTION, null));
+             driverContext.getConfig().getDefaultProfile().getString(ROLE_OPTION, null));
     }
 
     /**
@@ -393,14 +393,10 @@ static int indexOf(byte[] target, byte[] pattern) {
      * @param stsRegion The region of the STS endpoint
      * @return The STS role credential provider
      */
-    private static StsAssumeRoleCredentialsProvider createSTSRoleCredentialProvider(String roleArn,
-                                                                     String stsRegion) {
+    private static StsAssumeRoleCredentialsProvider createSTSRoleCredentialProvider(@NotNull String roleArn,
+                                                                            @NotNull String stsRegion) {
         //Get role name from ARN
-        String[] arnParts = roleArn.split("/");
-        if(arnParts.length < 2){
-            throw new IllegalArgumentException("Invalid role ARN");
-        }
-        String roleName = arnParts[arnParts.length - 1];
+        String roleName = getRoleNameFromArn(roleArn);
         final String sessionName="keyspaces-session-"+roleName+System.currentTimeMillis();
         StsClient stsClient = StsClient.builder()
                 .region(Region.of(stsRegion))
@@ -415,6 +411,20 @@ private static StsAssumeRoleCredentialsProvider createSTSRoleCredentialProvider(
                 .build();
     }
 
+    /**
+     * Extracts the role name from the ARN.
+     * @param roleArn The ARN of the role to assume
+     * @return
+     */
+    static String getRoleNameFromArn(@NotNull String roleArn) {
+        String[] arnParts = roleArn.split("/");
+        if(arnParts.length < 2){
+            throw new IllegalArgumentException("Invalid role ARN");
+        }
+        String roleName = arnParts[arnParts.length - 1];
+        return roleName;
+    }
+
     /**
      * Gets the default region for SigV4 if region is not provided.
      * @return Default region

src/test/java/software/aws/mcs/auth/SigV4AuthProviderTest.java

@@ -87,4 +87,21 @@ public void testPartialTrailingIndexOf() {
         assertEquals(-1, SigV4AuthProvider.indexOf(target, pattern));
     }
 
+
+    @Test
+    public void testGetRoleNameFromArn() {
+        String arn = "arn:aws:iam::ACCOUNT_ID:role/keyspaces-act2-role";
+        assertEquals("keyspaces-act2-role", SigV4AuthProvider.getRoleNameFromArn(arn));
+    }
+
+    @Test
+    public void testGetRoleNameFromArnFailure() {
+        assertThrows(IllegalArgumentException.class, () -> SigV4AuthProvider.getRoleNameFromArn(""));
+        assertThrows(IllegalArgumentException.class, () -> SigV4AuthProvider.getRoleNameFromArn("roleName"));
+        assertThrows(IllegalArgumentException.class, () -> SigV4AuthProvider.getRoleNameFromArn("illegalerolearn:rolename"));
+    }
+
+
+
+
 }