feat: enhance prompt handling in GetAuthURLWithInvitation

- Updated GetAuthURLWithInvitation to set the prompt parameter to "create" only if no custom prompt is provided.
- Added tests to verify that the prompt parameter behaves correctly with and without invitation codes, ensuring custom prompts are preserved.
- Improved test coverage for scenarios involving invitation codes and prompt handling.

Author: BrandtKruger

oauth2/authorization_code/authorization_code.go

@@ -157,6 +157,9 @@ func (flow *AuthorizationCodeFlow) GetAuthURLWithInvitation(invitationCode strin
 	if invitationCode != "" {
 		query.Set("invitation_code", invitationCode)
 		query.Set("is_invitation", "true")
+		if query.Get("prompt") == "" {
+			query.Set("prompt", "create")
+		}
 	}
 
 	// Add PKCE parameters if enabled

oauth2/authorization_code/authorization_code_test.go

@@ -107,12 +107,25 @@ func TestGetAuthURLWithInvitation(t *testing.T) {
 	assert.NotEmpty(authURL, "AuthURL cannot be empty")
 	assert.Contains(authURL, "invitation_code=inv_123456789", "AuthURL should contain invitation_code parameter")
 	assert.Contains(authURL, "is_invitation=true", "AuthURL should contain is_invitation parameter")
+	assert.Contains(authURL, "prompt=create", "AuthURL should contain prompt=create parameter when invitation code is provided")
 
 	// Test without invitation code (empty string)
 	authURLNoInvitation := kindeAuthFlow.GetAuthURLWithInvitation("")
 	assert.NotEmpty(authURLNoInvitation, "AuthURL cannot be empty")
 	assert.NotContains(authURLNoInvitation, "invitation_code", "AuthURL should not contain invitation_code when empty")
 	assert.NotContains(authURLNoInvitation, "is_invitation", "AuthURL should not contain is_invitation when empty")
+	assert.NotContains(authURLNoInvitation, "prompt=create", "AuthURL should not contain prompt=create when invitation code is empty")
+
+	// Test that existing prompt value is not overwritten
+	kindeAuthFlowWithPrompt, _ := NewAuthorizationCodeFlow(
+		testKindeServerURL, "b9da18c441b44d81bab3e8232de2e18d", "client_secret", callbackURL,
+		WithSessionHooks(newTestSessionHooks()),
+		WithCustomStateGenerator(func(*AuthorizationCodeFlow) string { return "test_state" }),
+		WithPrompt("login"), // Set a custom prompt
+	)
+	authURLWithCustomPrompt := kindeAuthFlowWithPrompt.GetAuthURLWithInvitation(invitationCode)
+	assert.Contains(authURLWithCustomPrompt, "prompt=login", "AuthURL should preserve custom prompt value")
+	assert.NotContains(authURLWithCustomPrompt, "prompt=create", "AuthURL should not overwrite custom prompt with create")
 }
 
 func TestWithInvitationCodeOption(t *testing.T) {