Cognito: support for partial UpdateUserPoolClient calls

Describe the feature

The UpdateUserPoolClient should support partial updates instead of having to provide every single parameter in the request.

Use Case

Currently, the process to update a user pool client through the SDK is very cumbersome. For example, if we only want to update the callbackURLs on an existing user pool client, we have to pass every single property with the existing value to the UpdateUserPoolClientRequest. This is because Cognito doesn't support partial updates:

If you don't provide a value for an attribute, Amazon Cognito sets it to its default value.

import software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient
import software.amazon.awssdk.services.cognitoidentityprovider.model.DescribeUserPoolClientRequest
import software.amazon.awssdk.services.cognitoidentityprovider.model.UpdateUserPoolClientRequest

class CognitoClient(
    private val cognitoConfig: CognitoConfig,
    private val cognitoClient: CognitoIdentityProviderClient,
) {
    // redacted other methods

    fun addCallbackUrlToAppClient(clientId: String, callbackUrl: String) {
        val describeUserPoolClientRequest = DescribeUserPoolClientRequest.builder()
            .clientId(clientId)
            .userPoolId(cognitoConfig.userPoolId)
            .build()

        val existingUserPoolClient = cognitoClient
            .describeUserPoolClient(describeUserPoolClientRequest)
            .userPoolClient()

        val existingCallbackUrls = existingUserPoolClient.callbackURLs()

        if (existingCallbackUrls.contains(callbackUrl)) {
            logger.info("Callback URL $callbackUrl already exists for client $clientId, skipping.")
            return
        }

        // We need to copy the list because it's immutable.
        val updatedCallbackUrls = existingCallbackUrls.toMutableList()
        updatedCallbackUrls.add(callbackUrl)

        /**
         * From the Cognito docs: "WARNING - If you don't provide a value for an attribute,
         * Amazon Cognito sets it to its default value."
         *
         * So here we are, setting all the attributes to their already existing values.
         */
        val updateRequest = UpdateUserPoolClientRequest.builder()
            .accessTokenValidity(existingUserPoolClient.accessTokenValidity())
            .allowedOAuthFlows(existingUserPoolClient.allowedOAuthFlows())
            .allowedOAuthFlowsUserPoolClient(existingUserPoolClient.allowedOAuthFlowsUserPoolClient())
            .allowedOAuthScopes(existingUserPoolClient.allowedOAuthScopes())
            .analyticsConfiguration(existingUserPoolClient.analyticsConfiguration())
            .authSessionValidity(existingUserPoolClient.authSessionValidity())
            // This is the only field we're _actually_ changing
            .callbackURLs(updatedCallbackUrls)
            .clientId(existingUserPoolClient.clientId())
            .clientName(existingUserPoolClient.clientName())
            .defaultRedirectURI(existingUserPoolClient.defaultRedirectURI())
            .enablePropagateAdditionalUserContextData(existingUserPoolClient.enablePropagateAdditionalUserContextData())
            .enableTokenRevocation(existingUserPoolClient.enableTokenRevocation())
            .explicitAuthFlows(existingUserPoolClient.explicitAuthFlows())
            .idTokenValidity(existingUserPoolClient.idTokenValidity())
            .logoutURLs(existingUserPoolClient.logoutURLs())
            .preventUserExistenceErrors(existingUserPoolClient.preventUserExistenceErrors())
            .readAttributes(existingUserPoolClient.readAttributes())
            .refreshTokenValidity(existingUserPoolClient.refreshTokenValidity())
            .supportedIdentityProviders(existingUserPoolClient.supportedIdentityProviders())
            .tokenValidityUnits(existingUserPoolClient.tokenValidityUnits())
            .userPoolId(existingUserPoolClient.userPoolId())
            .writeAttributes(existingUserPoolClient.writeAttributes())
            .build()

        cognitoClient.updateUserPoolClient(updateRequest)

        logger.info("Successfully added callback URL $callbackUrl to Cognito App Client $clientId")
    }
}

Proposed Solution

This probably will need updates on the Cognito service side. However, I do think it would be nice if the SDK could provide a convenience method in the meantime. I guess something like:

import software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient
import software.amazon.awssdk.services.cognitoidentityprovider.model.DescribeUserPoolClientRequest
import software.amazon.awssdk.services.cognitoidentityprovider.model.UpdateUserPoolClientRequest

class CognitoClient(
    private val cognitoConfig: CognitoConfig,
    private val cognitoClient: CognitoIdentityProviderClient,
) {
    // redacted other methods

    fun addCallbackUrlToAppClient(clientId: String, callbackUrl: String) {
        val describeUserPoolClientRequest = DescribeUserPoolClientRequest.builder()
            .clientId(clientId)
            .userPoolId(cognitoConfig.userPoolId)
            .build()

        val existingUserPoolClient = cognitoClient
            .describeUserPoolClient(describeUserPoolClientRequest)
            .userPoolClient()

        val existingCallbackUrls = existingUserPoolClient.callbackURLs()

        if (existingCallbackUrls.contains(callbackUrl)) {
            logger.info("Callback URL $callbackUrl already exists for client $clientId, skipping.")
            return
        }

        // We need to copy the list because it's immutable.
        val updatedCallbackUrls = existingCallbackUrls.toMutableList()
        updatedCallbackUrls.add(callbackUrl)

        val updateRequest = UpdateUserPoolClientRequest.builder()
            .callbackURLs(updatedCallbackUrls)
            .clientId(existingUserPoolClient.clientId())
            .build()

        cognitoClient.updateUserPoolClient(updateRequest, true)

        logger.info("Successfully added callback URL $callbackUrl to Cognito App Client $clientId")
    }
}

Note that updateUserPoolClient now takes a second parameter. This parameter could be named something like keepExistingParameters and default to false, so it's not a breaking change. If true, it could get the existing user pool (either by doing a describeUserPoolClient under the hood or require an existing UserPoolClientType to be passed).

Other Information

Acknowledgements

[ ] I may be able to implement this feature request
[ ] This feature might incur a breaking change

AWS Java SDK version used

2.25.50

JDK version used

17.0.10

Operating System and version

macOS 14.4.1

aws / aws-sdk-java-v2