bug(r2dbc): enable_iam_auth throws java.lang.ClassCastException

[mpeddada1]

Due to a limitation in R2DBC, extra options specified through the r2dbc url are automatically typed as String. Therefore, setting the enable_iam_auth option in the r2dbc connection url (r2dbc:gcp:postgres://{INSTANCE_CONNECTION_NAME}/{DATABASE_NAME}?ENABLE_IAM_AUTH=true) results in the following error :

Caused by: java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Boolean (java.lang.String and java.lang.Boolean are in module java.base of loader 'bootstrap')
	at com.google.cloud.sql.core.GcpConnectionFactoryProvider.createFactory(GcpConnectionFactoryProvider.java:103)
	at com.google.cloud.sql.core.GcpConnectionFactoryProvider.create(GcpConnectionFactoryProvider.java:96)
	at io.r2dbc.spi.ConnectionFactories.find(ConnectionFactories.java:112)
	at io.r2dbc.spi.ConnectionFactories.get(ConnectionFactories.java:142)
	at org.springframework.boot.r2dbc.ConnectionFactoryBuilder$OptionsCapableWrapper.buildAndWrap(ConnectionFactoryBuilder.java:203)
	at org.springframework.boot.r2dbc.ConnectionFactoryBuilder$PoolingAwareOptionsCapableWrapper.buildAndWrap(ConnectionFactoryBuilder.java:216)
	at org.springframework.boot.r2dbc.ConnectionFactoryBuilder.build(ConnectionFactoryBuilder.java:189)
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations.createConnectionFactory(ConnectionFactoryConfigurations.java:61)
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$Pool.connectionFactory(ConnectionFactoryConfigurations.java:73)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
	... 102 more

Perhaps doing something similar to CoreSocketFactory#create where we call Boolean.parseBoolean() could help address this. Enabling IAM auth through the JDBC connection url (jdbc:postgresql://google/{DATABASE_NAME}?socketFactory=com.google.cloud.sql.postgres.SocketFactory&cloudSqlInstance={INSTANCE_CONNECTION_NAME}?enableIamAuth=true&sslmode=disable works as expected.

[kurtisvg]

Thanks for taking the time to file a bug. I added a regression test and fix in #688.

[mpeddada1]

Thank you for the fix!