Stricter parseValue coercion for built-in scalars

[dondonz]

This is an issue to track the progress of stricter parseValue coercion for built-in scalars.

Background

We initially made parseValue coercion stricter for built-in scalars to align with the JS reference implementation, and these changes were included in the v20.0 release. https://github.com/graphql-java/graphql-java/releases/tag/v20.0

Since then we've received reports that this breaking change is challenging. Although it's in line with the JS implementation, this change can potentially break clients. The plan is to provide a better migration pathway.

Progress log

• We reverted the stricter parseValue coercion in Revert stricter scalar parseValue coercion #3186. This so far is only on master and has not been released.
• PR to add an input interceptor to modify coercion in This introduces an input interceptor #3188. For example this interceptor can be used to add logging or customise coercion behaviour.
• @bbakerman added legacy coercing interceptor and hook for extra logging LegacyCoercing support #3218
• We released v20.3, which includes the revert https://github.com/graphql-java/graphql-java/releases/tag/v20.3
• We released v21.0, which includes a hook to monitor and/or intercept scalar values https://github.com/graphql-java/graphql-java/releases/tag/v21.0

[dondonz]

With today's release of v21.0, we're including an extra monitoring and interceptor callback for parseValue scalar coercion. See the release notes for more information: https://github.com/graphql-java/graphql-java/releases/tag/v21.0

We'll be adding the stricter scalar coercion at some point in the future, so please make use of these callbacks to learn which incoming values will be affected. I'll close the issue for now as we have reverted the stricter coercion in v20.3 and released the migration pathway in v21.0.