Split validation via dry-rb into seperate gem

[pfeiffer]

Hi!

Since version 2.1 config supports validation via dry-rb. Unfortunately this dependency results in a quite high memory usage.

Output using derailed bundle:mem:

 rails/all: 25.1523 MiB
    rails: 9.4883 MiB
       ...
 config: 7.1172 MiB
    config/validation/schema: 6.6563 MiB (Also required by: config/validation/schema)
      dry-schema: 6.6367 MiB
        dry/schema: 6.6211 MiB
          dry/schema/dsl: 6.5039 MiB
            dry/schema/config: 4.3203 MiB (Also required by: dry/schema/rule_applier)
              dry/schema/type_container: 3.8398 MiB (Also required by: dry/schema/processor)
                dry/types: 3.4727 MiB (Also required by: dry/schema/types)
                  dry/types/nominal: 1.8398 MiB
                    dry/types/builder: 1.0703 MiB
                      dry/types/constrained: 0.707 MiB
                        dry/types/constraints: 0.6523 MiB
                          dry/logic/rule_compiler: 0.5977 MiB (Also required by: dry/schema/compiler)
                            dry/logic/rule: 0.5234 MiB (Also required by: dry/logic/rule/predicate)
                              dry/logic/operations: 0.4023 MiB
                    dry/types/array: 0.3008 MiB
                  dry/types/core: 0.6758 MiB
                  dry/types/inflector: 0.3984 MiB
                    dry/inflector: 0.3242 MiB
                dry/container: 0.3555 MiB (Also required by: dry-container, dry/types/container)
            dry/schema/macros: 1.0977 MiB
              dry/schema/macros/optional: 0.6094 MiB
                dry/schema/macros/key: 0.582 MiB (Also required by: dry/schema/macros/required)
                  dry/schema/processor: 0.4922 MiB (Also required by: dry/schema/dsl, dry/schema/params)
                    dry/schema/rule_applier: 0.4531 MiB (Also required by: dry/schema/dsl)
                      dry/schema/message_compiler: 0.3125 MiB

In our app with quite a lot of dependencies, this makes config the second most memory hungry gem after rails.

Would it be an idea to split the validation feature into a separate optional gem, that could be included if this functionality is wanted? This would cut down significantly on the memory impact of including the core config gem making inclusion of dry-rb optional for the developer.

[pfeiffer]

I digged a little in the code and found #253 that defers requiring dry-validation until a schema is defined. After upgrading the gem to latest version, I no longer see config using as much memory as mentioned above.

Closing this issue for now :-)

[pkuczynski]

I am glad we had you covered ;)

[BuonOmo]

@pkuczynski actually...

I'll maybe open a PR here with more information, but if you could tell me your interest in my next proposition I'd be glad.

Depending on dry-validation doesn't just bring runtime issues (which are covered, as discussed in this conversation). It also bring:

• a larger stack, hence longer bundle install and necessity for more ROM in production (which can matter, for instance Heroku instances ask for a quite small app size )
• a gemfile lock dependency, forcing version of dry-* gems. Some may want to still be in 0.X, or when dry 2.X goes out, some may want to jump into that, and if they are not using the schema feature for config, it is sad to block those people.

Hence my design intention is:

1. replace the dependency with a dev-dependency,
2. check at runtime if the dependency is met, and if is matches dev-dependency expected version,
3. add related tests :)

Here's a fork we're using at Stuart in the meantime: https://github.com/StuartApp/config

Would you like that ?