NoMethodError is raised when validating non-hash objects with a Dry::Validation::Contract that has config.validate_keys set to true

[tanyongkee]

Describe the bug

NoMethodError is raised when validating non-hash objects with a Dry::Validation::Contract that has config.validate_keys set to true.

Example

To Reproduce

class TestContract < Dry::Validation::Contract
  config.validate_keys = true
  json do
    required(:name).value(:hash) do
      optional(:title).filled(:string)
    end
  end
end

TestContract.new.call(1)

NoMethodError: undefined method `flat_map' for 1:Integer

        hash.flat_map { |key, value|
            ^^^^^^^^^

Expected behavior

=> #<Dry::Validation::Result{} errors={:name=>["is missing"]}>

The expected behavior is observed when config.validate_keys = false

My environment

• Affects my production application: NO
• Ruby version: 3.1.0
• OS: MAC OS M1

[solnic]

I couldn't reproduce it with dry-validation 1.9.0 and dry-schema 1.11.2

class TestContract < Dry::Validation::Contract
  config.validate_keys = true
  json do
    required(:name).value(:hash) do
      optional(:title).filled(:string)
    end
  end
end

TestContract.new.call(name: nil)
# => #<Dry::Validation::Result{:name=>nil} errors={:name=>["must be a hash"]}>

TestContract.new.call(name: 1)
# => #<Dry::Validation::Result{:name=>1} errors={:name=>["must be a hash"]}>

[timriley]

@solnic I think the problem raised initially is if the contract is called with a non-hash value:

TestContract.new.call(1)

Of course, that's nonsensical usage for the structure of the contract we've been discussing here.

I wonder if we should raise a more meaningful error earlier in the call stack rather than waiting for a NoMethodError about flat_map?

[solnic]

Oh right. Thanks Tim. I'm pretty sure it happens regardless of the validate_keys setting though. dry-schema doesn't check the input and assumes you passed in a hash. We could change it to only expect a hash and raise a meaningful error in case of non-hash values.

[bryszard]

Can the issue be closed?