Class: Jet::Type::Coercion

Inherits:
Object
  • Object
show all
Defined in:
lib/jet/type/coercion.rb

Instance Method Summary collapse

Constructor Details

#initialize(&blk) ⇒ Coercion

Returns a new instance of Coercion.

Raises:

  • (ArgumentError) 


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# File 'lib/jet/type/coercion.rb', line 6

def initialize(&blk)
  raise ArgumentError, "no block given" unless block_given?
  @checks = []
  @matchers = []
  instance_eval(&blk)
  raise ArgumentError, "no `match` blocks given" if @matchers.empty?
  @checks = @checks.freeze
  @matchers.freeze
  @transformer ||= proc { |input| input }
end

Instance Method Details

#call(input) ⇒ Object 



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# File 'lib/jet/type/coercion.rb', line 17

def call(input)
  return Result.failure(:no_coercion_match, input: input) unless match?(input)

  catch(:transformation_failure) do
    check_output(input, instance_exec(input, &@transformer))
  end
end

#check_output(input, output) ⇒ Object 



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# File 'lib/jet/type/coercion.rb', line 25

def check_output(input, output)
  @checks.each do |(check, error)|
    return coercion_check_failure(output, input, error) unless check.(output, input)
  end
  Result.success(output, input: input)
end

#coercion_check_failure(output, input, error) ⇒ Object 



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# File 'lib/jet/type/coercion.rb', line 32

def coercion_check_failure(output, input, error)
  Result.failure(:coercion_check_failure, errors: error, input: input, output: output)
end

#match?(output) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jet/type/coercion.rb', line 36

def match?(output)
  @matchers.any? { |blk| blk.(output) }
end

#transformation_failure(input, *errors) ⇒ Object 



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# File 'lib/jet/type/coercion.rb', line 40

def transformation_failure(input, *errors)
  Result.failure(:transformation_failure, errors: errors, input: input)
end

#transformation_failure!(*args) ⇒ Object 



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# File 'lib/jet/type/coercion.rb', line 44

def transformation_failure!(*args)
  throw :transformation_failure, transformation_failure(*args)
end