Class: GraphQL::Stitching::Executor::ResolverSource

Inherits:
Dataloader::Source
  • Object
show all
Defined in:
lib/graphql/stitching/executor/resolver_source.rb

Instance Method Summary collapse

Constructor Details

#initialize(executor, location) ⇒ ResolverSource

Returns a new instance of ResolverSource.



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 6

def initialize(executor, location)
  @executor = executor
  @location = location
  @variables = {}
end

Instance Method Details

#build_document(origin_sets_by_operation, operation_name = nil, operation_directives = nil) ⇒ Object

Builds batched resolver queries "query MyOperation_2_3($var:VarType, $_0_key:[ID!]!, $_1_0_key:ID!, $_1_1_key:ID!, $_1_2_key:ID!) { _0_result: list(keys: $_0_key) { resolverSelections... } _1_0_result: item(key: $_1_0_key) { resolverSelections... } _1_1_result: item(key: $_1_1_key) { resolverSelections... } _1_2_result: item(key: $_1_2_key) { resolverSelections... } }"



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 52

def build_document(origin_sets_by_operation, operation_name = nil, operation_directives = nil)
  variable_defs = {}
  query_fields = origin_sets_by_operation.map.with_index do |(op, origin_set), batch_index|
    variable_defs.merge!(op.variables)
    resolver = op.resolver

    if resolver.list?
      variable_name = "_#{batch_index}_key"

      @variables[variable_name] = origin_set.map do |origin_obj|
        build_key(resolver.key, origin_obj, as_representation: resolver.representations?)
      end

      variable_defs[variable_name] = "[#{resolver.arg_type_name}!]!"
      "_#{batch_index}_result: #{resolver.field}(#{resolver.arg}:$#{variable_name}) #{op.selections}"
    else
      origin_set.map.with_index do |origin_obj, index|
        variable_name = "_#{batch_index}_#{index}_key"
        @variables[variable_name] = build_key(resolver.key, origin_obj, as_representation: resolver.representations?)

        variable_defs[variable_name] = "#{resolver.arg_type_name}!"
        "_#{batch_index}_#{index}_result: #{resolver.field}(#{resolver.arg}:$#{variable_name}) #{op.selections}"
      end
    end
  end

  doc = String.new("query") # << resolver fulfillment always uses query

  if operation_name
    doc << " #{operation_name}"
    origin_sets_by_operation.each_key do |op|
      doc << "_#{op.step}"
    end
  end

  if variable_defs.any?
    variable_str = variable_defs.map { |k, v| "$#{k}:#{v}" }.join(",")
    doc << "(#{variable_str})"
  end

  if operation_directives
    doc << " #{operation_directives} "
  end

  doc << "{ #{query_fields.join(" ")} }"

  return doc, variable_defs.keys.tap do |names|
    names.reject! { @variables.key?(_1) }
  end
end

#build_key(key, origin_obj, as_representation: false) ⇒ Object 



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 103

def build_key(key, origin_obj, as_representation: false)
  if as_representation
    {
      "__typename" => origin_obj[ExportSelection.typename_node.alias],
      key => origin_obj[ExportSelection.key(key)],
    }
  else
    origin_obj[ExportSelection.key(key)]
  end
end

#extract_errors!(origin_sets_by_operation, errors) ⇒ Object

https://spec.graphql.org/June2018/#sec-Errors



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 133

def extract_errors!(origin_sets_by_operation, errors)
  ops = origin_sets_by_operation.keys
  origin_sets = origin_sets_by_operation.values
  pathed_errors_by_op_index_and_object_id = {}

  errors_result = errors.each_with_object([]) do |err, memo|
    err.delete("locations")
    path = err["path"]

    if path && path.length > 0
      result_alias = /^_(\d+)(?:_(\d+))?_result$/.match(path.first.to_s)

      if result_alias
        path = err["path"] = path[1..-1]

        origin_obj = if result_alias[2]
          origin_sets.dig(result_alias[1].to_i, result_alias[2].to_i)
        elsif path[0].is_a?(Integer) || /\d+/.match?(path[0].to_s)
          origin_sets.dig(result_alias[1].to_i, path.shift.to_i)
        end

        if origin_obj
          by_op_index = pathed_errors_by_op_index_and_object_id[result_alias[1].to_i] ||= {}
          by_object_id = by_op_index[origin_obj.object_id] ||= []
          by_object_id << err
          next
        end
      end
    end

    memo << err
  end

  if pathed_errors_by_op_index_and_object_id.any?
    pathed_errors_by_op_index_and_object_id.each do |op_index, pathed_errors_by_object_id|
      repath_errors!(pathed_errors_by_object_id, ops.dig(op_index, "path"))
      errors_result.concat(pathed_errors_by_object_id.values)
    end
  end

  errors_result.tap(&:flatten!)
end

#fetch(ops) ⇒ Object 



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 12

def fetch(ops)
  origin_sets_by_operation = ops.each_with_object({}) do |op, memo|
    origin_set = op.path.reduce([@executor.data]) do |set, path_segment|
      set.flat_map { |obj| obj && obj[path_segment] }.tap(&:compact!)
    end

    if op.if_type
      # operations planned around unused fragment conditions should not trigger requests
      origin_set.select! { _1[ExportSelection.typename_node.alias] == op.if_type }
    end

    memo[op] = origin_set if origin_set.any?
  end

  if origin_sets_by_operation.any?
    query_document, variable_names = build_document(
      origin_sets_by_operation,
      @executor.request.operation_name,
      @executor.request.operation_directives,
    )
    variables = @variables.merge!(@executor.request.variables.slice(*variable_names))
    raw_result = @executor.request.supergraph.execute_at_location(@location, query_document, variables, @executor.request)
    @executor.query_count += 1

    merge_results!(origin_sets_by_operation, raw_result.dig("data"))

    errors = raw_result.dig("errors")
    @executor.errors.concat(extract_errors!(origin_sets_by_operation, errors)) if errors&.any?
  end

  ops.map { origin_sets_by_operation[_1] ? _1.step : nil }
end

#merge_results!(origin_sets_by_operation, raw_result) ⇒ Object 



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# File 'lib/graphql/stitching/executor/resolver_source.rb', line 114

def merge_results!(origin_sets_by_operation, raw_result)
  return unless raw_result

  origin_sets_by_operation.each_with_index do |(op, origin_set), batch_index|
    results = if op.resolver.list?
      raw_result["_#{batch_index}_result"]
    else
      origin_set.map.with_index { |_, index| raw_result["_#{batch_index}_#{index}_result"] }
    end

    next unless results&.any?

    origin_set.each_with_index do |origin_obj, index|
      origin_obj.merge!(results[index]) if results[index]
    end
  end
end