describe Appsignal::Transaction do
  before :context do
    start_agent
  end

  let(:transaction_id) { "1" }
  let(:time)           { Time.at(fixed_time) }
  let(:namespace)      { Appsignal::Transaction::HTTP_REQUEST }
  let(:env)            { {} }
  let(:merged_env)     { http_request_env_with_data(env) }
  let(:options)        { {} }
  let(:request)        { Rack::Request.new(merged_env) }
  let(:transaction)    { Appsignal::Transaction.new(transaction_id, namespace, request, options) }
  let(:log)            { StringIO.new }

  before { Timecop.freeze(time) }
  after { Timecop.return }
  around do |example|
    use_logger_with log do
      example.run
    end
  end

  describe "class methods" do
    def current_transaction
      Appsignal::Transaction.current
    end

    describe ".create" do
      def create_transaction(id = transaction_id)
        Appsignal::Transaction.create(id, namespace, request, options)
      end

      context "when no transaction is running" do
        let!(:transaction) { create_transaction }

        it "returns the created transaction" do
          expect(transaction).to be_a Appsignal::Transaction
          expect(transaction.transaction_id).to eq transaction_id
          expect(transaction.namespace).to eq namespace
          expect(transaction.request).to eq request

          expect(transaction.to_h).to include(
            "id" => transaction_id,
            "namespace" => namespace
          )
        end

        it "assigns the transaction to current" do
          expect(transaction).to eq current_transaction
        end
      end

      context "when a transaction is already running" do
        before { create_transaction }

        it "does not create a new transaction, but returns the current transaction" do
          expect do
            new_transaction = create_transaction("2")
            expect(new_transaction).to eq(current_transaction)
            expect(new_transaction.transaction_id).to eq(transaction_id)
          end.to_not(change { current_transaction })
        end

        it "logs a debug message" do
          create_transaction("2")
          expect(log_contents(log)).to contains_log :debug,
            "Trying to start new transaction with id '2', but a " \
            "transaction with id '#{transaction_id}' is already " \
            "running. Using transaction '#{transaction_id}'."
        end

        context "with option :force => true" do
          it "returns the newly created (and current) transaction" do
            original_transaction = current_transaction
            expect(original_transaction).to_not be_nil
            expect(current_transaction.transaction_id).to eq transaction_id

            options[:force] = true
            expect(create_transaction("2")).to_not eq original_transaction
            expect(current_transaction.transaction_id).to eq "2"
          end
        end
      end
    end

    describe ".current" do
      subject { Appsignal::Transaction.current }

      context "when there is a current transaction" do
        let!(:transaction) do
          Appsignal::Transaction.create(transaction_id, namespace, request, options)
        end

        it "reads :appsignal_transaction from the current Thread" do
          expect(subject).to eq Thread.current[:appsignal_transaction]
          expect(subject).to eq transaction
        end

        it "is not a NilTransaction" do
          expect(subject.nil_transaction?).to eq false
          expect(subject).to be_a Appsignal::Transaction
        end
      end

      context "when there is no current transaction" do
        it "has no :appsignal_transaction registered on the current Thread" do
          expect(Thread.current[:appsignal_transaction]).to be_nil
        end

        it "returns a NilTransaction stub" do
          expect(subject.nil_transaction?).to eq true
          expect(subject).to be_a Appsignal::Transaction::NilTransaction
        end
      end
    end

    describe ".complete_current!" do
      let!(:transaction) { Appsignal::Transaction.create(transaction_id, namespace, options) }

      it "completes the current transaction" do
        expect(transaction).to eq current_transaction
        expect(transaction).to receive(:complete).and_call_original

        Appsignal::Transaction.complete_current!
      end

      it "unsets the current transaction on the current Thread" do
        expect do
          Appsignal::Transaction.complete_current!
        end.to change { Thread.current[:appsignal_transaction] }.from(transaction).to(nil)
      end

      context "when encountering an error while completing" do
        before do
          expect(transaction).to receive(:complete).and_raise ExampleStandardError
        end

        it "logs an error message" do
          Appsignal::Transaction.complete_current!
          expect(log_contents(log)).to contains_log :error,
            "Failed to complete transaction ##{transaction.transaction_id}. ExampleStandardError"
        end

        it "clears the current transaction" do
          expect do
            Appsignal::Transaction.complete_current!
          end.to change { Thread.current[:appsignal_transaction] }.from(transaction).to(nil)
        end
      end
    end
  end

  describe "#complete" do
    context "when transaction is being sampled" do
      it "samples data" do
        expect(transaction.ext).to receive(:finish).and_return(true)
        # Stub call to extension, because that would remove the transaction
        # from the extension.
        expect(transaction.ext).to receive(:complete)

        transaction.set_tags(:foo => "bar")
        transaction.complete
        expect(transaction.to_h["sample_data"]).to include(
          "tags" => { "foo" => "bar" }
        )
      end
    end

    context "when transaction is not being sampled" do
      it "does not sample data" do
        expect(transaction).to_not receive(:sample_data)
        expect(transaction.ext).to receive(:finish).and_return(false)
        expect(transaction.ext).to receive(:complete).and_call_original

        transaction.complete
      end
    end

    context "when a transaction is marked as discarded" do
      it "does not complete the transaction" do
        expect(transaction.ext).to_not receive(:complete)

        expect do
          transaction.discard!
        end.to change { transaction.discarded? }.from(false).to(true)

        transaction.complete
      end

      it "logs a debug message" do
        transaction.discard!
        transaction.complete

        expect(log_contents(log)).to contains_log :debug,
          "Skipping transaction '#{transaction_id}' because it was manually discarded."
      end

      context "when a discarded transaction is restored" do
        before { transaction.discard! }

        it "completes the transaction" do
          expect(transaction.ext).to receive(:complete).and_call_original

          expect do
            transaction.restore!
          end.to change { transaction.discarded? }.from(true).to(false)

          transaction.complete
        end
      end
    end
  end

  context "pausing" do
    describe "#pause!" do
      it "changes the pause flag to true" do
        expect do
          transaction.pause!
        end.to change(transaction, :paused).from(false).to(true)
      end
    end

    describe "#resume!" do
      before { transaction.pause! }

      it "changes the pause flag to false" do
        expect do
          transaction.resume!
        end.to change(transaction, :paused).from(true).to(false)
      end
    end

    describe "#paused?" do
      context "when not paused" do
        it "return false" do
          expect(transaction.paused?).to be_falsy
        end
      end

      context "when paused" do
        before { transaction.pause! }

        it "returns true" do
          expect(transaction.paused?).to be_truthy
        end
      end
    end
  end

  context "with transaction instance" do
    context "initialization" do
      it "loads the AppSignal extension" do
        expect(transaction.ext).to_not be_nil
      end

      it "sets the transaction id" do
        expect(transaction.transaction_id).to eq "1"
      end

      it "sets the namespace to http_request" do
        expect(transaction.namespace).to eq "http_request"
      end

      it "sets the request" do
        expect(transaction.request).to_not be_nil
      end

      it "sets the request not to paused" do
        expect(transaction.paused).to be_falsy
      end

      it "sets no tags by default" do
        expect(transaction.tags).to eq({})
      end

      describe "#options" do
        subject { transaction.options }

        it "sets the default :params_method" do
          expect(subject[:params_method]).to eq :params
        end

        context "with overridden options" do
          let(:options) { { :params_method => :filtered_params } }

          it "sets the overriden :params_method" do
            expect(subject[:params_method]).to eq :filtered_params
          end
        end
      end
    end

    describe "#store" do
      it "should return an empty store when it's not already present" do
        expect(transaction.store("test")).to eql({})
      end

      it "should store changes to the store" do
        transaction_store = transaction.store("test")
        transaction_store["transaction"] = "value"

        expect(transaction.store("test")).to eql("transaction" => "value")
      end
    end

    describe "#params" do
      subject { transaction.params }

      context "with custom params set on transaction" do
        before do
          transaction.params = { :foo => "bar" }
        end

        it "returns custom parameters" do
          expect(subject).to eq(:foo => "bar")
        end
      end

      context "without custom params set on transaction" do
        it "returns parameters from request" do
          expect(subject).to eq(
            "action" => "show",
            "controller" => "blog_posts",
            "id" => "1"
          )
        end
      end
    end

    describe "#params=" do
      it "sets params on the transaction" do
        transaction.params = { :foo => "bar" }
        expect(transaction.params).to eq(:foo => "bar")
      end
    end

    describe "#set_tags" do
      let(:long_string) { "a" * 2001 }
      before do
        transaction.set_tags(
          :valid_key => "valid_value",
          "valid_string_key" => "valid_value",
          :both_symbols => :valid_value,
          :integer_value => 1,
          :hash_value => { "invalid" => "hash" },
          :array_value => %w[invalid array],
          :object => Object.new,
          :too_long_value => long_string,
          long_string => "too_long_key"
        )
        transaction.sample_data
      end

      it "stores tags on the transaction" do
        expect(transaction.to_h["sample_data"]["tags"]).to eq(
          "valid_key" => "valid_value",
          "valid_string_key" => "valid_value",
          "both_symbols" => "valid_value",
          "integer_value" => 1,
          "too_long_value" => "#{"a" * 2000}...",
          long_string => "too_long_key"
        )
      end
    end

    describe "#set_action" do
      context "when the action is set" do
        it "updates the action name on the transaction" do
          action_name = "PagesController#show"
          transaction.set_action(action_name)

          expect(transaction.action).to eq(action_name)
          expect(transaction.to_h["action"]).to eq(action_name)
        end
      end

      context "when the action is nil" do
        it "does not update the action name on the transaction" do
          action_name = "PagesController#show"
          transaction.set_action(action_name)
          transaction.set_action(nil)

          expect(transaction.action).to eq(action_name)
          expect(transaction.to_h["action"]).to eq(action_name)
        end
      end
    end

    describe "#set_action_if_nil" do
      context "when the action is not set" do
        it "updates the action name on the transaction" do
          expect(transaction.action).to eq(nil)
          expect(transaction.to_h["action"]).to eq(nil)

          action_name = "PagesController#show"
          transaction.set_action_if_nil(action_name)

          expect(transaction.action).to eq(action_name)
          expect(transaction.to_h["action"]).to eq(action_name)
        end

        context "when the given action is nil" do
          it "does not update the action name on the transaction" do
            action_name = "something"
            transaction.set_action("something")
            transaction.set_action_if_nil(nil)

            expect(transaction.action).to eq(action_name)
            expect(transaction.to_h["action"]).to eq(action_name)
          end
        end
      end

      context "when the action is set" do
        it "does not update the action name on the transaction" do
          action_name = "something"
          transaction.set_action("something")
          transaction.set_action_if_nil("something else")

          expect(transaction.action).to eq(action_name)
          expect(transaction.to_h["action"]).to eq(action_name)
        end
      end
    end

    describe "#set_namespace" do
      context "when the namespace is not nil" do
        it "updates the namespace on the transaction" do
          namespace = "custom"
          transaction.set_namespace(namespace)

          expect(transaction.namespace).to eq namespace
          expect(transaction.to_h["namespace"]).to eq(namespace)
        end
      end

      context "when the namespace is nil" do
        it "does not update the namespace on the transaction" do
          namespace = "custom"
          transaction.set_namespace(namespace)
          transaction.set_namespace(nil)

          expect(transaction.namespace).to eq(namespace)
          expect(transaction.to_h["namespace"]).to eq(namespace)
        end
      end
    end

    describe "#set_http_or_background_action" do
      context "for a hash with controller and action" do
        let(:from) { { :controller => "HomeController", :action => "show" } }

        it "should set the action" do
          expect(transaction).to receive(:set_action).with("HomeController#show")
        end
      end

      context "for a hash with just action" do
        let(:from) { { :action => "show" } }

        it "should set the action" do
          expect(transaction).to receive(:set_action).with("show")
        end
      end

      context "for a hash with class and method" do
        let(:from) { { :class => "Worker", :method => "perform" } }

        it "should set the action" do
          expect(transaction).to receive(:set_action).with("Worker#perform")
        end
      end

      after { transaction.set_http_or_background_action(from) }
    end

    describe "set_queue_start" do
      it "should set the queue start in extension" do
        expect(transaction.ext).to receive(:set_queue_start).with(
          10.0
        ).once

        transaction.set_queue_start(10.0)
      end

      it "should not set the queue start in extension when value is nil" do
        expect(transaction.ext).to_not receive(:set_queue_start)

        transaction.set_queue_start(nil)
      end

      it "should not raise an error when the queue start is too big" do
        expect(transaction.ext).to receive(:set_queue_start).and_raise(RangeError)

        expect(Appsignal.logger).to receive(:warn).with("Queue start value 10 is too big")

        expect do
          transaction.set_queue_start(10)
        end.to_not raise_error
      end
    end

    describe "#set_http_or_background_queue_start" do
      context "for a http transaction" do
        let(:namespace) { Appsignal::Transaction::HTTP_REQUEST }
        let(:env) { { "HTTP_X_REQUEST_START" => (fixed_time * 1000).to_s } }

        it "should set the queue start on the transaction" do
          expect(transaction).to receive(:set_queue_start).with(13_897_836_000)

          transaction.set_http_or_background_queue_start
        end
      end

      context "for a background transaction" do
        let(:namespace) { Appsignal::Transaction::BACKGROUND_JOB }
        let(:env) { { :queue_start => fixed_time } }

        it "should set the queue start on the transaction" do
          expect(transaction).to receive(:set_queue_start).with(1_389_783_600_000)

          transaction.set_http_or_background_queue_start
        end
      end
    end

    describe "#set_metadata" do
      it "updates the metadata on the transaction" do
        transaction.set_metadata("request_method", "GET")

        expect(transaction.to_h["metadata"]).to eq("request_method" => "GET")
      end

      context "when the key is nil" do
        it "does not update the metadata on the transaction" do
          transaction.set_metadata(nil, "GET")

          expect(transaction.to_h["metadata"]).to eq({})
        end
      end

      context "when the value is nil" do
        it "does not update the metadata on the transaction" do
          transaction.set_metadata("request_method", nil)

          expect(transaction.to_h["metadata"]).to eq({})
        end
      end
    end

    describe "#set_sample_data" do
      it "updates the sample data on the transaction" do
        transaction.set_sample_data(
          "params",
          :controller => "blog_posts",
          :action     => "show",
          :id         => "1"
        )

        expect(transaction.to_h["sample_data"]).to eq(
          "params" => {
            "action" => "show",
            "controller" => "blog_posts",
            "id" => "1"
          }
        )
      end

      context "when the data is no Array or Hash" do
        it "does not update the sample data on the transaction" do
          transaction.set_sample_data("params", "string")

          expect(transaction.to_h["sample_data"]).to eq({})
        end
      end

      context "when the data cannot be converted to JSON" do
        it "does not update the sample data on the transaction" do
          klass = Class.new do
            def to_s
              raise "foo" # Cause a deliberate error
            end
          end
          transaction.set_sample_data("params", klass.new => 1)

          expect(transaction.to_h["sample_data"]).to eq({})
          expect(log_contents(log)).to contains_log :error,
            "Error generating data (RuntimeError: foo) for"
        end
      end
    end

    describe "#sample_data" do
      it "should sample data" do
        expect(transaction.ext).to receive(:set_sample_data).with(
          "environment",
          Appsignal::Utils::Data.generate(
            "CONTENT_LENGTH" => "0",
            "REQUEST_METHOD" => "GET",
            "SERVER_NAME" => "example.org",
            "SERVER_PORT" => "80",
            "PATH_INFO" => "/blog"
          )
        ).once
        expect(transaction.ext).to receive(:set_sample_data).with(
          "session_data",
          Appsignal::Utils::Data.generate({})
        ).once
        expect(transaction.ext).to receive(:set_sample_data).with(
          "params",
          Appsignal::Utils::Data.generate(
            "controller" => "blog_posts",
            "action" => "show",
            "id" => "1"
          )
        ).once
        expect(transaction.ext).to receive(:set_sample_data).with(
          "metadata",
          Appsignal::Utils::Data.generate("key" => "value")
        ).once
        expect(transaction.ext).to receive(:set_sample_data).with(
          "tags",
          Appsignal::Utils::Data.generate({})
        ).once

        transaction.sample_data
      end
    end

    describe "#set_error" do
      let(:env) { http_request_env_with_data }
      let(:error) { double(:error, :message => "test message", :backtrace => ["line 1"]) }

      it "should also respond to add_exception for backwords compatibility" do
        expect(transaction).to respond_to(:add_exception)
      end

      it "should not add the error if appsignal is not active" do
        allow(Appsignal).to receive(:active?).and_return(false)
        expect(transaction.ext).to_not receive(:set_error)

        transaction.set_error(error)
      end

      context "for a http request" do
        it "should set an error in the extension" do
          expect(transaction.ext).to receive(:set_error).with(
            "RSpec::Mocks::Double",
            "test message",
            Appsignal::Utils::Data.generate(["line 1"])
          )

          transaction.set_error(error)
        end
      end

      context "when error message is nil" do
        let(:error) { double(:error, :message => nil, :backtrace => ["line 1"]) }

        it "should not raise an error" do
          expect { transaction.set_error(error) }.to_not raise_error
        end

        it "should set an error in the extension" do
          expect(transaction.ext).to receive(:set_error).with(
            "RSpec::Mocks::Double",
            "",
            Appsignal::Utils::Data.generate(["line 1"])
          )

          transaction.set_error(error)
        end
      end
    end

    describe "#garbage_collection_profiler" do
      before { Appsignal::Transaction.instance_variable_set(:@garbage_collection_profiler, nil) }

      it "returns the NilGarbageCollectionProfiler" do
        expect(Appsignal::Transaction.garbage_collection_profiler).to be_a(Appsignal::NilGarbageCollectionProfiler)
      end

      context "when gc profiling is enabled" do
        before { Appsignal.config.config_hash[:enable_gc_instrumentation] = true }
        after { Appsignal.config.config_hash[:enable_gc_instrumentation] = false }

        it "returns the GarbageCollectionProfiler" do
          expect(Appsignal::Transaction.garbage_collection_profiler).to be_a(Appsignal::GarbageCollectionProfiler)
        end
      end
    end

    describe "#start_event" do
      it "starts the event in the extension" do
        expect(transaction.ext).to receive(:start_event).with(0).and_call_original

        transaction.start_event
      end

      context "when transaction is paused" do
        it "does not start the event" do
          transaction.pause!
          expect(transaction.ext).to_not receive(:start_event)

          transaction.start_event
        end
      end
    end

    describe "#finish_event" do
      let(:fake_gc_time) { 123 }
      before do
        expect(described_class.garbage_collection_profiler)
          .to receive(:total_time).at_least(:once).and_return(fake_gc_time)
      end

      it "should finish the event in the extension" do
        expect(transaction.ext).to receive(:finish_event).with(
          "name",
          "title",
          "body",
          1,
          fake_gc_time
        ).and_call_original

        transaction.finish_event(
          "name",
          "title",
          "body",
          1
        )
      end

      it "should finish the event in the extension with nil arguments" do
        expect(transaction.ext).to receive(:finish_event).with(
          "name",
          "",
          "",
          0,
          fake_gc_time
        ).and_call_original

        transaction.finish_event(
          "name",
          nil,
          nil,
          nil
        )
      end

      context "when transaction is paused" do
        it "does not finish the event" do
          transaction.pause!
          expect(transaction.ext).to_not receive(:finish_event)

          transaction.start_event
        end
      end
    end

    describe "#record_event" do
      let(:fake_gc_time) { 123 }
      before do
        expect(described_class.garbage_collection_profiler)
          .to receive(:total_time).at_least(:once).and_return(fake_gc_time)
      end

      it "should record the event in the extension" do
        expect(transaction.ext).to receive(:record_event).with(
          "name",
          "title",
          "body",
          1,
          1000,
          fake_gc_time
        ).and_call_original

        transaction.record_event(
          "name",
          "title",
          "body",
          1000,
          1
        )
      end

      it "should finish the event in the extension with nil arguments" do
        expect(transaction.ext).to receive(:record_event).with(
          "name",
          "",
          "",
          0,
          1000,
          fake_gc_time
        ).and_call_original

        transaction.record_event(
          "name",
          nil,
          nil,
          1000,
          nil
        )
      end

      context "when transaction is paused" do
        it "does not record the event" do
          transaction.pause!
          expect(transaction.ext).to_not receive(:record_event)

          transaction.record_event(
            "name",
            nil,
            nil,
            1000,
            nil
          )
        end
      end
    end

    describe "#instrument" do
      it_behaves_like "instrument helper" do
        let(:instrumenter) { transaction }
      end
    end

    context "generic request" do
      let(:env) { {} }
      subject { Appsignal::Transaction::GenericRequest.new(env) }

      it "initializes with an empty env" do
        expect(subject.env).to be_empty
      end

      context "when given an env" do
        let(:env) do
          {
            :params => { :id => 1 },
            :queue_start => 10
          }
        end

        it "sets the given env" do
          expect(subject.env).to eq env
        end

        it "sets the params present in the env" do
          expect(subject.params).to eq(:id => 1)
        end
      end
    end

    # private

    describe "#background_queue_start" do
      subject { transaction.send(:background_queue_start) }

      context "when request is nil" do
        let(:request) { nil }

        it { is_expected.to eq nil }
      end

      context "when env is nil" do
        before { expect(transaction.request).to receive(:env).and_return(nil) }

        it { is_expected.to eq nil }
      end

      context "when queue start is nil" do
        it { is_expected.to eq nil }
      end

      context "when queue start is set" do
        let(:env) { background_env_with_data }

        it { is_expected.to eq 1_389_783_590_000 }
      end
    end

    describe "#http_queue_start" do
      let(:slightly_earlier_time) { fixed_time - 0.4 }
      let(:slightly_earlier_time_value) { (slightly_earlier_time * factor).to_i }
      subject { transaction.send(:http_queue_start) }

      shared_examples "http queue start" do
        context "when request is nil" do
          let(:request) { nil }

          it { is_expected.to be_nil }
        end

        context "when env is nil" do
          before { expect(transaction.request).to receive(:env).and_return(nil) }

          it { is_expected.to be_nil }
        end

        context "with no relevant header set" do
          let(:env) { {} }

          it { is_expected.to be_nil }
        end

        context "with the HTTP_X_REQUEST_START header set" do
          let(:env) { { "HTTP_X_REQUEST_START" => "t=#{slightly_earlier_time_value}" } }

          it { is_expected.to eq 1_389_783_599_600 }

          context "with unparsable content" do
            let(:env) { { "HTTP_X_REQUEST_START" => "something" } }

            it { is_expected.to be_nil }
          end

          context "with some cruft" do
            let(:env) { { "HTTP_X_REQUEST_START" => "t=#{slightly_earlier_time_value}aaaa" } }

            it { is_expected.to eq 1_389_783_599_600 }
          end

          context "with a really low number" do
            let(:env) { { "HTTP_X_REQUEST_START" => "t=100" } }

            it { is_expected.to be_nil }
          end

          context "with the alternate HTTP_X_QUEUE_START header set" do
            let(:env) { { "HTTP_X_QUEUE_START" => "t=#{slightly_earlier_time_value}" } }

            it { is_expected.to eq 1_389_783_599_600 }
          end
        end
      end

      context "time in miliseconds" do
        let(:factor) { 1_000 }

        it_should_behave_like "http queue start"
      end

      context "time in microseconds" do
        let(:factor) { 1_000_000 }

        it_should_behave_like "http queue start"
      end
    end

    describe "#sanitized_params" do
      subject { transaction.send(:sanitized_params) }

      context "with custom params" do
        before do
          transaction.params = { :foo => "bar", :baz => :bat }
        end

        it "returns custom params" do
          is_expected.to eq(:foo => "bar", :baz => :bat)
        end

        context "with AppSignal filtering" do
          before { Appsignal.config.config_hash[:filter_parameters] = %w[foo] }
          after { Appsignal.config.config_hash[:filter_parameters] = [] }

          it "returns sanitized custom params" do
            expect(subject).to eq(:foo => "[FILTERED]", :baz => :bat)
          end
        end
      end

      context "without request params" do
        before { allow(transaction.request).to receive(:params).and_return(nil) }

        it { is_expected.to be_nil }
      end

      context "when request params crashes" do
        before { allow(transaction.request).to receive(:params).and_raise(NoMethodError) }

        it { is_expected.to be_nil }
      end

      context "when request params method does not exist" do
        let(:options) { { :params_method => :nonsense } }

        it { is_expected.to be_nil }
      end

      context "when not sending params" do
        before { Appsignal.config.config_hash[:send_params] = false }
        after { Appsignal.config.config_hash[:send_params] = true }

        it { is_expected.to be_nil }
      end

      context "with an array" do
        let(:request) do
          Appsignal::Transaction::GenericRequest.new(background_env_with_data(:params => %w[arg1 arg2]))
        end

        it { is_expected.to eq %w[arg1 arg2] }

        context "with AppSignal filtering" do
          before { Appsignal.config.config_hash[:filter_parameters] = %w[foo] }
          after { Appsignal.config.config_hash[:filter_parameters] = [] }

          it { is_expected.to eq %w[arg1 arg2] }
        end
      end

      context "with env" do
        context "with sanitization" do
          let(:request) do
            Appsignal::Transaction::GenericRequest.new \
              http_request_env_with_data(:params => { :foo => :bar })
          end

          it "should call the params sanitizer" do
            expect(subject).to eq(:foo => :bar)
          end
        end

        context "with AppSignal filtering" do
          let(:request) do
            Appsignal::Transaction::GenericRequest.new \
              http_request_env_with_data(:params => { :foo => :bar, :baz => :bat })
          end
          before { Appsignal.config.config_hash[:filter_parameters] = %w[foo] }
          after { Appsignal.config.config_hash[:filter_parameters] = [] }

          it "should call the params sanitizer with filtering" do
            expect(subject).to eq(:foo => "[FILTERED]", :baz => :bat)
          end
        end
      end
    end

    describe "#sanitized_environment" do
      let(:allowlisted_keys) { Appsignal.config[:request_headers] }
      subject { transaction.send(:sanitized_environment) }

      context "when request is nil" do
        let(:request) { nil }

        it { is_expected.to be_nil }
      end

      context "when env is nil" do
        before { expect(transaction.request).to receive(:env).and_return(nil) }

        it { is_expected.to be_nil }
      end

      context "when env is present" do
        let(:env) do
          {}.tap do |hash|
            allowlisted_keys.each { |o| hash[o] = 1 } # use all allowlisted keys
            hash[allowlisted_keys] = nil # don't add if nil
            hash[:not_allowlisted] = "I will be sanitized"
          end
        end

        it "only sets allowlisted keys" do
          expect(subject.keys).to match_array(allowlisted_keys)
        end

        context "with configured request_headers" do
          before do
            Appsignal.config.config_hash[:request_headers] = %w[CONTENT_LENGTH]
          end

          it "only sets allowlisted keys" do
            expect(subject.keys).to match_array(%w[CONTENT_LENGTH])
          end
        end
      end
    end

    describe "#sanitized_session_data" do
      subject { transaction.send(:sanitized_session_data) }

      context "when request is nil" do
        let(:request) { nil }

        it { is_expected.to be_nil }
      end

      context "when session is nil" do
        before { expect(transaction.request).to receive(:session).and_return(nil) }

        it { is_expected.to be_nil }
      end

      context "when session is empty" do
        before { expect(transaction.request).to receive(:session).and_return({}) }

        it { is_expected.to eq({}) }
      end

      context "when request class does not have a session method" do
        let(:request) { Appsignal::Transaction::GenericRequest.new({}) }

        it { is_expected.to be_nil }
      end

      context "with a session" do
        let(:session_data_filter) { [] }
        before { Appsignal.config[:filter_session_data] = session_data_filter }
        after { Appsignal.config[:filter_session_data] = [] }

        context "with generic session object" do
          before do
            expect(transaction).to respond_to(:request)
            allow(transaction).to receive_message_chain(
              :request,
              :session => { :foo => :bar, :abc => :def }
            )
            allow(transaction).to receive_message_chain(:request, :fullpath => :bar)
          end

          context "without session filtering" do
            it "keeps the session data intact" do
              expect(subject).to eq(:foo => :bar, :abc => :def)
            end
          end

          context "with session filtering" do
            let(:session_data_filter) { %w[foo] }

            it "filters the session data" do
              expect(subject).to eq(:foo => "[FILTERED]", :abc => :def)
            end
          end
        end

        if defined? ActionDispatch::Request::Session
          context "with ActionDispatch::Request::Session" do
            let(:action_dispatch_session) do
              store = Class.new do
                def load_session(_env)
                  [1, { :foo => :bar, :abc => :def }]
                end

                def session_exists?(_env)
                  true
                end
              end.new
              ActionDispatch::Request::Session.create(store, ActionDispatch::Request.new("rack.input" => StringIO.new), {})
            end
            before do
              expect(transaction).to respond_to(:request)
              allow(transaction).to receive_message_chain(
                :request,
                :session => action_dispatch_session
              )
              allow(transaction).to receive_message_chain(:request, :fullpath => :bar)
            end

            context "without session filtering" do
              it "keeps the session data intact" do
                expect(subject).to eq("foo" => :bar, "abc" => :def)
              end
            end

            context "with session filtering" do
              let(:session_data_filter) { %w[foo] }

              it "filters the session data" do
                expect(subject).to eq("foo" => "[FILTERED]", "abc" => :def)
              end
            end
          end
        end

        context "when skipping session data" do
          before { Appsignal.config[:skip_session_data] = true }

          it "does not set any session data on the transaction" do
            expect(subject).to be_nil
          end
        end
      end
    end

    describe "#metadata" do
      subject { transaction.send(:metadata) }

      context "when request is nil" do
        let(:request) { nil }

        it { is_expected.to be_nil }
      end

      context "when env is nil" do
        before { expect(transaction.request).to receive(:env).and_return(nil) }

        it { is_expected.to be_nil }
      end

      context "when env is present" do
        let(:env) { { :metadata => { :key => "value" } } }

        it { is_expected.to eq env[:metadata] }
      end
    end

    describe "#cleaned_backtrace" do
      subject { transaction.send(:cleaned_backtrace, ["line 1", "line 2"]) }

      it "returns the backtrace" do
        expect(subject).to eq ["line 1", "line 2"]
      end

      if rails_present?
        context "with rails" do
          it "cleans the backtrace with the Rails backtrace cleaner" do
            ::Rails.backtrace_cleaner.add_filter do |line|
              line.tr("2", "?")
            end
            expect(subject).to eq ["line 1", "line ?"]
          end
        end
      end
    end
  end

  describe ".to_hash / .to_h" do
    subject { transaction.to_hash }

    context "when extension returns serialized JSON" do
      it "parses the result and returns a Hash" do
        expect(subject).to include(
          "action" => nil,
          "error" => nil,
          "events" => [],
          "id" => transaction_id,
          "metadata" => {},
          "namespace" => namespace,
          "sample_data" => {}
        )
      end
    end

    context "when the extension returns invalid serialized JSON" do
      before do
        expect(transaction.ext).to receive(:to_json).and_return("foo")
      end

      it "raises a JSON parse error" do
        expect { subject }.to raise_error(JSON::ParserError)
      end
    end
  end

  describe Appsignal::Transaction::NilTransaction do
    subject { Appsignal::Transaction::NilTransaction.new }

    it "should have method stubs" do
      expect do
        subject.complete
        subject.pause!
        subject.resume!
        subject.paused?
        subject.store(:key)
        subject.set_tags(:tag => 1)
        subject.set_action("action")
        subject.set_http_or_background_action
        subject.set_queue_start(1)
        subject.set_http_or_background_queue_start
        subject.set_metadata("key", "value")
        subject.set_sample_data("key", "data")
        subject.sample_data
        subject.set_error("a")
      end.to_not raise_error
    end
  end
end