fix: correctly handle reading locked pact file on windows

The yielded file from Filelock must be read, rather than using File.read, otherwise "Permission denied @ io_fread" is raised.

Fixes: pact-foundation/pact-js#150

lib/pact/consumer_contract/consumer_contract_writer.rb

@@ -60,10 +60,15 @@ def update_pactfile_if_needed
  def update_pactfile
  logger.info log_message
  FileUtils.mkdir_p File.dirname(pactfile_path)
- Filelock pactfile_path do | file |
+ Filelock(pactfile_path) do | pact_file |
+ # must be read after obtaining the lock, and must be read from the yielded file object, otherwise windows freaks out
+ @existing_contents = pact_file.read
  new_contents = pact_json
- file.truncate 0
- file.write new_contents
+ pact_file.rewind
+ pact_file.truncate 0
+ pact_file.write new_contents
+ pact_file.flush
+ pact_file.truncate(pact_file.pos)
  end
  end
 
@@ -109,9 +114,12 @@ def pactfile_has_contents?
  File.size(pactfile_path) != 0
  end
 
+ def existing_contents
+ @existing_contents
+ end
+
  def existing_consumer_contract
- # This must only be read after the file has been locked
- Pact::ConsumerContract.from_uri(pactfile_path)
+ @existing_consumer_contract ||= Pact::ConsumerContract.from_json(existing_contents)
  end
 
  def warn_and_stderr msg

spec/lib/pact/consumer_contract/consumer_contract_writer_spec.rb

@@ -36,31 +36,36 @@ module Pact
 
  let(:consumer_contract_writer) { ConsumerContractWriter.new(consumer_contract_details, logger) }
 
- describe "consumer_contract" do
-
- let(:subject) { consumer_contract_writer.consumer_contract }
+ describe "#write" do
+ it "writes the pact file to the pact_dir" do
+ FileUtils.rm_rf target_pact_file_location
+ consumer_contract_writer.write
+ expect(File.exist?(target_pact_file_location)).to be true
+ end
 
  context "when overwriting pact" do
 
  it "it uses only the interactions from the current test run" do
- expect(consumer_contract_writer.consumer_contract.interactions).to eq new_interactions
+ consumer_contract_writer.write
+ expect(Pact::ConsumerContract.from_json(File.read(target_pact_file_location)).interactions.collect(&:to_hash)).to eq new_interactions.collect(&:to_hash)
  end
 
  end
 
  context "when updating pact" do
 
- let(:pactfile_write_mode) {:update}
+ let(:pactfile_write_mode) { :update }
 
  it "merges the interactions from the current test run with the interactions from the existing file" do
  allow_any_instance_of(ConsumerContractWriter).to receive(:info_and_puts)
- expect(consumer_contract_writer.consumer_contract.interactions).to eq existing_interactions + new_interactions
+ consumer_contract_writer.write
+ expect(Pact::ConsumerContract.from_uri(target_pact_file_location).interactions.size).to eq 3
  end
 
- let(:line0) { /\*/ }
- let(:line1) { /Updating existing file/ }
- let(:line2) { /Only interactions defined in this test run will be updated/ }
- let(:line3) { /As interactions are identified by description and provider state/ }
+ let(:line0) { "*" * 77 }
+ let(:line1) { %r{Updating existing file} }
+ let(:line2) { %r{Only interactions defined in this test run will be updated} }
+ let(:line3) { %r{As interactions are identified by description and provider state} }
 
  it "logs a description message" do
  expect($stdout).to receive(:puts).with(line0).twice
@@ -71,40 +76,37 @@ module Pact
  expect(logger).to receive(:info).with(line1)
  expect(logger).to receive(:info).with(line2)
  expect(logger).to receive(:info).with(line3)
- consumer_contract_writer.consumer_contract
+ consumer_contract_writer.write
  end
  end
 
  context "when an error occurs deserializing the existing pactfile" do
 
- let(:pactfile_write_mode) {:update}
+ let(:pactfile_write_mode) { :update }
  let(:error) { RuntimeError.new('some error')}
- let(:line1) { /Could not load existing consumer contract from .* due to some error/ }
+ let(:line1) { %r{Could not load existing consumer contract from .* due to} }
 
  before do
- allow(ConsumerContract).to receive(:from_json).and_raise(error)
+ File.open(target_pact_file_location, "w") { |file| file << "wiffle" }
+
  allow($stderr).to receive(:puts)
  allow(logger).to receive(:puts)
  end
 
+ after do
+ FileUtils.rm(target_pact_file_location)
+ end
+
  it "logs the error" do
  expect($stderr).to receive(:puts).with(line1)
  expect(logger).to receive(:warn).with(line1)
- consumer_contract_writer.consumer_contract
+ consumer_contract_writer.write
  end
 
  it "uses the new interactions" do
  expect(consumer_contract_writer.consumer_contract.interactions).to eq new_interactions
  end
  end
- end
-
- describe "#write" do
- it "writes the pact file to the pact_dir" do
- FileUtils.rm_rf target_pact_file_location
- consumer_contract_writer.write
- expect(File.exist?(target_pact_file_location)).to be true
- end
 
  context "when pactfile_write_mode is update" do
  let(:pactfile_write_mode) { :update }

spec/support/factories.rb

@@ -37,7 +37,7 @@ def self.create hash = {}
  },
  'response' => {
  'status' => 200,
- 'body' => {a: 'response body'}
+ 'body' => {'a' => 'response body'}
  }
  }
  Pact::Interaction.from_hash(stringify_keys(deep_merge(defaults, stringify_keys(hash))))