Stop stubbing Gzip compression

Author: AliSoftware

spec/ios_send_app_size_metrics_spec.rb

@@ -1,19 +1,5 @@
 require_relative './spec_helper'
 
-# A test double to mock the Gzip compression and keep the 'fake-compressed' result readable in test failures
-class GzipWriterDouble < StringIO
-  GZIP_PREFIX = '$GZIP$:'.freeze
-  def close
-    super
-    # `GzipWriter#close` returns `self` after closing (allowing use to use method chaining), unlike `StringIO#close`
-    self
-  end
-
-  def string
-    "#{GZIP_PREFIX}#{super}"
-  end
-end
-
 describe Fastlane::Actions::IosSendAppSizeMetricsAction do
   let(:test_data_dir) { File.join(File.dirname(__FILE__), 'test-data', 'app_size_metrics') }
   let(:mocked_endpoint) { 'https://localhost/api/metrics' }
@@ -22,7 +8,7 @@ def string
   # Utility method to turn a minified JSON into a pretty-formatted JSON (without the GZIP fake prefix if any)
   # To make any test failure and diff easier to debug
   def pretty_json(json_string)
-    JSON.pretty_generate(JSON.parse(json_string.delete_prefix(GzipWriterDouble::GZIP_PREFIX)))
+    JSON.pretty_generate(JSON.parse(json_string))
   end
 
   def test_app_size_action(fake_ipa_size:, expected_json:, **other_action_args)
@@ -31,9 +17,6 @@ def test_app_size_action(fake_ipa_size:, expected_json:, **other_action_args)
       ipa_path = File.join(tmp_dir, 'fake.ipa')
       File.write(ipa_path, SecureRandom.random_bytes(fake_ipa_size))
 
-      # Arrange: Mock GzipWriter with a mock for easier debugging in case of test failures
-      allow(Zlib::GzipWriter).to receive(:new).and_return(GzipWriterDouble.new)
-
       # Arrange: Stub any request to the mocked_endpoint, and memorize the received body
       expected_headers = {
         Authorization: "Bearer #{mocked_token}",
@@ -56,11 +39,14 @@ def test_app_size_action(fake_ipa_size:, expected_json:, **other_action_args)
       # Asserts
       expect(stub).to have_been_made.once
       expect(code).to eq(200)
-      expect(last_received_body).to start_with(GzipWriterDouble::GZIP_PREFIX), 'Payload is expected to be GZipped, but was not'
+      last_received_body_uncompressed = nil
+      expect do
+        last_received_body_uncompressed = Zlib.gunzip(last_received_body)
+      end.not_to raise_error, 'Payload was not valid GZipped data'
       # Compare the payloads as pretty-formatted JSON, to make the diff in test failures more readable if one happen
-      expect(pretty_json(last_received_body)).to eq(pretty_json(expected_json)), 'Decompressed JSON payload was not as expected'
-      # Compare the payloads as raw strings as a final check
-      expect(last_received_body).to eq(GzipWriterDouble.new(expected_json).string)
+      expect(pretty_json(last_received_body_uncompressed)).to eq(pretty_json(expected_json)), 'Decompressed JSON payload was not as expected'
+      # Compare the payloads as raw uncompressed data as a final check
+      expect(last_received_body_uncompressed).to eq(expected_json)
     end
   end