Added unit tests for ios_get_build_number

Author: spencertransier

spec/ios_get_build_number_spec.rb

@@ -0,0 +1,66 @@
+require 'spec_helper'
+
+describe Fastlane::Actions::IosGetBuildNumberAction do
+  describe 'getting the build number from the provided .xcconfig file' do
+    it 'parses an xcconfig file with keys without spacing and returns the correct build number' do
+      xcconfig_mock_content = <<~CONTENT
+        // a comment
+        VERSION_SHORT=6
+        VERSION_LONG=6.30.0
+        BUILD_NUMBER=1940
+      CONTENT
+
+      expect_build_number(xcconfig_mock_content: xcconfig_mock_content, expected_build_number: '1940')
+    end
+
+    it 'parses an xcconfig file with keys with spaces and returns a nil build number' do
+      xcconfig_mock_content = <<~CONTENT
+        VERSION_SHORT = 6
+        VERSION_LONG = 6.30.1
+        BUILD_NUMBER = 1940
+      CONTENT
+
+      expect_build_number(xcconfig_mock_content: xcconfig_mock_content, expected_build_number: nil)
+    end
+
+    it 'parses an xcconfig file with an invalid format and returns a nil build number' do
+      xcconfig_mock_content = <<~CONTENT
+        VERSION_SHORT = 6
+        VERSION_LONG = 6.30.1
+        BUILD_NUMBER 1940
+      CONTENT
+
+      expect_build_number(xcconfig_mock_content: xcconfig_mock_content, expected_build_number: nil)
+    end
+
+    it 'parses an xcconfig file with no build number and returns a nil build number' do
+      xcconfig_mock_content = <<~CONTENT
+        VERSION_SHORT = 6
+        // a comment
+      CONTENT
+
+      expect_build_number(xcconfig_mock_content: xcconfig_mock_content, expected_build_number: nil)
+    end
+
+    it 'throws an error when the xcconfig file does not exist' do
+      file_path = 'file/not/found'
+
+      expect do
+        run_described_fastlane_action(
+          xcconfig_file_path: file_path
+        )
+      # Ruby error for 'No such file or directory': https://ruby-doc.org/core-2.7.4/SystemCallError.html
+      end.to raise_error(Errno::ENOENT)
+    end
+
+    def expect_build_number(xcconfig_mock_content:, expected_build_number:)
+      with_tmp_file(named: 'mock_xcconfig.xcconfig', content: xcconfig_mock_content) do |tmp_file_path|
+        build_number_result = run_described_fastlane_action(
+          xcconfig_file_path: tmp_file_path
+        )
+
+        expect(build_number_result).to eq(expected_build_number)
+      end
+    end
+  end
+end