[Installer] Add specs for deintegrating on major version changes

lib/cocoapods/installer.rb

@@ -494,8 +494,8 @@ module Pod
     # @return [void]
     #
     def deintegrate_if_different_major_version
-      return unless config.lockfile
-      return if config.lockfile.cocoapods_version.major == Version.new(VERSION).major
+      return unless lockfile
+      return if lockfile.cocoapods_version.major == Version.create(VERSION).major
       UI.section('Fully deintegrating due to major version update') do
         projects = Pathname.glob(config.installation_root + '*.xcodeproj').map { |path| Xcodeproj::Project.open(path) }
         deintegrator = Deintegrator.new

spec/unit/installer_spec.rb

@@ -4,12 +4,12 @@ require 'cocoapods_stats/sender'
 
 # @return [Lockfile]
 #
-def generate_lockfile
+def generate_lockfile(lockfile_version: Pod::VERSION)
   hash = {}
   hash['PODS'] = []
   hash['DEPENDENCIES'] = []
   hash['SPEC CHECKSUMS'] = []
-  hash['COCOAPODS'] = Pod::VERSION
+  hash['COCOAPODS'] = lockfile_version
   Pod::Lockfile.new(hash)
 end
 
@@ -177,6 +177,38 @@ module Pod
           end.message.should.match /should.*run.*outside.*Pods directory.*Current directory.*\./m
         end
       end
+
+      describe 'handling CocoaPods version updates' do
+        it 'does not deintegrate when there is no lockfile' do
+          installer = Pod::Installer.new(config.sandbox, generate_podfile, nil)
+          UI.expects(:section).never
+          installer.send(:deintegrate_if_different_major_version)
+        end
+
+        it 'does not deintegrate when the major version is the same' do
+          VERSION.stubs(:to_s).returns('1.1.0')
+          should_not_deintegrate = %w(1.0.0 1.0.1 1.1.0 1.2.2)
+          should_not_deintegrate.each do |version|
+            lockfile = generate_lockfile(:lockfile_version => version)
+            installer = Pod::Installer.new(config.sandbox, generate_podfile, lockfile)
+            Pathname.expects(:glob).never
+            installer.send(:deintegrate_if_different_major_version)
+          end
+        end
+
+        it 'does deintegrate when the major version is the same' do
+          VERSION.stubs(:to_s).returns('1.1.0')
+          should_not_deintegrate = %w(0.39.0 2.0.0 10.0-beta)
+          should_not_deintegrate.each do |version|
+            lockfile = generate_lockfile(:lockfile_version => version)
+            installer = Pod::Installer.new(config.sandbox, generate_podfile, lockfile)
+            project = fixture('SampleProject/SampleProject.xcodeproj')
+            Pathname.expects(:glob).with(config.installation_root + '*.xcodeproj').returns([project])
+            Deintegrator.any_instance.expects(:deintegrate_project)
+            installer.send(:deintegrate_if_different_major_version)
+          end
+        end
+      end
     end
 
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