Fix TemporaryFolderToTempDir: Don't add methods to unrelated classes

[amishra-u]

What's changed?

The TemporaryFolderToTempDir recipe was previously adding newFolder and newFile methods to all classes in the compilation unit and this may produce uncompilable code. The updated code now adds these methods only to the relevant class.

Before

class MyTest {
      @Rule
      TemporaryFolder tempDir1 = new TemporaryFolder();
      void foo() throws IOException {
          File file1 = tempDir1.newFolder();
      }
      class InnerClass {
         private static File newFolder(File root, String... subDirs) throws IOException {}
      }
      
      private static File newFolder(File root, String... subDirs) throws IOException { }
  }

After

class MyTest {
      @Rule
      TemporaryFolder tempDir1 = new TemporaryFolder();
      void foo() throws IOException {
          File file1 = tempDir1.newFolder();
      }
      class InnerClass { }
      
      private static File newFolder(File root, String... subDirs) throws IOException { }
  }

Anyone you would like to review specifically?

@timtebeek

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[github-actions]

Some suggestions could not be made:

• src/main/resources/META-INF/rewrite/examples.yml
  • lines 2583-2598
  • lines 3392-3391
  • lines 3427-3445

[timtebeek]

Yes makes sense, thanks!