Only log failed comparisons

Author: waltflanagan

Tests/XcodeProjTests/Tests/testWrite.swift

@@ -12,7 +12,7 @@ func testWrite<T: Writable & Equatable>(file _: StaticString = #file,
     testWrite(from: path, initModel: initModel, modify: modify, assertion: { XCTAssertEqual($0, $1) })
 }
 
-func testWrite<T: Writable>(file: StaticString = #file,
+func testWrite<T: Writable & Equatable>(file: StaticString = #file,
                             line: UInt = #line,
                             from path: Path,
                             initModel: (Path) -> T?,
@@ -32,7 +32,9 @@ func testWrite<T: Writable>(file: StaticString = #file,
             XCTAssertNotNil(gotAfterWriting, file: file, line: line)
             if let gotAfterWriting {
                 assertion(got, gotAfterWriting)
-                print("-------\n(\(got)\n\n\n ------- \n\(gotAfterWriting)")
+                if got != gotAfterWriting {
+                    print("-------\n(\(got)\n\n\n ------- \n\(gotAfterWriting)")
+                }
             }
         } catch {
             XCTFail("It shouldn't throw an error writing the project: \(error.localizedDescription)", file: file, line: line)