test: unknown case

src/test/java/io/github/algomaster99/bytecode/diff/visitor/ClassFileVisitorTest.java

@@ -12,6 +12,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
@@ -209,6 +210,47 @@ void shouldShowNoDifferenceInBytecode() throws IOException {
                 assertThat(rootOperations).size().isEqualTo(0);
             }
         }
+
+        @Nested
+        class DiffComp {
+            @Disabled(
+                    "This test is disabled because I have to check why gumtree gives so many changes even though the bytecode should be equivalent.")
+            @Test
+            void shouldShowNoDifferenceInBytecode_1() throws IOException {
+                // arrange
+                Path oldClass = EQ.resolve("DiffComp")
+                        .resolve("82141")
+                        .resolve("openjdk-17.0.1")
+                        .resolve("TapeInputStream.class");
+                Path newClass = EQ.resolve("DiffComp")
+                        .resolve("82141")
+                        .resolve("ecj-3.28.0_openjdk-11.0.19")
+                        .resolve("TapeInputStream.class");
+                DiffImpl diff = getDiff(oldClass, newClass);
+
+                // assert
+                List<Action> rootOperations = diff.getRootOperations();
+                assertThat(rootOperations).size().isEqualTo(1);
+            }
+
+            @Disabled("Unclear why there is a difference.")
+            @Test
+            void shouldShowNoDifferenceInBytecode_2() throws IOException {
+                Path oldClass = EQ.resolve("DiffComp")
+                        .resolve("82138")
+                        .resolve("openjdk-17.0.1")
+                        .resolve("DumpArchiveUtil.class");
+                Path newClass = EQ.resolve("DiffComp")
+                        .resolve("82138")
+                        .resolve("ecj-3.28.0_openjdk-11.0.19")
+                        .resolve("DumpArchiveUtil.class");
+                DiffImpl diff = getDiff(oldClass, newClass);
+
+                // assert
+                List<Action> rootOperations = diff.getRootOperations();
+                assertThat(rootOperations).size().isEqualTo(1);
+            }
+        }
     }
 
     private static DiffImpl getDiff(Path oldClass, Path newClass) throws IOException {

src/test/resources/EQ/DiffComp/82138/README.md

@@ -0,0 +1,2 @@
+Unclear what is happening.
+Both diff are bad for a known equivalent bytecode.

src/test/resources/EQ/DiffComp/82138/gumtree.diff

@@ -0,0 +1,27 @@
+[===
+insert-node
+---
+IRETURN [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 18, ===
+move-tree
+---
+ILOAD_2: IntType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 11, ===
+move-tree
+---
+SIPUSH [0,0]
+    ShortType: 256 [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 11, ===
+move-tree
+---
+ICONST_0 [0,0]
+    IntType: 0 [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 17]

src/test/resources/EQ/DiffComp/82141/README.md

@@ -0,0 +1,2 @@
+Unclear what is happening here.
+Diffoscope shows some spurious diff but gumtree is also failing in this case.

src/test/resources/EQ/DiffComp/82141/diffoscope.diff

@@ -0,0 +1,45 @@
+--- openjdk-17.0.1/TapeInputStream.class
++++ ecj-3.28.0_openjdk-11.0.19/TapeInputStream.class
+├── procyon -ec {}
+│ @@ -123,36 +123,37 @@
+│                  int length = h >> 4 & 0xFFFFFFF;
+│                  final byte[] compBuffer = this.readRange(length);
+│                  this.bytesRead += length;
+│                  if (!decompress) {
+│                      Arrays.fill(this.blockBuffer, (byte)0);
+│                  }
+│                  else {
+│ -                    switch (TapeInputStream.TapeInputStream$1.$SwitchMap$org$apache$commons$compress$archivers$dump$DumpArchiveConstants$COMPRESSION_TYPE[DumpArchiveConstants.COMPRESSION_TYPE.find(flags & 0x3).ordinal()]) {
+│ -                        case 1: {
+│ +                    switch (DumpArchiveConstants.COMPRESSION_TYPE.find(flags & 0x3)) {
+│ +                        case ZLIB: {
+│                              final Inflater inflator = new Inflater();
+│                              try {
+│                                  inflator.setInput(compBuffer, 0, compBuffer.length);
+│                                  length = inflator.inflate(this.blockBuffer);
+│                                  if (length != this.blockSize) {
+│                                      throw new ShortFileException();
+│                                  }
+│                              }
+│                              catch (final DataFormatException e) {
+│                                  throw new DumpArchiveException("Bad data", (Throwable)e);
+│                              }
+│                              finally {
+│                                  inflator.end();
+│                              }
+│ +                            inflator.end();
+│                              break;
+│                          }
+│ -                        case 2: {
+│ +                        case BZLIB: {
+│                              throw new UnsupportedCompressionAlgorithmException("BZLIB2");
+│                          }
+│ -                        case 3: {
+│ +                        case LZO: {
+│                              throw new UnsupportedCompressionAlgorithmException("LZO");
+│                          }
+│                          default: {
+│                              throw new UnsupportedCompressionAlgorithmException();
+│                          }
+│                      }
+│                  }

src/test/resources/EQ/DiffComp/82141/gumtree.diff

@@ -0,0 +1,88 @@
+[===
+update-node
+---
+METHOD_INVOKED_RETURN_TYPE: ()V [0,0]
+replace ()V by (Ljava/lang/String;)V, ===
+delete-node
+---
+GETSTATIC [0,0]
+===, ===
+delete-node
+---
+INVOKEVIRTUAL [0,0]
+===, ===
+insert-node
+---
+java.lang.classfile.FieldModel [0,0]
+to
+root [0,5945]
+at 9, ===
+insert-node
+---
+java.lang.classfile.MethodModel [0,0]
+to
+root [0,5945]
+at 23, ===
+insert-node
+---
+INVOKESTATIC [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 82, ===
+move-tree
+---
+ILOAD_3: IntType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 58, ===
+move-tree
+---
+ILOAD: IntType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 58, ===
+move-tree
+---
+INVOKEVIRTUAL [0,0]
+    METHOD_OWNER: java/util/zip/Inflater [0,0]
+    METHOD_INVOKED_NAME: end [0,0]
+    METHOD_INVOKED_RETURN_TYPE: ()V [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 116, ===
+move-tree
+---
+ALOAD: ReferenceType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 118, ===
+move-tree
+---
+INVOKEVIRTUAL [0,0]
+    METHOD_OWNER: java/util/zip/Inflater [0,0]
+    METHOD_INVOKED_NAME: end [0,0]
+    METHOD_INVOKED_RETURN_TYPE: ()V [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 118, ===
+move-tree
+---
+INVOKESPECIAL [0,0]
+    METHOD_OWNER: java/lang/StringBuilder [0,0]
+    METHOD_INVOKED_NAME: <init> [0,0]
+    METHOD_INVOKED_RETURN_TYPE: ()V [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 10, ===
+move-tree
+---
+LLOAD_1: LongType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 51, ===
+move-tree
+---
+LLOAD_3: LongType [0,0]
+to
+java.lang.classfile.CodeModel: CodeModel [0,0]
+at 51]