[feat] Make Spork comply with git merge-file, fix #113

Some conflicts are currently compounded. For example, multiple conflicts in a comment counts as one conflict. But it is accurate for the most part.

src/main/java/se/kth/spork/cli/Cli.java

@@ -136,9 +136,9 @@ public Integer call() throws IOException {
                 rightPath.toFile().deleteOnExit();
             }
 
-            Pair<String, Boolean> merged = merge(basePath, leftPath, rightPath);
+            Pair<String, Integer> merged = merge(basePath, leftPath, rightPath);
             String pretty = merged.first;
-            boolean hasConflicts = merged.second;
+            int numConflicts = merged.second;
 
             if (out != null) {
                 LOGGER.info(() -> "Writing merge to " + out);
@@ -149,7 +149,7 @@ public Integer call() throws IOException {
             }
 
             LOGGER.info(() -> "Total time elapsed: " + (double) (System.nanoTime() - start) / 1e9 + " seconds");
-            return hasConflicts ? 1 : 0;
+            return numConflicts % 127;
         }
 
     }
@@ -160,22 +160,22 @@ public Integer call() throws IOException {
      * @param base Path to base revision.
      * @param left Path to left revision.
      * @param right Path to right revision.
-     * @return A pair on the form (prettyPrint, hasConflicts)
+     * @return A pair on the form (prettyPrint, numConflicts)
      */
-    public static Pair<String, Boolean> merge(Path base, Path left, Path right) {
+    public static Pair<String, Integer> merge(Path base, Path left, Path right) {
         LOGGER.info(() -> "Parsing input files");
         CtModule baseModule = Parser.parse(base);
         CtModule leftModule = Parser.parse(left);
         CtModule rightModule = Parser.parse(right);
 
         LOGGER.info(() -> "Initiating merge");
-        Pair<CtElement, Boolean> merge = Spoon3dmMerge.merge(baseModule, leftModule, rightModule);
+        Pair<CtElement, Integer> merge = Spoon3dmMerge.merge(baseModule, leftModule, rightModule);
         CtModule mergeTree = (CtModule) merge.first;
-        boolean hasConflicts = merge.second;
+        int numConflicts = merge.second;
 
         LOGGER.info(() -> "Pretty-printing");
         if (containsTypes(mergeTree)) {
-            return Pair.of(prettyPrint(mergeTree), hasConflicts);
+            return Pair.of(prettyPrint(mergeTree), numConflicts);
         } else {
             LOGGER.warn(() -> "Merge contains no types (i.e. classes, interfaces, etc), reverting to line-based merge");
             String baseStr = Parser.read(base);

src/main/java/se/kth/spork/spoon/Spoon3dmMerge.java

@@ -32,9 +32,9 @@ public class Spoon3dmMerge {
      * @param base  The base revision.
      * @param left  The left revision.
      * @param right The right revision.
-     * @return A pair on the form (mergeTree, hasConflicts).
+     * @return A pair on the form (mergeTree, numConflicts).
      */
-    public static Pair<CtModule, Boolean> merge(Path base, Path left, Path right) {
+    public static Pair<CtModule, Integer> merge(Path base, Path left, Path right) {
         long start = System.nanoTime();
 
         // PARSING PHASE
@@ -57,9 +57,9 @@ public static Pair<CtModule, Boolean> merge(Path base, Path left, Path right) {
      * @param base  The base revision.
      * @param left  The left revision.
      * @param right The right revision.
-     * @return A pair on the form (mergeTree, hasConflicts).
+     * @return A pair on the form (mergeTree, numConflicts).
      */
-    public static <T extends CtElement> Pair<T, Boolean> merge(T base, T left, T right) {
+    public static <T extends CtElement> Pair<T, Integer> merge(T base, T left, T right) {
         long start = System.nanoTime();
 
         // MATCHING PHASE
@@ -114,19 +114,20 @@ public static <T extends CtElement> Pair<T, Boolean> merge(T base, T left, T rig
 
         // INTERPRETER PHASE
         LOGGER.info(() -> "Interpreting resolved PCS merge");
-        Pair<CtElement, Boolean> merge = PcsInterpreter.fromMergedPcs(delta, baseLeft, baseRight);
+        Pair<CtElement, Integer> merge = PcsInterpreter.fromMergedPcs(delta, baseLeft, baseRight);
         // we can be certain that the merge tree has the same root type as the three constituents, so this cast is safe
         @SuppressWarnings("unchecked")
         T mergeTree = (T) merge.first;
-        boolean hasConflicts = merge.second;
+        int numConflicts = merge.second;
+
 
         LOGGER.info(() -> "Merging import statements");
         List<CtImport> mergedImports = mergeImportStatements(base, left, right);
         mergeTree.putMetadata(Parser.IMPORT_STATEMENTS, mergedImports);
 
         LOGGER.info(() -> "Merged in " + (double) (System.nanoTime() - start) / 1e9 + " seconds");
 
-        return Pair.of(mergeTree, hasConflicts);
+        return Pair.of(mergeTree, numConflicts);
     }
 
     /**

src/main/java/se/kth/spork/spoon/pcsinterpreter/ContentMerger.java

@@ -215,9 +215,9 @@ private static Optional<?> mergeIsUpper(Optional<CtElement> baseElem, CtElement
     }
 
     private static Optional<?> mergeComments(Object base, Object left, Object right) {
-        Pair<String, Boolean> merge = LineBasedMerge.merge(base.toString(), left.toString(), right.toString());
+        Pair<String, Integer> merge = LineBasedMerge.merge(base.toString(), left.toString(), right.toString());
 
-        if (merge.second) {
+        if (merge.second > 0) {
             return Optional.empty();
         }
         return Optional.of(merge.first);

src/main/java/se/kth/spork/spoon/pcsinterpreter/PcsInterpreter.java

@@ -20,9 +20,9 @@ public class PcsInterpreter {
      *
      * @param baseLeft  A tree matching between the base revision and the left revision.
      * @param baseRight A tree matching between the base revision and the right revision.
-     * @return A pair on the form (tree, hasStructuralConflicts).
+     * @return A pair on the form (tree, numConflicts).
      */
-    public static Pair<CtElement, Boolean> fromMergedPcs(
+    public static Pair<CtElement, Integer> fromMergedPcs(
             ChangeSet<SpoonNode, RoledValues> delta,
             SpoonMapping baseLeft,
             SpoonMapping baseRight) {
@@ -36,6 +36,6 @@ public static Pair<CtElement, Boolean> fromMergedPcs(
         SpoonTreeBuilder spoonTreeBuilder = new SpoonTreeBuilder(baseLeft, baseRight, oldEnv);
         CtElement spoonTreeRoot = spoonTreeBuilder.build(sporkTreeRoot);
 
-        return Pair.of(spoonTreeRoot, sporkTreeBuilder.hasStructuralConflict() || spoonTreeBuilder.hasContentConflict());
+        return Pair.of(spoonTreeRoot, sporkTreeBuilder.numStructuralConflicts() + spoonTreeBuilder.numContentConflicts());
     }
 }

src/main/java/se/kth/spork/spoon/pcsinterpreter/SpoonTreeBuilder.java

@@ -39,7 +39,7 @@ public class SpoonTreeBuilder {
 
     private SpoonMapping baseLeft;
     private SpoonMapping baseRight;
-    private boolean hasContentConflict = false;
+    private int numContentConflicts = 0;
 
     private Factory factory;
 
@@ -129,10 +129,10 @@ public CtElement build(SporkTree root) {
     }
 
     /**
-     * @return true if a content conflict was encountered when building the tree.
+     * @return The amount of content conflicts.
      */
-    public boolean hasContentConflict() {
-        return hasContentConflict;
+    public int numContentConflicts() {
+        return numContentConflicts;
     }
 
     /**
@@ -161,7 +161,7 @@ private CtElement visit(SporkTree sporkParent, SporkTree sporkChild) {
             if (!mergedContent.second.isEmpty()) {
                 // at least one conflict was not resolved
                 mergeTree.putMetadata(ContentConflict.METADATA_KEY, mergedContent.second);
-                hasContentConflict = true;
+                numContentConflicts += mergedContent.second.size();
             }
         }
 

src/main/java/se/kth/spork/spoon/pcsinterpreter/SporkTreeBuilder.java

@@ -21,7 +21,7 @@ class SporkTreeBuilder {
     private final Map<SpoonNode, Map<SpoonNode, Pcs<SpoonNode>>> rootToChildren;
     private final Map<Pcs<SpoonNode>, Set<Pcs<SpoonNode>>> structuralConflicts;
     private final Map<SpoonNode, Set<Content<SpoonNode, RoledValues>>> contents;
-    private boolean hasStructuralConflicts;
+    private int numStructuralConflicts;
 
     // keeps track of which nodes have been added to the tree all ready
     // if any node is added twice, there's an unresolved move conflict
@@ -36,7 +36,7 @@ public SporkTreeBuilder(ChangeSet<SpoonNode, RoledValues> delta) {
         this.rootToChildren = buildRootToChildren(delta.getPcsSet());
         structuralConflicts = delta.getStructuralConflicts();
         contents = delta.getContents();
-        hasStructuralConflicts = false;
+        numStructuralConflicts = 0;
         usedNodes = new HashSet<>();
     }
 
@@ -69,10 +69,10 @@ private static Optional<List<SpoonNode>> tryResolveConflict(List<SpoonNode> left
     }
 
     /**
-     * @return true iff conflicts were encountered at some point when building a tree.
+     * @return The amount of structural conflicts.
      */
-    public boolean hasStructuralConflict() {
-        return hasStructuralConflicts;
+    public int numStructuralConflicts() {
+        return numStructuralConflicts;
     }
 
     /**
@@ -137,7 +137,7 @@ private SpoonNode traverseConflict(
                     addChild(tree, build(child))
             );
         } else {
-            hasStructuralConflicts = true;
+            numStructuralConflicts++;
             StructuralConflict conflict = new StructuralConflict(
                     leftNodes.stream().map(SpoonNode::getElement).collect(Collectors.toList()),
                     rightNodes.stream().map(SpoonNode::getElement).collect(Collectors.toList())

src/main/java/se/kth/spork/spoon/printer/PrinterPreprocessor.java

@@ -137,8 +137,8 @@ private void processConflict(ContentConflict conflict, CtElement element) {
                 String rawBase = conflict.getBase().isPresent() ?
                         (String) conflict.getBase().get().getMetadata(RoledValue.Key.RAW_CONTENT) : "";
 
-                Pair<String, Boolean> rawConflict = LineBasedMerge.merge(rawBase, rawLeft, rawRight);
-                assert rawConflict.second : "Comments without conflict should already have been merged";
+                Pair<String, Integer> rawConflict = LineBasedMerge.merge(rawBase, rawLeft, rawRight);
+                assert rawConflict.second > 0 : "Comments without conflict should already have been merged";
 
                 element.putMetadata(RAW_COMMENT_CONFLICT_KEY, rawConflict.first);
                 break;

src/main/java/se/kth/spork/util/LineBasedMerge.java

@@ -26,13 +26,12 @@ public class LineBasedMerge {
      * @param base The base revision.
      * @param left The left revision.
      * @param right The right revision.
-     * @return A pair containing the merge and a boolean that, if true, indicates the presence of conflicts.
+     * @return A pair containing the merge and the amount of conflicts.
      */
-    public static Pair<String, Boolean> merge(String base, String left, String right) {
+    public static Pair<String, Integer> merge(String base, String left, String right) {
         RawText baseRaw = new RawText(base.getBytes());
         RawText leftRaw = new RawText(left.getBytes());
         RawText rightRaw = new RawText(right.getBytes());
-        boolean hasConflict = false;
 
         MergeAlgorithm merge = new MergeAlgorithm();
         MergeResult<RawText> res = merge.merge(new SequenceComparator<RawText>() {
@@ -51,13 +50,14 @@ public int hash(RawText s, int i) {
         List<RawText> seqs = res.getSequences();
         List<String> lines = new ArrayList<>();
         boolean inConflict = false;
+        int numConflicts = 0;
 
         while (it.hasNext()) {
             MergeChunk chunk = it.next();
             RawText seq = seqs.get(chunk.getSequenceIndex());
 
             if (chunk.getConflictState() == MergeChunk.ConflictState.FIRST_CONFLICTING_RANGE) {
-                hasConflict = true;
+                numConflicts++;
                 inConflict = true;
                 lines.add(SporkPrettyPrinter.START_CONFLICT);
             } else if (chunk.getConflictState() == MergeChunk.ConflictState.NEXT_CONFLICTING_RANGE) {
@@ -86,6 +86,6 @@ public int hash(RawText s, int i) {
             lines.add(SporkPrettyPrinter.END_CONFLICT);
         }
 
-        return new Pair<>(String.join("\n", lines), hasConflict);
+        return new Pair<>(String.join("\n", lines), numConflicts);
     }
 }

src/test/java/se/kth/spork/cli/CliTest.java

@@ -66,9 +66,9 @@ void mergeTreeShouldEqualReParsedPrettyPrent_whenBothRevisionsAreModified(Util.T
     void prettyPrint_shouldContainConflict(Util.TestSources sources) throws IOException {
         List<Util.Conflict> expectedConflicts = Util.parseConflicts(sources.expected);
 
-        Pair<CtModule, Boolean> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
+        Pair<CtModule, Integer> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
         CtModule mergeTree = merged.first;
-        boolean hasConflicts = merged.second;
+        Integer numConflicts = merged.second;
 
         String prettyPrint = Cli.prettyPrint(mergeTree);
 
@@ -77,15 +77,15 @@ void prettyPrint_shouldContainConflict(Util.TestSources sources) throws IOExcept
         System.out.println(prettyPrint);
 
         assertEquals(expectedConflicts, actualConflicts);
-        assertTrue(hasConflicts);
+        assertTrue(numConflicts > 0);
     }
 
     @ParameterizedTest
     @ArgumentsSource(Util.ConflictSourceProvider.class)
     void prettyPrint_shouldParseToExpectedTree_whenConflictHasBeenStrippedOut(Util.TestSources sources) throws IOException {
         CtModule expected = Parser.parse(Util.keepLeftConflict(sources.expected));
 
-        Pair<CtModule, Boolean> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
+        Pair<CtModule, Integer> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
         CtModule mergeTree = merged.first;
 
         String prettyPrint = Cli.prettyPrint(mergeTree);
@@ -102,7 +102,7 @@ void prettyPrint_shouldParseToExpectedTree_whenConflictHasBeenStrippedOut(Util.T
      * @param sources
      */
     private static void runTestMerge(Util.TestSources sources, Path tempDir) throws IOException {
-        Pair<CtModule, Boolean> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
+        Pair<CtModule, Integer> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
         CtModule mergeTree = merged.first;
 
         Object expectedImports = mergeTree.getMetadata(Parser.IMPORT_STATEMENTS);

src/test/java/se/kth/spork/spoon/Spoon3dmMergeTest.java

@@ -36,7 +36,7 @@ private static void runTestMerge(Util.TestSources sources) {
         Object expectedImports = expected.getMetadata(Parser.IMPORT_STATEMENTS);
         assert expectedImports != null;
 
-        Pair<CtModule, Boolean> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
+        Pair<CtModule, Integer> merged = Spoon3dmMerge.merge(sources.base, sources.left, sources.right);
         CtModule mergeTree = merged.first;
         Object mergedImports = mergeTree.getMetadata(Parser.IMPORT_STATEMENTS);