Add Dart code to diff_view

tests/compiler/dart2js/sourcemaps/diff.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library sourcemap.diff;
+
+import 'package:compiler/src/io/source_file.dart';
+
+import 'html_parts.dart';
+import 'output_structure.dart';
+import 'sourcemap_helper.dart';
+
+enum DiffKind {
+  UNMATCHED,
+  MATCHING,
+  IDENTICAL,
+}
+
+/// A list of columns that should align in output.
+class DiffBlock {
+  final DiffKind kind;
+  List<List<HtmlPart>> columns = <List<HtmlPart>>[];
+
+  DiffBlock(this.kind);
+
+  void addColumn(int index, List<HtmlPart> lines) {
+    if (index >= columns.length) {
+      columns.length = index + 1;
+    }
+    columns[index] = lines;
+  }
+
+  List<HtmlPart> getColumn(int index) {
+    List<HtmlPart> lines;
+    if (index < columns.length) {
+      lines = columns[index];
+    }
+    return lines != null ? lines : const <HtmlPart>[];
+  }
+}
+
+
+/// Align the content of [list1] and [list2].
+///
+/// If provided, [range1] and [range2] aligned the subranges of [list1] and
+/// [list2], otherwise the whole lists are aligned.
+///
+/// If provided, [match] determines the equality between members of [list1] and
+/// [list2], otherwise `==` is used.
+///
+/// [handleSkew] is called when a subrange of one list is not found in the
+/// other.
+///
+/// [handleMatched] is called when two indices match up.
+///
+/// [handleUnmatched] is called when two indices don't match up (none are found
+/// in the other list).
+void align(List list1,
+           List list2,
+           {Interval range1,
+            Interval range2,
+            bool match(a, b),
+            void handleSkew(int listIndex, Interval range),
+            void handleMatched(List<int> indices),
+            void handleUnmatched(List<int> indices)}) {
+  if (match == null) {
+    match = (a, b) => a == b;
+  }
+
+  if (range1 == null) {
+    range1 = new Interval(0, list1.length);
+  }
+  if (range2 == null) {
+    range2 = new Interval(0, list2.length);
+  }
+
+  Interval findInOther(
+      List thisLines, Interval thisRange,
+      List otherLines, Interval otherRange) {
+    for (int index = otherRange.from; index < otherRange.to; index++) {
+      if (match(thisLines[thisRange.from], otherLines[index])) {
+        int offset = 1;
+        while (thisRange.from + offset < thisRange.to &&
+               otherRange.from + offset < otherRange.to &&
+               match(thisLines[thisRange.from + offset],
+                     otherLines[otherRange.from + offset])) {
+          offset++;
+        }
+        return new Interval(index, index + offset);
+      }
+    }
+    return null;
+  }
+
+  int start1 = range1.from;
+  int end1 = range1.to;
+  int start2 = range2.from;
+  int end2 = range2.to;
+
+  const int ALIGN1 = -1;
+  const int UNMATCHED = 0;
+  const int ALIGN2 = 1;
+
+  while (start1 < end1 && start2 < end2) {
+    if (match(list1[start1], list2[start2])) {
+      handleMatched([start1++, start2++]);
+    } else {
+      Interval subrange1 = new Interval(start1, end1);
+      Interval subrange2 = new Interval(start2, end2);
+      Interval element2inList1 =
+          findInOther(list1, subrange1, list2, subrange2);
+      Interval element1inList2 =
+          findInOther(list2, subrange2, list1, subrange1);
+      int choice = 0;
+      if (element2inList1 != null) {
+        if (element1inList2 != null) {
+          if (element1inList2.length > 1 && element2inList1.length > 1) {
+            choice =
+                element2inList1.from < element1inList2.from ? ALIGN2 : ALIGN1;
+          } else if (element2inList1.length > 1) {
+            choice = ALIGN2;
+          } else if (element1inList2.length > 1) {
+            choice = ALIGN1;
+          } else {
+            choice =
+                element2inList1.from < element1inList2.from ? ALIGN2 : ALIGN1;
+          }
+        } else {
+          choice = ALIGN2;
+        }
+      } else if (element1inList2 != null) {
+        choice = ALIGN1;
+      }
+      switch (choice) {
+        case ALIGN1:
+          handleSkew(0, new Interval(start1, element1inList2.from));
+          start1 = element1inList2.from;
+          break;
+        case ALIGN2:
+          handleSkew(1, new Interval(start2, element2inList1.from));
+          start2 = element2inList1.from;
+          break;
+        case UNMATCHED:
+          handleUnmatched([start1++, start2++]);
+          break;
+      }
+    }
+  }
+  if (start1 < end1) {
+    handleSkew(0, new Interval(start1, end1));
+  }
+  if (start2 < end2) {
+    handleSkew(1, new Interval(start2, end2));
+  }
+}
+
+/// Create a list of blocks containing the diff of the two output [structures]
+/// and the corresponding Dart code.
+List<DiffBlock> createDiffBlocks(
+    List<OutputStructure> structures,
+    SourceFileManager sourceFileManager) {
+  return new DiffCreator(structures, sourceFileManager).computeBlocks();
+}
+
+class DiffCreator {
+  final List<OutputStructure> structures;
+  final SourceFileManager sourceFileManager;
+
+  List<List<CodeLine>> inputLines;
+
+  List<int> nextInputLine = [0, 0];
+
+  List<DiffBlock> blocks = <DiffBlock>[];
+
+  DiffCreator(List<OutputStructure> structures, this.sourceFileManager)
+      : this.structures = structures,
+        this.inputLines = structures.map((s) => s.lines).toList();
+
+  CodeSource codeSourceFromEntities(Iterable<OutputEntity> entities) {
+    for (OutputEntity entity in entities) {
+      if (entity.codeSource != null) {
+        return entity.codeSource;
+      }
+    }
+    return null;
+  }
+
+  /// Checks that lines are added in sequence without gaps or duplicates.
+  void checkLineInvariant(int index, Interval range) {
+    int expectedLineNo = nextInputLine[index];
+    if (range.from != expectedLineNo) {
+      print('Expected line no $expectedLineNo, found ${range.from}');
+      if (range.from < expectedLineNo) {
+        print('Duplicate lines:');
+        int i = range.from;
+        while (i <= expectedLineNo) {
+          print(inputLines[index][i++].code);
+        }
+      } else {
+        print('Missing lines:');
+        int i = expectedLineNo;
+        while (i <= range.from) {
+          print(inputLines[index][i++].code);
+        }
+      }
+    }
+    nextInputLine[index] = range.to;
+  }
+
+  /// Creates a block containing the code lines in [range] from input number
+  /// [index]. If [codeSource] is provided, the block will contain a
+  /// corresponding Dart code column.
+  void handleSkew(int index, Interval range, [CodeSource codeSource]) {
+    DiffBlock block = new DiffBlock(DiffKind.UNMATCHED);
+    checkLineInvariant(index, range);
+    block.addColumn(index, inputLines[index].sublist(range.from, range.to));
+    if (codeSource != null) {
+      block.addColumn(2,
+          codeLinesFromCodeSource(sourceFileManager, codeSource));
+    }
+    blocks.add(block);
+  }
+
+  /// Create a block containing the code lines in [ranges] from the
+  /// corresponding JavaScript inputs. If [codeSource] is provided, the block
+  /// will contain a corresponding Dart code column.
+  void addLines(DiffKind kind, List<Interval> ranges, [CodeSource codeSource]) {
+    DiffBlock block = new DiffBlock(kind);
+    for (int i = 0; i < ranges.length; i++) {
+      checkLineInvariant(i, ranges[i]);
+      block.addColumn(i, inputLines[i].sublist(ranges[i].from, ranges[i].to));
+    }
+    if (codeSource != null) {
+      block.addColumn(2,
+          codeLinesFromCodeSource(sourceFileManager, codeSource));
+    }
+    blocks.add(block);
+  }
+
+  /// Merge the code lines in [range1] and [range2] of the corresponding input.
+  void addRaw(Interval range1, Interval range2) {
+    match(a, b) => a.code == b.code;
+
+    List<Interval> currentMatchedIntervals;
+    List<Interval> currentUnmatchedIntervals;
+
+    void flushMatching() {
+      if (currentMatchedIntervals != null) {
+        addLines(DiffKind.IDENTICAL, currentMatchedIntervals);
+      }
+      currentMatchedIntervals = null;
+    }
+
+    void flushUnmatched() {
+      if (currentUnmatchedIntervals != null) {
+        addLines(DiffKind.UNMATCHED, currentUnmatchedIntervals);
+      }
+      currentUnmatchedIntervals = null;
+    }
+
+    List<Interval> updateIntervals(List<Interval> current, List<int> indices) {
+      if (current == null) {
+        return [
+          new Interval(indices[0], indices[0] + 1),
+          new Interval(indices[1], indices[1] + 1)];
+      } else {
+        current[0] =
+            new Interval(current[0].from, indices[0] + 1);
+        current[1] =
+            new Interval(current[1].from, indices[1] + 1);
+        return current;
+      }
+    }
+
+    align(
+        inputLines[0],
+        inputLines[1],
+        range1: range1,
+        range2: range2,
+        match: match,
+        handleSkew: (int listIndex, Interval range) {
+          flushMatching();
+          flushUnmatched();
+          handleSkew(listIndex, range);
+        },
+        handleMatched: (List<int> indices) {
+          flushUnmatched();
+          currentMatchedIntervals =
+              updateIntervals(currentMatchedIntervals, indices);
+        },
+        handleUnmatched: (List<int> indices) {
+          flushMatching();
+          currentUnmatchedIntervals =
+              updateIntervals(currentUnmatchedIntervals, indices);
+        });
+
+    flushMatching();
+    flushUnmatched();
+  }
+
+  /// Adds the top level blocks in [childRange] for structure [index].
+  void addBlock(int index, Interval childRange) {
+    addSkewedChildren(index, structures[index], childRange);
+  }
+
+  /// Adds the [entity] from structure [index]. If the [entity] supports child
+  /// entities, these are process individually. Otherwise the lines from
+  /// [entity] are added directly.
+  void addSkewedEntity(int index, OutputEntity entity) {
+    if (entity.canHaveChildren) {
+      handleSkew(index, entity.header);
+      addSkewedChildren(
+          index, entity, new Interval(0, entity.children.length));
+      handleSkew(index, entity.footer);
+    } else {
+      handleSkew(index, entity.interval, codeSourceFromEntities([entity]));
+    }
+  }
+
+  /// Adds the children of [parent] in [childRange] from structure [index].
+  void addSkewedChildren(int index, OutputEntity parent, Interval childRange) {
+    for (int i = childRange.from; i < childRange.to; i++) {
+      addSkewedEntity(index, parent.getChild(i));
+    }
+  }
+
+  /// Adds the members of the [classes] aligned.
+  void addMatchingContainers(List<OutputEntity> classes) {
+    addLines(DiffKind.MATCHING, classes.map((c) => c.header).toList());
+    align(classes[0].children, classes[1].children,
+        match: (a, b) => a.name == b.name,
+        handleSkew: (int listIndex, Interval childRange) {
+          addSkewedChildren(listIndex, classes[listIndex], childRange);
+        },
+        handleMatched: (List<int> indices) {
+          List<BasicEntity> entities =  [
+              classes[0].getChild(indices[0]),
+              classes[1].getChild(indices[1])];
+          if (entities.every((e) => e is Statics)) {
+            addMatchingContainers(entities);
+          } else {
+            addLines(DiffKind.MATCHING,
+                     entities.map((e) => e.interval).toList(),
+                     codeSourceFromEntities(entities));
+          }
+        },
+        handleUnmatched: (List<int> indices) {
+          List<Interval> intervals =  [
+              classes[0].getChild(indices[0]).interval,
+              classes[1].getChild(indices[1]).interval];
+          addLines(DiffKind.UNMATCHED, intervals);
+        });
+    addLines(DiffKind.MATCHING, classes.map((c) => c.footer).toList());
+  }
+
+  /// Adds the library blocks in [indices] from the corresponding
+  /// [OutputStructure]s, aligning their content.
+  void addMatchingBlocks(List<int> indices) {
+    List<LibraryBlock> blocks = [
+      structures[0].getChild(indices[0]),
+      structures[1].getChild(indices[1])];
+
+    addLines(DiffKind.MATCHING, blocks.map((b) => b.header).toList());
+    align(blocks[0].children, blocks[1].children,
+        match: (a, b) => a.name == b.name,
+        handleSkew: (int listIndex, Interval childRange) {
+          addSkewedChildren(
+              listIndex, blocks[listIndex], childRange);
+        },
+        handleMatched: (List<int> indices) {
+          List<BasicEntity> entities =  [
+              blocks[0].getChild(indices[0]),
+              blocks[1].getChild(indices[1])];
+          if (entities.every((e) => e is LibraryClass)) {
+            addMatchingContainers(entities);
+          } else {
+            addLines(
+                DiffKind.MATCHING,
+                entities.map((e) => e.interval).toList(),
+                codeSourceFromEntities(entities));
+          }
+        },
+        handleUnmatched: (List<int> indices) {
+          List<Interval> intervals =  [
+              blocks[0].getChild(indices[0]).interval,
+              blocks[1].getChild(indices[1]).interval];
+          addLines(DiffKind.UNMATCHED, intervals);
+        });
+    addLines(DiffKind.MATCHING, blocks.map((b) => b.footer).toList());
+  }
+
+  /// Adds the lines of the blocks in [indices] from the corresponding
+  /// [OutputStructure]s.
+  void addUnmatchedBlocks(List<int> indices) {
+    List<LibraryBlock> blocks = [
+       structures[0].getChild(indices[0]),
+       structures[1].getChild(indices[1])];
+    addLines(DiffKind.UNMATCHED, [blocks[0].interval, blocks[1].interval]);
+  }
+
+  /// Computes the diff blocks for [OutputStructure]s.
+  List<DiffBlock> computeBlocks() {
+    addRaw(structures[0].header, structures[1].header);
+
+    align(structures[0].children,
+          structures[1].children,
+          match: (a, b) => a.name == b.name,
+          handleSkew: addBlock,
+          handleMatched: addMatchingBlocks,
+          handleUnmatched: addUnmatchedBlocks);
+
+    addRaw(structures[0].footer, structures[1].footer);
+
+    return blocks;
+  }
+}
+
+/// Creates html lines for code lines in [codeSource]. [sourceFileManager] is
+/// used to read that text from the source URIs.
+List<HtmlPart> codeLinesFromCodeSource(
+    SourceFileManager sourceFileManager,
+    CodeSource codeSource) {
+  List<HtmlPart> lines = <HtmlPart>[];
+  SourceFile sourceFile = sourceFileManager.getSourceFile(codeSource.uri);
+  String elementName = codeSource.name;
+  HtmlLine line = new HtmlLine();
+  line.htmlParts.add(new ConstHtmlPart('<span class="comment">'));
+  line.htmlParts.add(new HtmlText(
+      '${elementName}: ${sourceFile.filename}'));
+  line.htmlParts.add(new ConstHtmlPart('</span>'));
+  lines.add(line);
+  if (codeSource.begin != null) {
+    int startLine = sourceFile.getLine(codeSource.begin);
+    int endLine = sourceFile.getLine(codeSource.end);
+    for (int lineNo = startLine; lineNo <= endLine; lineNo++) {
+      String text = sourceFile.getLineText(lineNo);
+      CodeLine codeLine = new CodeLine(lineNo, sourceFile.getOffset(lineNo, 0));
+      codeLine.codeBuffer.write(text);
+      codeLine.htmlParts.add(new HtmlText(text));
+      lines.add(codeLine);
+    }
+  }
+  return lines;
+}