tests/compiler/dart2js/sourcemaps/sourcemap_html_helper.dart - sdk.git - Git at Google

 // Copyright (c) 2015, 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.

 /// Helper for creating HTML visualization of the source map information
 /// generated by a [SourceMapProcessor].

 library sourcemap.html.helper;

 import 'dart:convert';

 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/io/source_information.dart';
 import 'package:compiler/src/js/js.dart' as js;

 import 'colors.dart';
 import 'sourcemap_helper.dart';
 import 'sourcemap_html_templates.dart';

 /// Returns the [index]th color for visualization.
 HSV toColor(int index) {
   int hueCount = 24;
   double h = 360.0 * (index % hueCount) / hueCount;
   double v = 1.0;
   double s = 0.5;
   return new HSV(h, s, v);
 }

 /// Return the CSS color value for the [index]th color.
 String toColorCss(int index) {
   return toColor(index).toCss;
 }

 /// Return the CSS color value for the [index]th span.
 String toPattern(int index) {
   /// Use gradient on spans to visually identify consecutive spans mapped to the
   /// same source location.
   HSV startColor = toColor(index);
   HSV endColor = new HSV(startColor.h, startColor.s + 0.4, startColor.v - 0.2);
   return 'linear-gradient(to right, ${startColor.toCss}, ${endColor.toCss})';
 }

 /// Return the html for the [index] line number.
 String lineNumber(int index) {
   return '<span class="lineNumber">${index + 1} </span>';
 }

 /// Return the html escaped [text].
 String escape(String text) {
   return const HtmlEscape().convert(text);
 }

 /// Information needed to generate HTML for a single [SourceMapInfo].
 class SourceMapHtmlInfo {
   final SourceMapInfo sourceMapInfo;
   final CodeProcessor codeProcessor;
   final SourceLocationCollection sourceLocationCollection;

   SourceMapHtmlInfo(this.sourceMapInfo,
                     this.codeProcessor,
                     this.sourceLocationCollection);
 }

 /// A collection of source locations.
 ///
 /// Used to index source locations for visualization and linking.
 class SourceLocationCollection {
   List<SourceLocation> sourceLocations = [];
   Map<SourceLocation, int> sourceLocationIndexMap;

   SourceLocationCollection([SourceLocationCollection parent])
       : sourceLocationIndexMap =
             parent == null ? {} : parent.sourceLocationIndexMap;

   int registerSourceLocation(SourceLocation sourceLocation) {
     return sourceLocationIndexMap.putIfAbsent(sourceLocation, () {
       sourceLocations.add(sourceLocation);
       return sourceLocationIndexMap.length;
     });
   }

   int getIndex(SourceLocation sourceLocation) {
     return sourceLocationIndexMap[sourceLocation];
   }
 }

 /// Processor that computes the HTML representation of a block of JavaScript
 /// code and collects the source locations mapped in the code.
 class CodeProcessor {
   int lineIndex = 0;
   final String onclick;
   int currentJsSourceOffset = 0;
   final SourceLocationCollection collection;
   final Map<int, List<SourceLocation>> codeLocations = {};

   CodeProcessor(this.onclick, this.collection);

   void addSourceLocation(int targetOffset, SourceLocation sourceLocation) {
     codeLocations.putIfAbsent(targetOffset, () => []).add(sourceLocation);
     collection.registerSourceLocation(sourceLocation);
   }

   String convertToHtml(String text) {
     StringBuffer htmlBuffer = new StringBuffer();
     int offset = 0;
     int lineIndex = 0;
     bool pendingSourceLocationsEnd = false;
     htmlBuffer.write(lineNumber(lineIndex));
     SourceLocation currentLocation;

     void endCurrentLocation() {
       if (currentLocation != null) {
         htmlBuffer.write('</a>');
       }
       currentLocation = null;
     }

     void addSubstring(int until) {
       if (until <= offset) return;

       String substring = text.substring(offset, until);
       offset = until;
       bool first = true;
       for (String line in substring.split('\n')) {
         if (!first) {
           endCurrentLocation();
           htmlBuffer.write('\n');
           lineIndex++;
           htmlBuffer.write(lineNumber(lineIndex));
         }
         htmlBuffer.write(escape(line));
         first = false;
       }
     }

     void insertSourceLocations(List<SourceLocation> lastSourceLocations) {
       endCurrentLocation();

       String color;
       int index;
       String title;
       if (lastSourceLocations.length == 1) {
         SourceLocation sourceLocation = lastSourceLocations.single;
         if (sourceLocation != null) {
           index = collection.getIndex(sourceLocation);
           color = "background:${toPattern(index)};";
           title = sourceLocation.shortText;
           currentLocation = sourceLocation;
         }
       } else {

         index = collection.getIndex(lastSourceLocations.first);
         StringBuffer sb = new StringBuffer();
         double delta = 100.0 / (lastSourceLocations.length);
         double position = 0.0;

         void addColor(String color) {
           sb.write(', ${color} ${position.toInt()}%');
           position += delta;
           sb.write(', ${color} ${position.toInt()}%');
         }

         for (SourceLocation sourceLocation in lastSourceLocations) {
           if (sourceLocation == null) continue;
           int colorIndex = collection.getIndex(sourceLocation);
           addColor('${toColorCss(colorIndex)}');
           currentLocation = sourceLocation;
         }
         color = 'background: linear-gradient(to right${sb}); '
                 'background-size: 10px 10px;';
         title = lastSourceLocations.map((l) => l.shortText).join(',');
       }
       if (index != null) {
         Set<int> indices =
             lastSourceLocations.map((l) => collection.getIndex(l)).toSet();
         String onmouseover = indices.map((i) => '\'$i\'').join(',');
         htmlBuffer.write(
             '<a name="js$index" href="#${index}" style="$color" title="$title" '
             'onclick="${onclick}" onmouseover="highlight([${onmouseover}]);"'
             'onmouseout="highlight([]);">');
         pendingSourceLocationsEnd = true;
       }
       if (lastSourceLocations.last == null) {
         endCurrentLocation();
       }
     }

     for (int targetOffset in codeLocations.keys.toList()..sort()) {
       List<SourceLocation> sourceLocations = codeLocations[targetOffset];
       addSubstring(targetOffset);
       insertSourceLocations(sourceLocations);
     }

     addSubstring(text.length);
     endCurrentLocation();
     return htmlBuffer.toString();
   }
 }

 /// Computes the HTML representation for a collection of JavaScript code blocks.
 String computeJsHtml(Iterable<SourceMapHtmlInfo> infoList) {

   StringBuffer jsCodeBuffer = new StringBuffer();
   for (SourceMapHtmlInfo info in infoList) {
     String name = info.sourceMapInfo.name;
     String html = info.codeProcessor.convertToHtml(info.sourceMapInfo.code);
     String onclick = 'show(\'$name\');';
     jsCodeBuffer.write(
         '<h3 onclick="$onclick">JS code for: ${escape(name)}</h3>\n');
     jsCodeBuffer.write('''
 <pre>
 $html
 </pre>
 ''');
   }
   return jsCodeBuffer.toString();
 }

 /// Computes the HTML representation of the source mapping information for a
 /// collection of JavaScript code blocks.
 String computeJsTraceHtml(Iterable<SourceMapHtmlInfo> infoList) {
   StringBuffer jsTraceBuffer = new StringBuffer();
   for (SourceMapHtmlInfo info in infoList) {
     String name = info.sourceMapInfo.name;
     String jsTrace = computeJsTraceHtmlPart(
         info.sourceMapInfo.codePoints, info.sourceLocationCollection);
     jsTraceBuffer.write('''
 <div name="$name" class="js-trace-buffer" style="display:none;">
 <h3>Trace for: ${escape(name)}</h3>
 $jsTrace
 </div>
 ''');
   }
   return jsTraceBuffer.toString();
 }

 /// Computes the HTML information for the [info].
 SourceMapHtmlInfo createHtmlInfo(SourceLocationCollection collection,
                                  SourceMapInfo info) {
   js.Node node = info.node;
   String code = info.code;
   String name = info.name;
   String onclick = 'show(\'$name\');';
   SourceLocationCollection subcollection =
       new SourceLocationCollection(collection);
   CodeProcessor codeProcessor = new CodeProcessor(onclick, subcollection);
   for (js.Node node in info.nodeMap.nodes) {
     info.nodeMap[node].forEach(
         (int targetOffset, List<SourceLocation> sourceLocations) {
       for (SourceLocation sourceLocation in sourceLocations) {
         codeProcessor.addSourceLocation(targetOffset, sourceLocation);
       }
     });
   }
   return new SourceMapHtmlInfo(info, codeProcessor, subcollection);
 }

 /// Outputs a HTML file in [jsMapHtmlUri] containing an interactive
 /// visualization of the source mapping information in [infoList] computed
 /// with the [sourceMapProcessor].
 void createTraceSourceMapHtml(Uri jsMapHtmlUri,
                               SourceMapProcessor sourceMapProcessor,
                               Iterable<SourceMapInfo> infoList) {
   SourceFileManager sourceFileManager = sourceMapProcessor.sourceFileManager;
   SourceLocationCollection collection = new SourceLocationCollection();
   List<SourceMapHtmlInfo> htmlInfoList = <SourceMapHtmlInfo>[];
   for (SourceMapInfo info in infoList) {
     htmlInfoList.add(createHtmlInfo(collection, info));
   }

   String jsCode = computeJsHtml(htmlInfoList);
   String dartCode = computeDartHtml(sourceFileManager, htmlInfoList);

   String jsTraceHtml = computeJsTraceHtml(htmlInfoList);
   outputJsDartTrace(jsMapHtmlUri, jsCode, dartCode, jsTraceHtml);
   print('Trace source map html generated: $jsMapHtmlUri');
 }

 /// Computes the HTML representation for the Dart code snippets referenced in
 /// [infoList].
 String computeDartHtml(
     SourceFileManager sourceFileManager,
     Iterable<SourceMapHtmlInfo> infoList) {

   StringBuffer dartCodeBuffer = new StringBuffer();
   for (SourceMapHtmlInfo info in infoList) {
     dartCodeBuffer.write(computeDartHtmlPart(info.sourceMapInfo.name,
          sourceFileManager, info.sourceLocationCollection));
   }
   return dartCodeBuffer.toString();

 }

 /// Computes the HTML representation for the Dart code snippets in [collection].
 String computeDartHtmlPart(String name,
                            SourceFileManager sourceFileManager,
                            SourceLocationCollection collection,
                            {bool showAsBlock: false}) {
   const int windowSize = 3;
   StringBuffer dartCodeBuffer = new StringBuffer();
   Map<Uri, Map<int, List<SourceLocation>>> sourceLocationMap = {};
   collection.sourceLocations.forEach((SourceLocation sourceLocation) {
     Map<int, List<SourceLocation>> uriMap =
         sourceLocationMap.putIfAbsent(sourceLocation.sourceUri, () => {});
     List<SourceLocation> lineList =
         uriMap.putIfAbsent(sourceLocation.line, () => []);
     lineList.add(sourceLocation);
   });
   sourceLocationMap.forEach((Uri uri, Map<int, List<SourceLocation>> uriMap) {
     SourceFile sourceFile = sourceFileManager.getSourceFile(uri);
     StringBuffer codeBuffer = new StringBuffer();

     int firstLineIndex;
     int lastLineIndex;

     void flush() {
       if (firstLineIndex != null && lastLineIndex != null) {
         dartCodeBuffer.write(
             '<h4>${uri.pathSegments.last}, '
             '${firstLineIndex - windowSize + 1}-'
             '${lastLineIndex + windowSize + 1}'
             '</h4>\n');
         dartCodeBuffer.write('<pre>\n');
         for (int line = firstLineIndex - windowSize;
              line < firstLineIndex;
              line++) {
           if (line >= 0) {
             dartCodeBuffer.write(lineNumber(line));
             dartCodeBuffer.write(sourceFile.getLineText(line));
           }
         }
         dartCodeBuffer.write(codeBuffer);
         for (int line = lastLineIndex + 1;
              line <= lastLineIndex + windowSize;
              line++) {
           if (line < sourceFile.lines) {
             dartCodeBuffer.write(lineNumber(line));
             dartCodeBuffer.write(sourceFile.getLineText(line));
           }
         }
         dartCodeBuffer.write('</pre>\n');
         firstLineIndex = null;
         lastLineIndex = null;
       }
       codeBuffer.clear();
     }

     List<int> lineIndices = uriMap.keys.toList()..sort();
     lineIndices.forEach((int lineIndex) {
       List<SourceLocation> locations = uriMap[lineIndex];
       if (lastLineIndex != null &&
           lastLineIndex + windowSize * 4 < lineIndex) {
         flush();
       }
       if (firstLineIndex == null) {
         firstLineIndex = lineIndex;
       } else {
         for (int line = lastLineIndex + 1; line < lineIndex; line++) {
           codeBuffer.write(lineNumber(line));
           codeBuffer.write(sourceFile.getLineText(line));
         }
       }
       String line = sourceFile.getLineText(lineIndex);
       locations.sort((a, b) => a.offset.compareTo(b.offset));
       for (int i = 0; i < locations.length; i++) {
         SourceLocation sourceLocation = locations[i];
         int index = collection.getIndex(sourceLocation);
         int start = sourceLocation.column;
         int end = line.length;
         if (i + 1 < locations.length) {
           end = locations[i + 1].column;
         }
         if (i == 0) {
           codeBuffer.write(lineNumber(lineIndex));
           codeBuffer.write(line.substring(0, start));
         }
         codeBuffer.write(
             '<a name="${index}" style="background:${toPattern(index)};" '
             'title="[${lineIndex + 1},${start + 1}]" '
             'onmouseover="highlight(\'$index\');" '
             'onmouseout="highlight();">');
         codeBuffer.write(line.substring(start, end));
         codeBuffer.write('</a>');
       }
       lastLineIndex = lineIndex;
     });

     flush();
   });
   String display = showAsBlock ? 'block' : 'none';
   return '''
 <div name="$name" class="dart-buffer" style="display:$display;">
 <h3>Dart code for: ${escape(name)}</h3>
 ${dartCodeBuffer}
 </div>''';
 }

 /// Computes a HTML visualization of the [codePoints].
 String computeJsTraceHtmlPart(List<CodePoint> codePoints,
                               SourceLocationCollection collection) {
   StringBuffer buffer = new StringBuffer();
   buffer.write('<table style="width:100%;">');
   buffer.write(
       '<tr><th>Node kind</th><th>JS code @ offset</th>'
       '<th>Dart code @ mapped location</th><th>file:position:name</th></tr>');
   codePoints.forEach((CodePoint codePoint) {
     String jsCode = codePoint.jsCode;
     if (codePoint.sourceLocation != null) {
       int index = collection.getIndex(codePoint.sourceLocation);
       if (index != null) {
         String style = '';
         if (!codePoint.isMissing) {
           style = 'style="background:${toColorCss(index)};" ';
         }
         buffer.write('<tr $style'
                      'name="trace$index" '
                      'onmouseover="highlight([${index}]);"'
                      'onmouseout="highlight([]);">');
       } else {
         buffer.write('<tr>');
         print('${codePoint.sourceLocation} not found in ');
         collection.sourceLocationIndexMap.keys
             .where((l) => l.sourceUri == codePoint.sourceLocation.sourceUri)
             .forEach((l) => print(' $l'));
       }
     } else {
       buffer.write('<tr>');
     }
     buffer.write('<td>${codePoint.kind}</td>');
     buffer.write('<td class="code">${jsCode}</td>');
     if (codePoint.sourceLocation == null) {
       //buffer.write('<td></td>');
     } else {
       buffer.write('<td class="code">${codePoint.dartCode}</td>');
       buffer.write('<td>${escape(codePoint.sourceLocation.shortText)}</td>');
     }
     buffer.write('</tr>');
   });
   buffer.write('</table>');

   return buffer.toString();
 }
	// Copyright (c) 2015, 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.

	/// Helper for creating HTML visualization of the source map information
	/// generated by a [SourceMapProcessor].

	library sourcemap.html.helper;

	import 'dart:convert';

	import 'package:compiler/src/io/source_file.dart';
	import 'package:compiler/src/io/source_information.dart';
	import 'package:compiler/src/js/js.dart' as js;

	import 'colors.dart';
	import 'sourcemap_helper.dart';
	import 'sourcemap_html_templates.dart';

	/// Returns the [index]th color for visualization.
	HSV toColor(int index) {
	int hueCount = 24;
	double h = 360.0 * (index % hueCount) / hueCount;
	double v = 1.0;
	double s = 0.5;
	return new HSV(h, s, v);
	}

	/// Return the CSS color value for the [index]th color.
	String toColorCss(int index) {
	return toColor(index).toCss;
	}

	/// Return the CSS color value for the [index]th span.
	String toPattern(int index) {
	/// Use gradient on spans to visually identify consecutive spans mapped to the
	/// same source location.
	HSV startColor = toColor(index);
	HSV endColor = new HSV(startColor.h, startColor.s + 0.4, startColor.v - 0.2);
	return 'linear-gradient(to right, ${startColor.toCss}, ${endColor.toCss})';
	}

	/// Return the html for the [index] line number.
	String lineNumber(int index) {
	return '<span class="lineNumber">${index + 1} </span>';
	}

	/// Return the html escaped [text].
	String escape(String text) {
	return const HtmlEscape().convert(text);
	}

	/// Information needed to generate HTML for a single [SourceMapInfo].
	class SourceMapHtmlInfo {
	final SourceMapInfo sourceMapInfo;
	final CodeProcessor codeProcessor;
	final SourceLocationCollection sourceLocationCollection;

	SourceMapHtmlInfo(this.sourceMapInfo,
	this.codeProcessor,
	this.sourceLocationCollection);
	}

	/// A collection of source locations.
	///
	/// Used to index source locations for visualization and linking.
	class SourceLocationCollection {
	List<SourceLocation> sourceLocations = [];
	Map<SourceLocation, int> sourceLocationIndexMap;

	SourceLocationCollection([SourceLocationCollection parent])
	: sourceLocationIndexMap =
	parent == null ? {} : parent.sourceLocationIndexMap;

	int registerSourceLocation(SourceLocation sourceLocation) {
	return sourceLocationIndexMap.putIfAbsent(sourceLocation, () {
	sourceLocations.add(sourceLocation);
	return sourceLocationIndexMap.length;
	});
	}

	int getIndex(SourceLocation sourceLocation) {
	return sourceLocationIndexMap[sourceLocation];
	}
	}

	/// Processor that computes the HTML representation of a block of JavaScript
	/// code and collects the source locations mapped in the code.
	class CodeProcessor {
	int lineIndex = 0;
	final String onclick;
	int currentJsSourceOffset = 0;
	final SourceLocationCollection collection;
	final Map<int, List<SourceLocation>> codeLocations = {};

	CodeProcessor(this.onclick, this.collection);

	void addSourceLocation(int targetOffset, SourceLocation sourceLocation) {
	codeLocations.putIfAbsent(targetOffset, () => []).add(sourceLocation);
	collection.registerSourceLocation(sourceLocation);
	}

	String convertToHtml(String text) {
	StringBuffer htmlBuffer = new StringBuffer();
	int offset = 0;
	int lineIndex = 0;
	bool pendingSourceLocationsEnd = false;
	htmlBuffer.write(lineNumber(lineIndex));
	SourceLocation currentLocation;

	void endCurrentLocation() {
	if (currentLocation != null) {
	htmlBuffer.write('</a>');
	}
	currentLocation = null;
	}

	void addSubstring(int until) {
	if (until <= offset) return;

	String substring = text.substring(offset, until);
	offset = until;
	bool first = true;
	for (String line in substring.split('\n')) {
	if (!first) {
	endCurrentLocation();
	htmlBuffer.write('\n');
	lineIndex++;
	htmlBuffer.write(lineNumber(lineIndex));
	}
	htmlBuffer.write(escape(line));
	first = false;
	}
	}

	void insertSourceLocations(List<SourceLocation> lastSourceLocations) {
	endCurrentLocation();

	String color;
	int index;
	String title;
	if (lastSourceLocations.length == 1) {
	SourceLocation sourceLocation = lastSourceLocations.single;
	if (sourceLocation != null) {
	index = collection.getIndex(sourceLocation);
	color = "background:${toPattern(index)};";
	title = sourceLocation.shortText;
	currentLocation = sourceLocation;
	}
	} else {

	index = collection.getIndex(lastSourceLocations.first);
	StringBuffer sb = new StringBuffer();
	double delta = 100.0 / (lastSourceLocations.length);
	double position = 0.0;

	void addColor(String color) {
	sb.write(', ${color} ${position.toInt()}%');
	position += delta;
	sb.write(', ${color} ${position.toInt()}%');
	}

	for (SourceLocation sourceLocation in lastSourceLocations) {
	if (sourceLocation == null) continue;
	int colorIndex = collection.getIndex(sourceLocation);
	addColor('${toColorCss(colorIndex)}');
	currentLocation = sourceLocation;
	}
	color = 'background: linear-gradient(to right${sb}); '
	'background-size: 10px 10px;';
	title = lastSourceLocations.map((l) => l.shortText).join(',');
	}
	if (index != null) {
	Set<int> indices =
	lastSourceLocations.map((l) => collection.getIndex(l)).toSet();
	String onmouseover = indices.map((i) => '\'$i\'').join(',');
	htmlBuffer.write(
	'<a name="js$index" href="#${index}" style="$color" title="$title" '
	'onclick="${onclick}" onmouseover="highlight([${onmouseover}]);"'
	'onmouseout="highlight([]);">');
	pendingSourceLocationsEnd = true;
	}
	if (lastSourceLocations.last == null) {
	endCurrentLocation();
	}
	}

	for (int targetOffset in codeLocations.keys.toList()..sort()) {
	List<SourceLocation> sourceLocations = codeLocations[targetOffset];
	addSubstring(targetOffset);
	insertSourceLocations(sourceLocations);
	}

	addSubstring(text.length);
	endCurrentLocation();
	return htmlBuffer.toString();
	}
	}

	/// Computes the HTML representation for a collection of JavaScript code blocks.
	String computeJsHtml(Iterable<SourceMapHtmlInfo> infoList) {

	StringBuffer jsCodeBuffer = new StringBuffer();
	for (SourceMapHtmlInfo info in infoList) {
	String name = info.sourceMapInfo.name;
	String html = info.codeProcessor.convertToHtml(info.sourceMapInfo.code);
	String onclick = 'show(\'$name\');';
	jsCodeBuffer.write(
	'<h3 onclick="$onclick">JS code for: ${escape(name)}</h3>\n');
	jsCodeBuffer.write('''
	<pre>
	$html
	</pre>
	''');
	}
	return jsCodeBuffer.toString();
	}

	/// Computes the HTML representation of the source mapping information for a
	/// collection of JavaScript code blocks.
	String computeJsTraceHtml(Iterable<SourceMapHtmlInfo> infoList) {
	StringBuffer jsTraceBuffer = new StringBuffer();
	for (SourceMapHtmlInfo info in infoList) {
	String name = info.sourceMapInfo.name;
	String jsTrace = computeJsTraceHtmlPart(
	info.sourceMapInfo.codePoints, info.sourceLocationCollection);
	jsTraceBuffer.write('''
	<div name="$name" class="js-trace-buffer" style="display:none;">
	<h3>Trace for: ${escape(name)}</h3>
	$jsTrace
	</div>
	''');
	}
	return jsTraceBuffer.toString();
	}

	/// Computes the HTML information for the [info].
	SourceMapHtmlInfo createHtmlInfo(SourceLocationCollection collection,
	SourceMapInfo info) {
	js.Node node = info.node;
	String code = info.code;
	String name = info.name;
	String onclick = 'show(\'$name\');';
	SourceLocationCollection subcollection =
	new SourceLocationCollection(collection);
	CodeProcessor codeProcessor = new CodeProcessor(onclick, subcollection);
	for (js.Node node in info.nodeMap.nodes) {
	info.nodeMap[node].forEach(
	(int targetOffset, List<SourceLocation> sourceLocations) {
	for (SourceLocation sourceLocation in sourceLocations) {
	codeProcessor.addSourceLocation(targetOffset, sourceLocation);
	}
	});
	}
	return new SourceMapHtmlInfo(info, codeProcessor, subcollection);
	}

	/// Outputs a HTML file in [jsMapHtmlUri] containing an interactive
	/// visualization of the source mapping information in [infoList] computed
	/// with the [sourceMapProcessor].
	void createTraceSourceMapHtml(Uri jsMapHtmlUri,
	SourceMapProcessor sourceMapProcessor,
	Iterable<SourceMapInfo> infoList) {
	SourceFileManager sourceFileManager = sourceMapProcessor.sourceFileManager;
	SourceLocationCollection collection = new SourceLocationCollection();
	List<SourceMapHtmlInfo> htmlInfoList = <SourceMapHtmlInfo>[];
	for (SourceMapInfo info in infoList) {
	htmlInfoList.add(createHtmlInfo(collection, info));
	}

	String jsCode = computeJsHtml(htmlInfoList);
	String dartCode = computeDartHtml(sourceFileManager, htmlInfoList);

	String jsTraceHtml = computeJsTraceHtml(htmlInfoList);
	outputJsDartTrace(jsMapHtmlUri, jsCode, dartCode, jsTraceHtml);
	print('Trace source map html generated: $jsMapHtmlUri');
	}

	/// Computes the HTML representation for the Dart code snippets referenced in
	/// [infoList].
	String computeDartHtml(
	SourceFileManager sourceFileManager,
	Iterable<SourceMapHtmlInfo> infoList) {

	StringBuffer dartCodeBuffer = new StringBuffer();
	for (SourceMapHtmlInfo info in infoList) {
	dartCodeBuffer.write(computeDartHtmlPart(info.sourceMapInfo.name,
	sourceFileManager, info.sourceLocationCollection));
	}
	return dartCodeBuffer.toString();

	}

	/// Computes the HTML representation for the Dart code snippets in [collection].
	String computeDartHtmlPart(String name,
	SourceFileManager sourceFileManager,
	SourceLocationCollection collection,
	{bool showAsBlock: false}) {
	const int windowSize = 3;
	StringBuffer dartCodeBuffer = new StringBuffer();
	Map<Uri, Map<int, List<SourceLocation>>> sourceLocationMap = {};
	collection.sourceLocations.forEach((SourceLocation sourceLocation) {
	Map<int, List<SourceLocation>> uriMap =
	sourceLocationMap.putIfAbsent(sourceLocation.sourceUri, () => {});
	List<SourceLocation> lineList =
	uriMap.putIfAbsent(sourceLocation.line, () => []);
	lineList.add(sourceLocation);
	});
	sourceLocationMap.forEach((Uri uri, Map<int, List<SourceLocation>> uriMap) {
	SourceFile sourceFile = sourceFileManager.getSourceFile(uri);
	StringBuffer codeBuffer = new StringBuffer();

	int firstLineIndex;
	int lastLineIndex;

	void flush() {
	if (firstLineIndex != null && lastLineIndex != null) {
	dartCodeBuffer.write(
	'<h4>${uri.pathSegments.last}, '
	'${firstLineIndex - windowSize + 1}-'
	'${lastLineIndex + windowSize + 1}'
	'</h4>\n');
	dartCodeBuffer.write('<pre>\n');
	for (int line = firstLineIndex - windowSize;
	line < firstLineIndex;
	line++) {
	if (line >= 0) {
	dartCodeBuffer.write(lineNumber(line));
	dartCodeBuffer.write(sourceFile.getLineText(line));
	}
	}
	dartCodeBuffer.write(codeBuffer);
	for (int line = lastLineIndex + 1;
	line <= lastLineIndex + windowSize;
	line++) {
	if (line < sourceFile.lines) {
	dartCodeBuffer.write(lineNumber(line));
	dartCodeBuffer.write(sourceFile.getLineText(line));
	}
	}
	dartCodeBuffer.write('</pre>\n');
	firstLineIndex = null;
	lastLineIndex = null;
	}
	codeBuffer.clear();
	}

	List<int> lineIndices = uriMap.keys.toList()..sort();
	lineIndices.forEach((int lineIndex) {
	List<SourceLocation> locations = uriMap[lineIndex];
	if (lastLineIndex != null &&
	lastLineIndex + windowSize * 4 < lineIndex) {
	flush();
	}
	if (firstLineIndex == null) {
	firstLineIndex = lineIndex;
	} else {
	for (int line = lastLineIndex + 1; line < lineIndex; line++) {
	codeBuffer.write(lineNumber(line));
	codeBuffer.write(sourceFile.getLineText(line));
	}
	}
	String line = sourceFile.getLineText(lineIndex);
	locations.sort((a, b) => a.offset.compareTo(b.offset));
	for (int i = 0; i < locations.length; i++) {
	SourceLocation sourceLocation = locations[i];
	int index = collection.getIndex(sourceLocation);
	int start = sourceLocation.column;
	int end = line.length;
	if (i + 1 < locations.length) {
	end = locations[i + 1].column;
	}
	if (i == 0) {
	codeBuffer.write(lineNumber(lineIndex));
	codeBuffer.write(line.substring(0, start));
	}
	codeBuffer.write(
	'<a name="${index}" style="background:${toPattern(index)};" '
	'title="[${lineIndex + 1},${start + 1}]" '
	'onmouseover="highlight(\'$index\');" '
	'onmouseout="highlight();">');
	codeBuffer.write(line.substring(start, end));
	codeBuffer.write('</a>');
	}
	lastLineIndex = lineIndex;
	});

	flush();
	});
	String display = showAsBlock ? 'block' : 'none';
	return '''
	<div name="$name" class="dart-buffer" style="display:$display;">
	<h3>Dart code for: ${escape(name)}</h3>
	${dartCodeBuffer}
	</div>''';
	}

	/// Computes a HTML visualization of the [codePoints].
	String computeJsTraceHtmlPart(List<CodePoint> codePoints,
	SourceLocationCollection collection) {
	StringBuffer buffer = new StringBuffer();
	buffer.write('<table style="width:100%;">');
	buffer.write(
	'<tr><th>Node kind</th><th>JS code @ offset</th>'
	'<th>Dart code @ mapped location</th><th>file:position:name</th></tr>');
	codePoints.forEach((CodePoint codePoint) {
	String jsCode = codePoint.jsCode;
	if (codePoint.sourceLocation != null) {
	int index = collection.getIndex(codePoint.sourceLocation);
	if (index != null) {
	String style = '';
	if (!codePoint.isMissing) {
	style = 'style="background:${toColorCss(index)};" ';
	}
	buffer.write('<tr $style'
	'name="trace$index" '
	'onmouseover="highlight([${index}]);"'
	'onmouseout="highlight([]);">');
	} else {
	buffer.write('<tr>');
	print('${codePoint.sourceLocation} not found in ');
	collection.sourceLocationIndexMap.keys
	.where((l) => l.sourceUri == codePoint.sourceLocation.sourceUri)
	.forEach((l) => print(' $l'));
	}
	} else {
	buffer.write('<tr>');
	}
	buffer.write('<td>${codePoint.kind}</td>');
	buffer.write('<td class="code">${jsCode}</td>');
	if (codePoint.sourceLocation == null) {
	//buffer.write('<td></td>');
	} else {
	buffer.write('<td class="code">${codePoint.dartCode}</td>');
	buffer.write('<td>${escape(codePoint.sourceLocation.shortText)}</td>');
	}
	buffer.write('</tr>');
	});
	buffer.write('</table>');

	return buffer.toString();
	}