From a49584bb66e898f5f90635e05f997b757dfec1fa Mon Sep 17 00:00:00 2001
From: Sergei Startsev <ai@programist.ru>
Date: Fri, 16 Sep 2016 22:44:25 +0300
Subject: [PATCH] fix incorrect concatenation of source maps

---
 lib/output.js     |  76 +++++++++--------------------
 lib/sourcemaps.js | 119 ++++++++++------------------------------------
 2 files changed, 48 insertions(+), 147 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index 3dda1fa..7437e78 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -4,69 +4,39 @@ var fs = require('fs');
 var Promise = require('bluebird');
 var asp = require('bluebird').promisify;
 var extend = require('./utils').extend;
-
 var fromFileURL = require('./utils').fromFileURL;
-var toFileURL = require('./utils').toFileURL;
 
 function countLines(str) {
   return str.split(/\r\n|\r|\n/).length;
 }
 
-// Process compiler outputs, gathering:
-//
-//   concatOutputs:         list of source strings to concatenate
-//   sourceMapsWithOffsets: list of [absolute offset,
-//                                   source map string] pairs
-//
-//  Takes lists as empty references and populates via push.
-function processOutputs(outputs) {
-  var removeSourceMaps = require('./sourcemaps').removeSourceMaps;
-
-  var offset = 0;
-
-  var outputObj = {};
-
-  var sources = outputObj.sources = [];
-  var sourceMapsWithOffsets = outputObj.sourceMapsWithOffsets = [];
-
-  outputs.forEach(function(output) {
-    var source;
-    if (typeof output == 'object') {
-      source = output.source || '';
-      var offset_ = output.sourceMapOffset || 0;
-      var map = output.sourceMap;
-      if (map) {
-        sourceMapsWithOffsets.push([offset + offset_, map]);
-      }
-    }
-    // NB perhaps we should enforce output is always an object down the chain?
-    else if (typeof output == 'string') {
-      source = output;
-    }
-    else {
-      throw "Unexpected output format: " + output.toString();
+function createOutput(outFile, outputs, basePath, sourceMaps, sourceMapContents) {
+  var concatenate = require('./sourcemaps').concatenate;
+  var files = outputs.map(function (el) {
+    if (el.source) {
+      //normalize source urls
+      el.sourceMap.sources = el.sourceMap.sources.map(function (sourceURL) {
+        return sourceURL.replace(/\\/g, "/");
+      });
+      return {
+        code: el.source,
+        map: el.sourceMap
+      };
+    } else {
+      return {
+        code: el,
+        map: undefined
+      };
     }
-    source = removeSourceMaps(source || '');
-    offset += countLines(source);
-    sources.push(source);
   });
-
-  return outputObj;
-}
-
-function createOutput(outFile, outputs, basePath, sourceMaps, sourceMapContents) {
-  var concatenateSourceMaps = require('./sourcemaps').concatenateSourceMaps;
-
-  var outputObj = processOutputs(outputs);
-
-  if (sourceMaps)
-    var sourceMap = concatenateSourceMaps(outFile, outputObj.sourceMapsWithOffsets, basePath, sourceMapContents);
-
-  var output = outputObj.sources.join('\n');
+  //concatenates sources and appropriate source maps
+  var concatenated = concatenate(files, outFile).toStringWithSourceMap({
+    file: path.basename(outFile)
+  });
 
   return {
-    source: output,
-    sourceMap: sourceMap
+    source: concatenated.code,
+    sourceMap: concatenated.map.toString()
   };
 }
 
diff --git a/lib/sourcemaps.js b/lib/sourcemaps.js
index 2e70880..4392699 100644
--- a/lib/sourcemaps.js
+++ b/lib/sourcemaps.js
@@ -1,105 +1,36 @@
 var sourceMap = require('source-map');
+var SourceNode = sourceMap.SourceNode;
+var SourceMapConsumer = sourceMap.SourceMapConsumer;
 var path = require('path');
-var fs = require('fs');
 
-var toFileURL = require('./utils').toFileURL;
-var fromFileURL = require('./utils').fromFileURL;
+exports.concatenate = function(files, outFile) {
+  var concatenated = new SourceNode();
 
-var wrapSourceMap = function(map) {
-  return new sourceMap.SourceMapConsumer(map);
-};
-
-var sourceMapRegEx = /\/\/[@#] ?(sourceURL|sourceMappingURL)=([^\n'"]+)/;
-exports.removeSourceMaps = function(source) {
-  return source.replace(sourceMapRegEx, '');
-};
-
-function getMapObject(map) {
-  if (typeof map != 'string')
-    return map;
-
-  try {
-    return JSON.parse(map);
-  }
-  catch(error) {
-    throw new Error('Invalid JSON: ' + map);
-  }
-}
-
-function isFileURL(url) {
-  return url.substr(0, 8) == 'file:///';
-}
-
-exports.concatenateSourceMaps = function(outFile, mapsWithOffsets, basePath, sourceMapContents) {
-  var generated = new sourceMap.SourceMapGenerator({
-    file: path.basename(outFile)
-  });
-
-  var outPath = path.dirname(outFile);
-
-  var contentsBySource = sourceMapContents ? {} : null;
-
-  mapsWithOffsets.forEach(function(pair) {
-    var offset = pair[0];
-    var map = getMapObject(pair[1]);
-
-    if (sourceMapContents && map.sourcesContent) {
-      for (var i=0; i<map.sources.length; i++) {
-        var source = (map.sourceRoot || '') + map.sources[i];
-        if (!source.match(/\/@traceur/)) {
-          if (!contentsBySource[source]) {
-            contentsBySource[source] = map.sourcesContent[i];
-          } else {
-            if (contentsBySource[source] != map.sourcesContent[i]) {
-              throw new Error("Mismatched sourcesContent for: " + source);
-            }
-          }
-        }
-      }
+  files.forEach(function (file, index) {
+    if (index !== 0) {
+      concatenated.add("\n");
     }
 
-    wrapSourceMap(map).eachMapping(function(mapping) {
-      if (!mapping.originalLine || !mapping.originalColumn || !mapping.source || mapping.source.match(/(\/|^)@traceur/))
-        return;
-
-      generated.addMapping({
-        generated: {
-          line: offset + mapping.generatedLine,
-          column: mapping.generatedColumn
-        },
-        original: {
-          line: mapping.originalLine,
-          column: mapping.originalColumn
-        },
-        source: mapping.source,
-        name: mapping.name
-      });
-    });
-  });
-
-  // normalize source paths and inject sourcesContent if necessary
-  var normalized = JSON.parse(JSON.stringify(generated));
-
-  if (sourceMapContents) {
-    normalized.sourcesContent = normalized.sources.map(function(source) {
-      if (contentsBySource[source])
-        return contentsBySource[source];
-
-      try {
-        return fs.readFileSync(path.resolve(basePath, source)).toString();
-      }
-      catch (e) {
-        return "";
+    var node;
+    var map = file.map;
+    if (map) {
+      if (typeof map.toJSON === "function") {
+        map = map.toJSON();
       }
-    });
-  }
-
-  normalized.sources = normalized.sources.map(function(source) {
-    if (isFileURL(source))
-      source = fromFileURL(source);
+      node = SourceNode.fromStringWithSourceMap(
+        file.code,
+        new SourceMapConsumer(map),
+        path.relative(
+          path.dirname(outFile + ".map"),
+          path.dirname(".")
+        )
+      );
+    } else {
+      node = new SourceNode(null, null, null, file.code);
+    }
 
-    return path.relative(outPath, path.resolve(basePath, source)).replace(/\\/g, '/');
+    concatenated.add(node);
   });
 
-  return JSON.stringify(normalized);
+  return concatenated;
 };