Sync constructors, backported to 0.7.3

lib/read-wasm.js

@@ -15,6 +15,10 @@ module.exports = function readWasm() {
     });
   });
 };
+module.exports.sync = function readWasmSync() {
+  const wasmPath = path.join(__dirname, "mappings.wasm");
+  return fs.readFileSync(wasmPath).buffer;
+};
 
 module.exports.initialize = _ => {
   console.debug("SourceMapConsumer.initialize is a no-op when running in node.js");

lib/source-map-consumer.js

@@ -16,13 +16,7 @@ const INTERNAL = Symbol("smcInternal");
 
 class SourceMapConsumer {
   constructor(aSourceMap, aSourceMapURL) {
-    // If the constructor was called by super(), just return Promise<this>.
-    // Yes, this is a hack to retain the pre-existing API of the base-class
-    // constructor also being an async factory function.
-    if (aSourceMap == INTERNAL) {
-      return Promise.resolve(this);
-    }
-
+    if (aSourceMap === INTERNAL) return this;
     return _factory(aSourceMap, aSourceMapURL);
   }
 
@@ -198,74 +192,71 @@ exports.SourceMapConsumer = SourceMapConsumer;
  */
 class BasicSourceMapConsumer extends SourceMapConsumer {
   constructor(aSourceMap, aSourceMapURL) {
-    return super(INTERNAL).then(that => {
-      let sourceMap = aSourceMap;
-      if (typeof aSourceMap === "string") {
-        sourceMap = util.parseSourceMapInput(aSourceMap);
-      }
+    super(INTERNAL);
+    let sourceMap = aSourceMap;
+    if (typeof aSourceMap === "string") {
+      sourceMap = util.parseSourceMapInput(aSourceMap);
+    }
 
-      const version = util.getArg(sourceMap, "version");
-      let sources = util.getArg(sourceMap, "sources");
-      // Sass 3.3 leaves out the 'names' array, so we deviate from the spec (which
-      // requires the array) to play nice here.
-      const names = util.getArg(sourceMap, "names", []);
-      let sourceRoot = util.getArg(sourceMap, "sourceRoot", null);
-      const sourcesContent = util.getArg(sourceMap, "sourcesContent", null);
-      const mappings = util.getArg(sourceMap, "mappings");
-      const file = util.getArg(sourceMap, "file", null);
-
-      // Once again, Sass deviates from the spec and supplies the version as a
-      // string rather than a number, so we use loose equality checking here.
-      if (version != that._version) {
-        throw new Error("Unsupported version: " + version);
-      }
+    const version = util.getArg(sourceMap, "version");
+    let sources = util.getArg(sourceMap, "sources");
+    // Sass 3.3 leaves out the 'names' array, so we deviate from the spec (which
+    // requires the array) to play nice here.
+    const names = util.getArg(sourceMap, "names", []);
+    let sourceRoot = util.getArg(sourceMap, "sourceRoot", null);
+    const sourcesContent = util.getArg(sourceMap, "sourcesContent", null);
+    const mappings = util.getArg(sourceMap, "mappings");
+    const file = util.getArg(sourceMap, "file", null);
+
+    // Once again, Sass deviates from the spec and supplies the version as a
+    // string rather than a number, so we use loose equality checking here.
+    if (version != this._version) {
+      throw new Error("Unsupported version: " + version);
+    }
 
-      if (sourceRoot) {
-        sourceRoot = util.normalize(sourceRoot);
-      }
+    if (sourceRoot) {
+      sourceRoot = util.normalize(sourceRoot);
+    }
 
-      sources = sources
-        .map(String)
-        // Some source maps produce relative source paths like "./foo.js" instead of
-        // "foo.js".  Normalize these first so that future comparisons will succeed.
-        // See bugzil.la/1090768.
-        .map(util.normalize)
-        // Always ensure that absolute sources are internally stored relative to
-        // the source root, if the source root is absolute. Not doing this would
-        // be particularly problematic when the source root is a prefix of the
-        // source (valid, but why??). See github issue #199 and bugzil.la/1188982.
-        .map(function(source) {
-          return sourceRoot && util.isAbsolute(sourceRoot) && util.isAbsolute(source)
-            ? util.relative(sourceRoot, source)
-            : source;
-        });
+    sources = sources
+      .map(String)
+      // Some source maps produce relative source paths like "./foo.js" instead of
+      // "foo.js".  Normalize these first so that future comparisons will succeed.
+      // See bugzil.la/1090768.
+      .map(util.normalize)
+      // Always ensure that absolute sources are internally stored relative to
+      // the source root, if the source root is absolute. Not doing this would
+      // be particularly problematic when the source root is a prefix of the
+      // source (valid, but why??). See github issue #199 and bugzil.la/1188982.
+      .map(function(source) {
+        return sourceRoot && util.isAbsolute(sourceRoot) && util.isAbsolute(source)
+          ? util.relative(sourceRoot, source)
+          : source;
+      });
 
-      // Pass `true` below to allow duplicate names and sources. While source maps
-      // are intended to be compressed and deduplicated, the TypeScript compiler
-      // sometimes generates source maps with duplicates in them. See Github issue
-      // #72 and bugzil.la/889492.
-      that._names = ArraySet.fromArray(names.map(String), true);
-      that._sources = ArraySet.fromArray(sources, true);
+    // Pass `true` below to allow duplicate names and sources. While source maps
+    // are intended to be compressed and deduplicated, the TypeScript compiler
+    // sometimes generates source maps with duplicates in them. See Github issue
+    // #72 and bugzil.la/889492.
+    this._names = ArraySet.fromArray(names.map(String), true);
+    this._sources = ArraySet.fromArray(sources, true);
 
-      that._absoluteSources = that._sources.toArray().map(function(s) {
-        return util.computeSourceURL(sourceRoot, s, aSourceMapURL);
-      });
+    this._absoluteSources = this._sources.toArray().map(function(s) {
+      return util.computeSourceURL(sourceRoot, s, aSourceMapURL);
+    });
 
-      that.sourceRoot = sourceRoot;
-      that.sourcesContent = sourcesContent;
-      that._mappings = mappings;
-      that._sourceMapURL = aSourceMapURL;
-      that.file = file;
+    this.sourceRoot = sourceRoot;
+    this.sourcesContent = sourcesContent;
+    this._mappings = mappings;
+    this._sourceMapURL = aSourceMapURL;
+    this.file = file;
 
-      that._computedColumnSpans = false;
-      that._mappingsPtr = 0;
-      that._wasm = null;
+    this._computedColumnSpans = false;
+    this._mappingsPtr = 0;
+    this._wasm = null;
 
-      return wasm().then(w => {
-        that._wasm = w;
-        return that;
-      });
-    });
+    const w = wasm.sync();
+    this._wasm = w;
   }
 
   /**
@@ -383,14 +374,14 @@ class BasicSourceMapConsumer extends SourceMapConsumer {
       },
       () => {
         switch (order) {
-        case SourceMapConsumer.GENERATED_ORDER:
-          this._wasm.exports.by_generated_location(this._getMappingsPtr());
-          break;
-        case SourceMapConsumer.ORIGINAL_ORDER:
-          this._wasm.exports.by_original_location(this._getMappingsPtr());
-          break;
-        default:
-          throw new Error("Unknown order of iteration.");
+          case SourceMapConsumer.GENERATED_ORDER:
+            this._wasm.exports.by_generated_location(this._getMappingsPtr());
+            break;
+          case SourceMapConsumer.ORIGINAL_ORDER:
+            this._wasm.exports.by_original_location(this._getMappingsPtr());
+            break;
+          default:
+            throw new Error("Unknown order of iteration.");
         }
       }
     );
@@ -746,62 +737,56 @@ exports.BasicSourceMapConsumer = BasicSourceMapConsumer;
  */
 class IndexedSourceMapConsumer extends SourceMapConsumer {
   constructor(aSourceMap, aSourceMapURL) {
-    return super(INTERNAL).then(that => {
-      let sourceMap = aSourceMap;
-      if (typeof aSourceMap === "string") {
-        sourceMap = util.parseSourceMapInput(aSourceMap);
-      }
+    super(INTERNAL);
+    let sourceMap = aSourceMap;
+    if (typeof aSourceMap === "string") {
+      sourceMap = util.parseSourceMapInput(aSourceMap);
+    }
 
-      const version = util.getArg(sourceMap, "version");
-      const sections = util.getArg(sourceMap, "sections");
+    const version = util.getArg(sourceMap, "version");
+    const sections = util.getArg(sourceMap, "sections");
 
-      if (version != that._version) {
-        throw new Error("Unsupported version: " + version);
+    if (version != this._version) {
+      throw new Error("Unsupported version: " + version);
+    }
+
+    this._sources = new ArraySet();
+    this._names = new ArraySet();
+    this.__generatedMappings = null;
+    this.__originalMappings = null;
+    this.__generatedMappingsUnsorted = null;
+    this.__originalMappingsUnsorted = null;
+
+    let lastOffset = {
+      line: -1,
+      column: 0
+    };
+    this._sections = sections.map(s => {
+      if (s.url) {
+        // The url field will require support for asynchronicity.
+        // See https://github.com/mozilla/source-map/issues/16
+        throw new Error("Support for url field in sections not implemented.");
       }
+      const offset = util.getArg(s, "offset");
+      const offsetLine = util.getArg(offset, "line");
+      const offsetColumn = util.getArg(offset, "column");
 
-      that._sources = new ArraySet();
-      that._names = new ArraySet();
-      that.__generatedMappings = null;
-      that.__originalMappings = null;
-      that.__generatedMappingsUnsorted = null;
-      that.__originalMappingsUnsorted = null;
+      if (offsetLine < lastOffset.line ||
+        (offsetLine === lastOffset.line && offsetColumn < lastOffset.column)) {
+        throw new Error("Section offsets must be ordered and non-overlapping.");
+      }
+      lastOffset = offset;
 
-      let lastOffset = {
-        line: -1,
-        column: 0
+      const consumer = new SourceMapConsumer(util.getArg(s, "map"), aSourceMapURL);
+      return {
+        generatedOffset: {
+          // The offset fields are 0-based, but we use 1-based indices when
+          // encoding/decoding from VLQ.
+          generatedLine: offsetLine + 1,
+          generatedColumn: offsetColumn + 1
+        },
+        consumer
       };
-      return Promise.all(sections.map(s => {
-        if (s.url) {
-          // The url field will require support for asynchronicity.
-          // See https://github.com/mozilla/source-map/issues/16
-          throw new Error("Support for url field in sections not implemented.");
-        }
-        const offset = util.getArg(s, "offset");
-        const offsetLine = util.getArg(offset, "line");
-        const offsetColumn = util.getArg(offset, "column");
-
-        if (offsetLine < lastOffset.line ||
-            (offsetLine === lastOffset.line && offsetColumn < lastOffset.column)) {
-          throw new Error("Section offsets must be ordered and non-overlapping.");
-        }
-        lastOffset = offset;
-
-        const cons = new SourceMapConsumer(util.getArg(s, "map"), aSourceMapURL);
-        return cons.then(consumer => {
-          return {
-            generatedOffset: {
-              // The offset fields are 0-based, but we use 1-based indices when
-              // encoding/decoding from VLQ.
-              generatedLine: offsetLine + 1,
-              generatedColumn: offsetColumn + 1
-            },
-            consumer
-          };
-        });
-      })).then(s => {
-        that._sections = s;
-        return that;
-      });
     });
   }
 
@@ -926,7 +911,7 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
         }
 
         return (aNeedle.generatedColumn -
-                section.generatedOffset.generatedColumn);
+          section.generatedOffset.generatedColumn);
       });
     const section = this._sections[sectionIndex];
 
@@ -944,8 +929,8 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
         (section.generatedOffset.generatedLine - 1),
       column: needle.generatedColumn -
         (section.generatedOffset.generatedLine === needle.generatedLine
-         ? section.generatedOffset.generatedColumn - 1
-         : 0),
+          ? section.generatedOffset.generatedColumn - 1
+          : 0),
       bias: aArgs.bias
     });
   }
@@ -1014,8 +999,8 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
             (section.generatedOffset.generatedLine - 1),
           column: generatedPosition.column +
             (section.generatedOffset.generatedLine === generatedPosition.line
-             ? section.generatedOffset.generatedColumn - 1
-             : 0)
+              ? section.generatedOffset.generatedColumn - 1
+              : 0)
         };
         return ret;
       }
@@ -1068,8 +1053,8 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
             (section.generatedOffset.generatedLine - 1),
           generatedColumn: mapping.generatedColumn +
             (section.generatedOffset.generatedLine === mapping.generatedLine
-            ? section.generatedOffset.generatedColumn - 1
-            : 0),
+              ? section.generatedOffset.generatedColumn - 1
+              : 0),
           originalLine: mapping.originalLine,
           originalColumn: mapping.originalColumn,
           name
@@ -1122,19 +1107,19 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
    * we are searching for in the given "haystack" of mappings.
    */
   _findMapping(aNeedle, aMappings, aLineName,
-              aColumnName, aComparator, aBias) {
+    aColumnName, aComparator, aBias) {
     // To return the position we are searching for, we must first find the
     // mapping for the given position and then return the opposite position it
     // points to. Because the mappings are sorted, we can use binary search to
     // find the best mapping.
 
     if (aNeedle[aLineName] <= 0) {
       throw new TypeError("Line must be greater than or equal to 1, got "
-                          + aNeedle[aLineName]);
+        + aNeedle[aLineName]);
     }
     if (aNeedle[aColumnName] < 0) {
       throw new TypeError("Column must be greater than or equal to 0, got "
-                          + aNeedle[aColumnName]);
+        + aNeedle[aColumnName]);
     }
 
     return binarySearch.search(aNeedle, aMappings, aComparator, aBias);
@@ -1169,11 +1154,11 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
     const mappings = [];
 
     let index = this._findMapping(needle,
-                                  this._originalMappings,
-                                  "originalLine",
-                                  "originalColumn",
-                                  util.compareByOriginalPositions,
-                                  binarySearch.LEAST_UPPER_BOUND);
+      this._originalMappings,
+      "originalLine",
+      "originalColumn",
+      util.compareByOriginalPositions,
+      binarySearch.LEAST_UPPER_BOUND);
     if (index >= 0) {
       let mapping = this._originalMappings[index];
 
@@ -1205,8 +1190,8 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
         // Since mappings are sorted, this is guaranteed to find all mappings for
         // the line we are searching for.
         while (mapping &&
-               mapping.originalLine === line &&
-               mapping.originalColumn == originalColumn) {
+          mapping.originalLine === line &&
+          mapping.originalColumn == originalColumn) {
           let lastColumn = mapping.lastGeneratedColumn;
           if (this._computedColumnSpans && lastColumn === null) {
             lastColumn = Infinity;
@@ -1244,9 +1229,9 @@ function _factory(aSourceMap, aSourceMapURL) {
   }
 
   const consumer = sourceMap.sections != null
-      ? new IndexedSourceMapConsumer(sourceMap, aSourceMapURL)
-      : new BasicSourceMapConsumer(sourceMap, aSourceMapURL);
-  return Promise.resolve(consumer);
+    ? new IndexedSourceMapConsumer(sourceMap, aSourceMapURL)
+    : new BasicSourceMapConsumer(sourceMap, aSourceMapURL);
+  return consumer;
 }
 
 function _factoryBSM(aSourceMap, aSourceMapURL) {