/**
* An IndexedSourceMapConsumer instance represents a parsed source map which
* we can query for information. It differs from BasicSourceMapConsumer in
* that it takes "indexed" source maps (i.e. ones with a "sections" field) as
* input.
*
* The only parameter is a raw source map (either as a JSON string, or already
* parsed to an object). According to the spec for indexed source maps, they
* have the following attributes:
*
* - version: Which version of the source map spec this map is following.
* - file: Optional. The generated file this source map is associated with.
* - sections: A list of section definitions.
*
* Each value under the "sections" field has two fields:
* - offset: The offset into the original specified at which this section
* begins to apply, defined as an object with a "line" and "column"
* field.
* - map: A source map definition. This source map could also be indexed,
* but doesn't have to be.
*
* Instead of the "map" field, it's also possible to have a "url" field
* specifying a URL to retrieve a source map from, but that's currently
* unsupported.
*
* Here's an example source map, taken from the source map spec[0], but
* modified to omit a section which uses the "url" field.
*
* {
* version : 3,
* file: "app.js",
* sections: [{
* offset: {line:100, column:10},
* map: {
* version : 3,
* file: "section.js",
* sources: ["foo.js", "bar.js"],
* names: ["src", "maps", "are", "fun"],
* mappings: "AAAA,E;;ABCDE;"
* }
* }],
* }
*
* [0]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit#heading=h.535es3xeprgt
*/
public IndexedSourceMapConsumer(SourceMapDescription sourceMapDescription)
{
var version = sourceMapDescription.Version;
var sections = sourceMapDescription.Sections;
if (version != Version)
{
throw new Exception($"Unsupported version: {version}");
}
_sources = new ArraySet();
_names = new ArraySet();
var lastOffset = new Offset
{
Line = -1,
Column = 0
};
_sections = sections.Select(s =>
{
if (s.Url != null)
{
// The url field will require support for asynchronicity.
// See https://github.com/mozilla/source-map/issues/16
throw new NotImplementedException("Support for url field in sections not implemented.");
}
var offset = s.Offset;
var offsetLine = s.Offset.Line;
var offsetColumn = s.Offset.Column;
if (offsetLine < lastOffset.Line ||
(offsetLine == lastOffset.Line && offsetColumn < lastOffset.Column))
{
throw new Exception("Section offsets must be ordered and non-overlapping.");
}
lastOffset = offset;
return(new GeneratedSection
{
GeneratedOffset =
new 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 = GetConsumer(s.Map)
});
}).ToList();
}
/**
* A BasicSourceMapConsumer instance represents a parsed source map which we can
* query for information about the original file positions by giving it a file
* position in the generated source.
*
* The only parameter is the raw source map (either as a JSON string, or
* already parsed to an object). According to the spec, source maps have the
* following attributes:
*
* - version: Which version of the source map spec this map is following.
* - sources: An array of URLs to the original source files.
* - names: An array of identifiers which can be referrenced by individual mappings.
* - sourceRoot: Optional. The URL root from which all sources are relative.
* - sourcesContent: Optional. An array of contents of the original source files.
* - mappings: A string of base64 VLQs which contain the actual mappings.
* - file: Optional. The generated file this source map is associated with.
*
* Here is an example source map, taken from the source map spec[0]:
*
* {
* version : 3,
* file: "out.js",
* sourceRoot : "",
* sources: ["foo.js", "bar.js"],
* names: ["src", "maps", "are", "fun"],
* mappings: "AA,AB;;ABCDE;"
* }
*
* [0]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit?pli=1#
*/
public BasicSourceMapConsumer(SourceMapDescription sourceMapDescription)
{
var sourceMapDescription1 = sourceMapDescription;
int version = sourceMapDescription1.Version;
string[] sources = sourceMapDescription1.Sources;
// Sass 3.3 leaves out the 'names' array, so we deviate from the spec (which
// requires the array) to play nice here.
var names = sourceMapDescription1.Names ?? new string[0];
var sourceRoot = sourceMapDescription1.SourceRoot;
var sourcesContent = sourceMapDescription1.SourcesContent;
var mappings = sourceMapDescription1.Mappings;
// 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 != Version)
{
throw new Exception($"Unsupported version: {version}");
}
sources = Enumerable.Select <string, string>(sources
// 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.
.Select(Util.Normalize), source =>
sourceRoot != null &&
Util.IsAbsolute(sourceRoot) &&
Util.IsAbsolute(source)
? Util.Relative(sourceRoot, source)
: source)
.ToArray();
// 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.
_names = new ArraySet(names, true);
_sources = new ArraySet(sources, true);
SourceRoot = sourceRoot;
SourcesContent = sourcesContent;
_mappings = mappings;
}
public static ISourceMapConsumer GetConsumer(SourceMapDescription sourceMapDescription)
{
return(sourceMapDescription.Sections != null
? (ISourceMapConsumer) new IndexedSourceMapConsumer(sourceMapDescription)
: new BasicSourceMapConsumer(sourceMapDescription));
}