/// <summary>
/// Finds the mapping for a generated position to the source position,
/// and, if provided by the source map, source file name and source function names.
/// </summary>
/// <param name="line">Line in the generated JavaScript file</param>
/// <param name="column">Column in the generated JavaScript file</param>
/// <returns></returns>
public SourceMapping SourceMappingFor(uint line, uint column)
{
var mockItem = new SourceMapping()
{
GeneratedLine = line,
GeneratedColumn = column
};
var position = generatedMappings.BinarySearch(mockItem, new CompareGeneratedItems());
if (position < 0)
{
return(generatedMappings[Math.Min(~position, generatedMappings.Count - 1)]);
}
else
{
return(generatedMappings[position]);
}
}
void processSourceMap()
{
if (sourceMap.version != SOURCE_MAP_VERSION)
{
throw new SourceMapParsingException("Invalid source map: version != 3");
}
var numSources = sourceMap.sources.Length;
var numNames = sourceMap.names.Length;
var generatedMappings = new List <SourceMapping>();
uint generatedLine = 0;
uint previousOriginalLine = 0;
uint previousOriginalColumn = 0;
uint previousSource = 0;
uint previousName = 0;
foreach (string line in sourceMap.mappings.Split(';'))
{
generatedLine += 1;
uint previousGeneratedColumn = 0;
foreach (string segment in line.Split(','))
{
var segmentLength = segment.Length;
var fields = new List <int>();
var characterIndex = 0;
while (characterIndex < segmentLength)
{
var field = Base64VLQConverter.Decode(segment.Substring(characterIndex, segmentLength - characterIndex));
fields.Add(field.Result);
characterIndex += field.CharactersRead;
}
var numFields = fields.Count;
if (numFields < 1)
{
continue;
}
if (numFields == 2)
{
throw new SourceMapParsingException("Found a source, but no line and column");
}
if (numFields == 3)
{
throw new SourceMapParsingException("Found a source and line, but no column");
}
previousGeneratedColumn = (uint)(previousGeneratedColumn + fields[0]);
var mapping = new SourceMapping()
{
GeneratedLine = generatedLine,
GeneratedColumn = previousGeneratedColumn
};
if (numFields < 2)
{
mapping.SourceFile = "";
mapping.SourceName = "";
}
else
{
previousSource = (uint)(previousSource + fields[1]);
if (previousSource >= 0 && previousSource < numSources)
{
mapping.SourceFile = sourceMap.sources[previousSource];
}
else
{
throw new SourceMapParsingException($"Invalid source map: reference to source index {previousSource} when source list length is {numSources}");
}
previousOriginalLine = (uint)(previousOriginalLine + fields[2]);
mapping.SourceLine = previousOriginalLine + 1;
previousOriginalColumn = (uint)(previousOriginalColumn + fields[3]);
mapping.SourceColumn = previousOriginalColumn;
if (numFields > 4)
{
previousName = (uint)(previousName + fields[4]);
if (previousName >= 0 && previousName < numNames)
{
mapping.SourceName = sourceMap.names[previousName];
}
else
{
throw new SourceMapParsingException($"Invalid source map: reference to name index {previousName} when name list length is {numNames}");
}
}
else
{
mapping.SourceName = "";
}
}
generatedMappings.Add(mapping);
}
}
if (generatedMappings.Count < 1)
{
throw new SourceMapParsingException("Source map contains no mappings");
}
generatedMappings.Sort(new CompareGeneratedItems());
this.generatedMappings = generatedMappings;
}