StackTrace mapStackTrace()

in lib/source_map_stack_trace.dart [21:76]
38 lines of code
12 McCabe index (conditional complexity)

StackTrace mapStackTrace(Mapping sourceMap, StackTrace stackTrace,
    {bool minified = false, Map<String, Uri>? packageMap, Uri? sdkRoot}) {
  if (stackTrace is Chain) {
    return Chain(stackTrace.traces.map((trace) {
      return Trace.from(mapStackTrace(sourceMap, trace,
          minified: minified, packageMap: packageMap, sdkRoot: sdkRoot));
    }));
  }

  var sdkLib = sdkRoot == null ? null : '$sdkRoot/lib';

  var trace = Trace.from(stackTrace);
  return Trace(trace.frames.map((frame) {
    var line = frame.line;
    // If there's no line information, there's no way to translate this frame.
    // We could return it as-is, but these lines are usually not useful anyways.
    if (line == null) return null;

    // If there's no column, try using the first column of the line.
    var column = frame.column ?? 0;

    // Subtract 1 because stack traces use 1-indexed lines and columns and
    // source maps uses 0-indexed.
    var span =
        sourceMap.spanFor(line - 1, column - 1, uri: frame.uri.toString());

    // If we can't find a source span, ignore the frame. It's probably something
    // internal that the user doesn't care about.
    if (span == null) return null;

    var sourceUrl = span.sourceUrl.toString();
    if (sdkLib != null && p.url.isWithin(sdkLib, sourceUrl)) {
      sourceUrl = 'dart:' + p.url.relative(sourceUrl, from: sdkLib);
    } else if (packageMap != null) {
      for (var package in packageMap.keys) {
        var packageUrl = packageMap[package].toString();
        if (!p.url.isWithin(packageUrl, sourceUrl)) continue;

        sourceUrl =
            'package:$package/' + p.url.relative(sourceUrl, from: packageUrl);
        break;
      }
    }

    return Frame(
        Uri.parse(sourceUrl),
        span.start.line + 1,
        span.start.column + 1,
        // If the dart2js output is minified, there's no use trying to prettify
        // its member names. Use the span's identifier if available, otherwise
        // use the minified member name.
        minified
            ? (span.isIdentifier ? span.text : frame.member)
            : _prettifyMember(frame.member!));
  }).whereType<Frame>());
}