List parseInput()

in packages/snippets/lib/snippet_generator.dart [240:298]
56 lines of code
12 McCabe index (conditional complexity)

  List<TemplateInjection> parseInput(CodeSample sample) {
    bool inCodeBlock = false;
    final List<SourceLine> description = <SourceLine>[];
    final List<TemplateInjection> components = <TemplateInjection>[];
    String? language;
    final RegExp codeStartEnd =
        RegExp(r'^\s*```(?<language>[-\w]+|[-\w]+ (?<section>[-\w]+))?\s*$');
    for (final SourceLine line in sample.input) {
      final RegExpMatch? match = codeStartEnd.firstMatch(line.text);
      if (match != null) {
        // If we saw the start or end of a code block
        inCodeBlock = !inCodeBlock;
        if (match.namedGroup('language') != null) {
          language = match[1];
          if (match.namedGroup('section') != null) {
            components.add(TemplateInjection(
                'code-${match.namedGroup('section')}', <SourceLine>[],
                language: language!));
          } else {
            components.add(
                TemplateInjection('code', <SourceLine>[], language: language!));
          }
        } else {
          language = null;
        }
        continue;
      }
      if (!inCodeBlock) {
        description.add(line);
      } else {
        assert(language != null);
        components.last.contents.add(line);
      }
    }
    final List<String> descriptionLines = <String>[];
    bool lastWasWhitespace = false;
    for (final String line in description
        .map<String>((SourceLine line) => line.text.trimRight())) {
      final bool onlyWhitespace = line.trim().isEmpty;
      if (onlyWhitespace && descriptionLines.isEmpty) {
        // Don't add whitespace lines until we see something without whitespace.
        lastWasWhitespace = onlyWhitespace;
        continue;
      }
      if (onlyWhitespace && lastWasWhitespace) {
        // Don't add more than one whitespace line in a row.
        continue;
      }
      descriptionLines.add(line);
      lastWasWhitespace = onlyWhitespace;
    }
    sample.description = descriptionLines.join('\n').trimRight();
    sample.parts = <TemplateInjection>[
      if (sample is SnippetSample)
        TemplateInjection('#assumptions', sample.assumptions),
      ...components,
    ];
    return sample.parts;
  }