parseInput method

List<TemplateInjection> parseInput(CodeSample sample)

Parses the input for the various code and description segments, and returns a set of template injections in the order found.

Implementation

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;
}