parseSkinContractDeclaration function

SkinContractDeclaration parseSkinContractDeclaration(String markdown)

Parses a full ## Skin Contract: <name> declaration from a spec markdown: the heading supplies the contract NAME (declaration metadata, never schema data) and the fenced JSON body the contract.

Implementation

SkinContractDeclaration parseSkinContractDeclaration(String markdown) {
  final match = RegExp(
    r'^## Skin Contract:(.*)$',
    multiLine: true,
  ).firstMatch(markdown);
  if (match == null) {
    throw SkinContractParseException(
      'skin contract: no "## Skin Contract:" heading found',
    );
  }
  final name = (match.group(1) ?? '').trim();
  if (name.isEmpty) {
    throw SkinContractParseException(
      'skin contract: the heading must name the contract '
      '("## Skin Contract: <name>")',
    );
  }
  final bodyRegion = markdown.substring(match.end);
  final open = RegExp(
    '^\u0060\u0060\u0060json\\s*\$',
    multiLine: true,
  ).firstMatch(bodyRegion);
  if (open == null) {
    throw SkinContractParseException(
      'skin contract: the "## Skin Contract:" section carries no fenced '
      'JSON body — an empty contract is not a valid contract',
    );
  }
  final close = bodyRegion.indexOf('```', open.end);
  if (close < 0) {
    throw SkinContractParseException(
      'skin contract: the "## Skin Contract:" JSON fence is not closed',
    );
  }
  final contract = parseSkinContractJson(
    bodyRegion.substring(open.end, close).trim(),
  );
  return SkinContractDeclaration(name: name, contract: contract);
}