How to get pubspec dependencies' SourceRange?

[minhnt3]

I am developing a lint rule related to the pubspec.yaml file but I don't know how can I report errors

class AvoidUsingPubVersionConstraint extends DartLintRule {
  const AvoidUsingPubVersionConstraint() : super(code: _code);

  static const _code = LintCode(
    name: 'avoid_using_pub_version_constraint',
    problemMessage:
        'Avoid using pub version constraint like ^ and any. Please use exact version instead',
  );

  @override
  void run(
    CustomLintResolver resolver,
    ErrorReporter reporter,
    CustomLintContext context,
  ) {
    context.pubspec.dependencies.forEach((key, value) {
      if (_isUsingPubVersionConstraint(value)) {
        reporter.reportErrorForElement(code, value); <------ HERE
      }
    });
  }

  bool _isUsingPubVersionConstraint(Dependency dependency) {
    if (dependency is HostedDependency) {
      return dependency.version.isAny ||
          dependency.version.isEmpty ||
          dependency.toString().startsWith('^');
    }

    return false;
  }

  @override
  List<Fix> getFixes() => [
        RemoveVersionConstraint(),
      ];
}

[rrousselGit]

custom_lint doesn't expose ways to parse YAML natively.

If you want to obtain the "ast" of a pubspec, you'll need to create a custom YamlLintRule which relies on https://pub.dev/packages/yaml
That package parses yaml in a way that exposes the offset/length of everything in a yaml file.