Function resolveGoCrossPackageReference

src/resolution/import-resolver.ts:2014–2062

* Resolve a Go cross-package qualified reference (`pkga.FuncX`) by matching * the package alias against an in-module import, stripping the module prefix * to a project-relative directory, and locating the exported symbol in any * `.go` file under that directory. Returns `null` for stdlib / third-

(
  ref: UnresolvedRef,
  imports: ImportMapping[],
  context: ResolutionContext
)

 * can still try the file-based path.
 */
function resolveGoCrossPackageReference(
  ref: UnresolvedRef,
  imports: ImportMapping[],
  context: ResolutionContext
): ResolvedRef | null {
  const mod = context.getGoModule?.();
  if (!mod) return null;

  // Qualified call: receiver before `.`, member after. A bare reference
  // (no dot) is a same-file/in-package call — handled elsewhere.
  const dotIdx = ref.referenceName.indexOf('.');
  if (dotIdx <= 0) return null;
  const receiver = ref.referenceName.substring(0, dotIdx);
  const memberName = ref.referenceName.substring(dotIdx + 1);
  if (!memberName) return null;

  for (const imp of imports) {
    if (imp.localName !== receiver) continue;
    // Only in-module imports map to a known directory.
    if (imp.source !== mod.modulePath && !imp.source.startsWith(mod.modulePath + '/')) {
      continue;
    }
    const pkgDir = imp.source === mod.modulePath
      ? ''
      : imp.source.substring(mod.modulePath.length + 1);

    // Look up the member by name and pick the candidate whose file lives
    // directly in the package directory. Match the immediate parent dir
    // exactly so a call to `pkga.FuncX` doesn't accidentally land on a
    // `FuncX` declared in `pkga/subpkg/`.
    const candidates = context.getNodesByName(memberName);
    for (const node of candidates) {
      if (node.language !== 'go') continue;
      if (!node.isExported) continue;
      const fp = node.filePath.replace(/\\/g, '/');
      const lastSlash = fp.lastIndexOf('/');
      const fileDir = lastSlash >= 0 ? fp.substring(0, lastSlash) : '';
      if (fileDir === pkgDir) {
        return {
          original: ref,
          targetNodeId: node.id,
          confidence: 0.9,
          resolvedBy: 'import',
        };
      }
    }
  }
  return null;
}

/** Recursive depth cap for re-export chain following. Real codebases
 *  rarely chain barrels more than 2–3 deep; 8 is a generous safety