Function csharpProjectUsings

src/resolution/name-matcher.ts:4245–4280

* The ` ` of the project files from `dir` up, and the * `global using X;` of each project's own files — a global using is its * project's alone: serilog's Serilog.Tests and Serilog.PerformanceTests each * `global using` their own `Support` namespace, and both define `Some`. *

(dir: string, context: ResolutionContext, memo: Map<string, { usings: Set<string>; project: boolean }>)

 * `project` says whether a `.csproj` sits at `dir` or above it.
 */
function csharpProjectUsings(dir: string, context: ResolutionContext, memo: Map<string, { usings: Set<string>; project: boolean }>): { usings: Set<string>; project: boolean } {
  const key = dir;
  const hit = memo.get(key);
  if (hit) return hit;
  const root = dir === '.' || dir === '' || dir === '/';
  const parent = root ? null : csharpProjectUsings(path.posix.dirname(dir), context, memo);
  const usings = new Set<string>(parent?.usings ?? []);
  let project = parent?.project ?? false;
  let entries: string[] = [];
  try {
    entries = fs.readdirSync(path.join(context.getProjectRoot(), root ? '' : dir));
  } catch {
    entries = [];
  }
  for (const entry of entries) {
    if (!/\.(?:csproj|props)$/i.test(entry)) continue;
    let text = '';
    try {
      text = fs.readFileSync(path.join(context.getProjectRoot(), root ? '' : dir, entry), 'utf8');
    } catch {
      continue;
    }
    if (/\.csproj$/i.test(entry) && !project) {
      project = true;
      for (const u of csharpGlobalUsings(root ? '.' : dir, context)) usings.add(u);
    }
    for (const m of text.matchAll(/<Using\s+Include\s*=\s*"([\w.]+)"(?![^>]*\bStatic\s*=\s*"true")[^>]*>/gi)) usings.add(m[1]!);
    // The SDK's implicit usings (serilog's own `System.TimeProvider` polyfill is seen through them).
    if (/<ImplicitUsings>\s*(?:enable|true)\s*<\/ImplicitUsings>/i.test(text)) {
      for (const ns of CSHARP_IMPLICIT_USINGS) usings.add(ns);
    }
  }
  const result = { usings, project };
  memo.set(key, result);
  return result;
}

const CSHARP_GLOBAL_USINGS = new WeakMap<ResolutionContext, Map<string, Set<string>>>();