Function pickClosestFileNode

src/resolution/name-matcher.ts:113–133

* Among several file nodes that all match a bare include/import by basename, * pick the one closest to the referencing file: same directory first, then by * directory-tree proximity, with the same language family as a tiebreak. A * C/C++ `#include "X.h"` (and any bare-filename import) resolves re

(candidates: Node[], ref: UnresolvedRef)

 * including file — not to an arbitrary same-named header on another platform.
 */
function pickClosestFileNode(candidates: Node[], ref: UnresolvedRef): Node {
  const dirOf = (p: string): string => {
    const i = p.lastIndexOf('/');
    return i >= 0 ? p.slice(0, i) : '';
  };
  const refDir = dirOf(ref.filePath);
  const sameDir = candidates.filter((c) => dirOf(c.filePath) === refDir);
  const pool = sameDir.length > 0 ? sameDir : candidates;
  let best = pool[0]!;
  let bestScore = -Infinity;
  for (const c of pool) {
    const score =
      computePathProximity(ref.filePath, c.filePath) +
      (sameLanguageFamily(c.language, ref.language) ? 5 : 0);
    if (score > bestScore) {
      bestScore = score;
      best = c;
    }
  }
  return best;
}

/**
 * Language families that share a type system / runtime, so a same-language-only