Function resolveMarkdownFileCore

packages/shared/resolve-file.ts:376–435

* Resolve a markdown file path within a project root. * * @param input - User-provided path (absolute, relative, or bare filename) * @param projectRoot - Project root directory to search within

(
	input: string,
	projectRoot: string,
)

 * @param projectRoot - Project root directory to search within
 */
function resolveMarkdownFileCore(
	input: string,
	projectRoot: string,
): ResolveResult {
	const normalizedInput = normalizeUserPathInput(input);
	const searchInput = normalizeSeparators(normalizedInput);
	const isBareFilename = !searchInput.includes("/");
	const targetLookupKey = getLookupKey(searchInput, isBareFilename);

	// Restrict to markdown files
	if (!isSearchableMarkdownPath(normalizedInput)) {
		return { kind: "not_found", input };
	}

	// 1. Absolute path — use as-is (no project root restriction;
	//    the user explicitly typed the full path)
	if (isAbsoluteNormalizedUserPath(normalizedInput)) {
		const absolutePath = resolveAbsolutePath(normalizedInput);
		if (fileExists(absolutePath)) {
			return { kind: "found", path: absolutePath };
		}
		return { kind: "not_found", input };
	}

	// 2. Exact relative path from project root
	const fromRoot = resolve(projectRoot, searchInput);
	if (isWithinProjectRoot(fromRoot, projectRoot) && fileExists(fromRoot)) {
		return { kind: "found", path: fromRoot };
	}

	// 3. Case-insensitive search (only scan markdown files)
	const allFiles: string[] = [];
	walkMarkdownFiles(projectRoot, projectRoot, allFiles, IGNORED_DIRS);
	const matches: string[] = [];

	for (const match of allFiles) {
		const normalizedMatch = normalizeSeparators(match);
		const matchLookupKey = getLookupKey(normalizedMatch, isBareFilename);

		if (matchLookupKey === targetLookupKey) {
			const full = resolve(projectRoot, normalizedMatch);
			if (isWithinProjectRoot(full, projectRoot)) {
				matches.push(full);
			}
		}
	}

	if (matches.length === 1) {
		return { kind: "found", path: matches[0] };
	}
	if (matches.length > 1) {
		const projectRootPrefix = `${normalizeComparablePath(projectRoot)}/`;
		const relative = matches.map((match) =>
			normalizeComparablePath(match).replace(projectRootPrefix, ""),
		);
		return { kind: "ambiguous", input, matches: relative };
	}