routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/enhanced-resolve/lib/getPaths.js

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+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+/** @typedef {import("./Resolver").FileSystem} FileSystem */
+/** @typedef {{ paths: string[], segments: string[] }} GetPathsResult */
+
+/**
+ * Walk `path` from tip to root, returning every ancestor directory (plus the
+ * input itself) in `paths`, and each corresponding segment name in `segments`.
+ *
+ * The return value may be shared across callers via `getPathsCached` — treat
+ * it as read-only. Callers that need to mutate (currently only
+ * `SymlinkPlugin`) should `slice()` the arrays locally before writing.
+ * @param {string} path path
+ * @returns {GetPathsResult} paths and segments
+ */
+function getPaths(path) {
+	if (path === "/") return { paths: ["/"], segments: [""] };
+	const parts = path.split(/(.*?[\\/]+)/);
+	const paths = [path];
+	const segments = [parts[parts.length - 1]];
+	let part = parts[parts.length - 1];
+	path = path.slice(0, Math.max(0, path.length - part.length - 1));
+	for (let i = parts.length - 2; i > 2; i -= 2) {
+		paths.push(path);
+		part = parts[i];
+		path = path.slice(0, Math.max(0, path.length - part.length)) || "/";
+		segments.push(part.slice(0, -1));
+	}
+	[, part] = parts;
+	segments.push(part);
+	paths.push(part);
+	return {
+		paths,
+		segments,
+	};
+}
+
+/**
+ * Per-filesystem memoization of `getPaths`. Kept in a standalone WeakMap
+ * rather than being hung off `resolver.pathCache` so that adding this cache
+ * does not change the hidden-class shape of `pathCache` — which is accessed
+ * on the hot path of every resolve as `resolver.pathCache.{join,dirname,
+ * basename}.fn(...)`. CodSpeed caught that shape change as a ~1–2%
+ * instruction-count regression on `cache-predicate`, so we keep pathCache
+ * shape-stable by owning this cache here instead.
+ *
+ * The cache lifetime is tied to the filesystem object (same invariant as
+ * `_pathCacheByFs` in `Resolver.js`): when the user swaps filesystems the
+ * entries become unreachable and get collected.
+ * @type {WeakMap<FileSystem, Map<string, GetPathsResult>>}
+ */
+const _getPathsCacheByFs = new WeakMap();
+
+/**
+ * Memoized `getPaths`. The returned object is shared across callers — do
+ * not mutate the `paths` or `segments` arrays in-place; `slice()` first if
+ * you need a mutable copy.
+ * @param {FileSystem} fileSystem filesystem used as the cache namespace
+ * @param {string} path path
+ * @returns {GetPathsResult} paths and segments
+ */
+function getPathsCached(fileSystem, path) {
+	let cache = _getPathsCacheByFs.get(fileSystem);
+	if (cache === undefined) {
+		cache = new Map();
+		_getPathsCacheByFs.set(fileSystem, cache);
+	} else {
+		const cached = cache.get(path);
+		if (cached !== undefined) return cached;
+	}
+	const result = getPaths(path);
+	cache.set(path, result);
+	return result;
+}
+
+module.exports = getPaths;
+module.exports.getPathsCached = getPathsCached;