Utilities

Low-level helpers exported alongside hashup(). Use them when you want to build your own hashing pipeline — e.g. to share a resolver across many entries, or to hash files that are not reached through a static import graph.

createResolver

function createResolver(): Resolver;

Creates an enhanced-resolve instance preconfigured for the file types hashup supports:

• Extensions: .ts, .tsx, .mts, .js, .jsx, .mjs, .json
• Extension aliases: .js → .ts/.tsx/.js/.jsx, .mjs → .mts/.mjs, .cjs → .cts/.cjs
• Condition names: import, require, node, webpack
• Cached file system (4s TTL)

resolveImport

function resolveImport(
  resolver: Resolver,
  importSource: string, // absolute path of the file doing the import
  importName: string, // the specifier, e.g. "./foo" or "lodash"
): Promise<string | false>;

Resolves a single specifier against the resolver. Returns the absolute path or false if the import cannot be resolved.

extractImports

function extractImports(file: string, content: string): Promise<string[]>;

Parses a file's source with es-module-lexer and returns its static import specifiers. Type-only imports and dynamic imports with non-literal specifiers are excluded.

hashFile

function hashFile(
  file: string,
  cache: Map<string, string[]>,
  resolver: Resolver,
): Promise<string[]>;

Hashes a file and all its transitive static imports. Results are memoized in cache — pass the same Map across multiple calls to dedupe work. On error (file read or parse failure), a warning is logged and an empty array is returned.

createContentHash

function createContentHash(content: string): string;

SHA-256 (hex) of a string.

combineHashes

function combineHashes(hashes: string[]): string;

Folds an array of hex hashes into a single SHA-256 digest by concatenating them and hashing the result. Order-sensitive — pass hashes in a stable order.

Composing Your Own Pipeline

import { createResolver, hashFile, combineHashes } from "@maastrich/hashup";

const resolver = createResolver();
const cache = new Map<string, string[]>();

const entries = ["./src/a.ts", "./src/b.ts"];
const allHashes: string[] = [];

for (const entry of entries) {
  allHashes.push(...(await hashFile(entry, cache, resolver)));
}

const combined = combineHashes(allHashes);