name : cacheInvalidation.js import crypto from 'crypto' import * as sharedState from './sharedState' /** * Calculate the hash of a string. * * This doesn't need to be cryptographically secure or * anything like that since it's used only to detect * when the CSS changes to invalidate the context. * * This is wrapped in a try/catch because it's really dependent * on how Node itself is build and the environment and OpenSSL * version / build that is installed on the user's machine. * * Based on the environment this can just outright fail. * * See https://github.com/nodejs/node/issues/40455 * * @param {string} str */ function getHash(str) { try { return crypto.createHash('md5').update(str, 'utf-8').digest('binary') } catch (err) { return '' } } /** * Determine if the CSS tree is different from the * previous version for the given `sourcePath`. * * @param {string} sourcePath * @param {import('postcss').Node} root */ export function hasContentChanged(sourcePath, root) { let css = root.toString() // We only care about files with @tailwind directives // Other files use an existing context if (!css.includes('@tailwind')) { return false } let existingHash = sharedState.sourceHashMap.get(sourcePath) let rootHash = getHash(css) let didChange = existingHash !== rootHash sharedState.sourceHashMap.set(sourcePath, rootHash) return didChange }