Patch createRequire() and loadConfig() to handle builtin modules in the standalone CLI

Author: thecrypticace

src/lib/load-config.ts

@@ -4,6 +4,14 @@ import { transform } from 'sucrase'
 import { Config } from '../../types/config'
 
 let jiti: ReturnType<typeof jitiFactory> | null = null
+
+// @internal
+// This WILL be removed in some future release
+// If you rely on this your stuff WILL break
+export function useCustomJiti(_jiti: ReturnType<typeof jitiFactory>) {
+  jiti = _jiti
+}
+
 function lazyJiti() {
   return (
     jiti ??

standalone-cli/patch-require.js

@@ -0,0 +1,52 @@
+const Module = require("node:module")
+
+/**
+ * @param {Record<string, any>} mods
+ */
+module.exports.patchRequire = function patchRequire(mods, parentCache) {
+  function wrapRequire(origRequire) {
+    return Object.assign(
+      function (id) {
+        // Patch require(…) to return the cached module
+        if (mods.hasOwnProperty(id)) {
+          return mods[id]
+        }
+
+        return origRequire.apply(this, arguments)
+      },
+
+      // Make sure we carry over other properties of the original require(…)
+      origRequire,
+
+      {
+        resolve (id) {
+          // Defer to the "parent" require cache when resolving the module
+          // This also requires that the module be provided as a "native module" to JITI
+
+          // The path returned here is VERY important as it ensures that the `isNativeRe` in JITI
+          // passes which is required for the module to be loaded via the native require(…) function
+          // Thankfully, the regex just means that it needs to be in a node_modules folder which is true
+          // even when bundled using Vercel's `pkg`
+          if (parentCache.hasOwnProperty(id)) {
+            return parentCache[id].filename
+          }
+
+          return origRequire.resolve.apply(this, arguments)
+        }
+      }
+    )
+  }
+
+  let origRequire = Module.prototype.require
+  let origCreateRequire = Module.createRequire
+
+  // We have to augment the default "require" in every module
+  Module.prototype.require = wrapRequire(origRequire)
+
+  // And any "require" created by the "createRequire" method
+  Module.createRequire = function () {
+    return wrapRequire(
+      origCreateRequire.apply(this, arguments)
+    )
+  }
+}

standalone-cli/standalone.js

@@ -1,5 +1,3 @@
-let Module = require('module')
-let origRequire = Module.prototype.require
 let log = require('tailwindcss/lib/util/log').default
 
 let localModules = {
@@ -25,11 +23,36 @@ let localModules = {
   tailwindcss: require('tailwindcss'),
 }
 
-Module.prototype.require = function (id) {
-  if (localModules.hasOwnProperty(id)) {
-    return localModules[id]
-  }
-  return origRequire.apply(this, arguments)
-}
+// Swap out the default JITI implementation with one that has the built-in modules above preloaded as "native modules"
+// NOTE: This uses a private, internal API of Tailwind CSS and is subject to change at any time
+let { useCustomJiti } = require("tailwindcss/lib/lib/load-config")
+let { transform } = require('sucrase')
+
+useCustomJiti(() => require('jiti')(__filename, {
+  interopDefault: true,
+  nativeModules: Object.keys(localModules),
+  transform: (opts) => {
+    return transform(opts.source, {
+      transforms: ['typescript', 'imports'],
+    })
+  },
+}))
+
+let { patchRequire } = require('./patch-require.js')
+patchRequire(
+  // Patch require(…) to return the bundled modules above so they don't need to be installed
+  localModules,
+
+  // Create a require cache that maps module IDs to module objects
+  // This MUST be done before require is patched to handle caching
+  Object.fromEntries(
+    Object.keys(localModules).map((id) => [
+      id,
+      id === '@tailwindcss/line-clamp'
+        ? `node_modules/@tailwindcss/line-clamp/`
+        : require.cache[require.resolve(id)],
+    ])
+  )
+)
 
 require('tailwindcss/lib/cli')