libs directory, default main function

src/loader.js

@@ -0,0 +1,26 @@
+'use strict';
+
+/*
+ * ESM loader hook registered from 'main.js' via `module.register()`.
+ * It resolves '@lib/<name>' specifiers against the project's '.gral/lib'
+ * directory, supplied through the `data` option of `register()`.
+ */
+
+import * as path from 'path';
+import { pathToFileURL } from 'url';
+
+const LIB_PREFIX = '@lib/';
+
+let libDir = null;
+
+export function initialize(data) {
+  libDir = data && data.libDir ? data.libDir : null;
+}
+
+export async function resolve(specifier, context, nextResolve) {
+  if (libDir && specifier.startsWith(LIB_PREFIX)) {
+    const target = path.join(libDir, specifier.slice(LIB_PREFIX.length));
+    return { url: pathToFileURL(target).href, shortCircuit: true };
+  }
+  return nextResolve(specifier, context);
+}

src/main.js

@@ -19,12 +19,14 @@
 
 import * as fs from 'fs';
 import * as path from 'path';
+import { register } from 'node:module';
 import Horde from './horde.js';
 import run from './run.js';
 
 const CONFIG_DIR = '.gral';
 const CONFIG_FILE = 'config.json';
 const FUNCTIONS_DIR = 'functions';
+const LIB_DIR = 'lib';
 
 const DEFAULT_CONFIG = {
   host: 'wss://hub.hordelab.com',
@@ -211,12 +213,12 @@ async function main(argv) {
   let config = loadConfig(root);
   Gral.path = root;
 
+  // Make '.gral/lib/*' importable from function modules via '@lib/<name>'.
+  const libDir = path.join(root, CONFIG_DIR, LIB_DIR);
+  await register('./loader.js', import.meta.url, { data: { libDir } });
+
   const functions = await loadFunctions(root);
-
-  let horde = new Horde({host: config.host, token: config.token});
-  await horde.connect();
-
-  Gral.horde = horde;
+  Gral.horde = new Horde({host: config.host, token: config.token});
 
   if (command.help) {
     console.log(HELP);
@@ -234,15 +236,20 @@ async function main(argv) {
     return 0;
   }
 
-  if (!command.functionName) {
-    console.error('Error: a function name is required.');
-    console.error(HELP);
-    return 1;
+  let fname = command.functionName;
+  if (!fname) {
+    if (functions.has('main')) {
+      fname = 'main';
+    } else {
+      console.error('Error: a function name is required.');
+      console.error(HELP);
+      return 1;
+    }
   }
 
-  const fn = functions.get(command.functionName);
+  const fn = functions.get(fname);
   if (!fn) {
-    console.error(`Error: unknown function '${command.functionName}'.`);
+    console.error(`Error: unknown function '${fname}'.`);
     return 1;
   }
 
@@ -253,6 +260,9 @@ async function main(argv) {
 
   const input = { prompt: command.prompt };
 
+  // Connect before executing
+  await Gral.horde.connect();
+
   try {
     await fn(input);
   } catch (err) {