feat(config): import mud config with tsx (#3290)

.changeset/calm-dodos-care.md

@@ -0,0 +1,5 @@
+---
+"@latticexyz/config": patch
+---
+
+Replaced esbuild with tsx to load MUD config in an effort to resolve issues with loading multiple MUD configs in parallel.

packages/config/package.json

@@ -43,8 +43,8 @@
     "@ark/util": "0.2.2",
     "@latticexyz/common": "workspace:*",
     "@latticexyz/schema-type": "workspace:*",
-    "esbuild": "^0.17.15",
-    "find-up": "^6.3.0"
+    "find-up": "^6.3.0",
+    "tsx": "^4.19.1"
   },
   "devDependencies": {
     "tsup": "^6.7.0",

packages/config/src/deprecated/node/loadConfig.ts

@@ -1,41 +1,31 @@
 import { findUp } from "find-up";
 import path from "path";
-import esbuild from "esbuild";
-import { rmSync } from "fs";
 import { pathToFileURL } from "url";
 import os from "os";
-
-// TODO: explore using https://www.npmjs.com/package/ts-import instead
+import fs from "fs/promises";
+import { tsImport } from "tsx/esm/api";
+import { require as tsRequire } from "tsx/cjs/api";
 
 // In order of preference files are checked
 /** @deprecated */
 const configFiles = ["mud.config.js", "mud.config.mjs", "mud.config.ts", "mud.config.mts"];
-/** @deprecated */
-const TEMP_CONFIG = "mud.config.temp.mjs";
 
 /** @deprecated */
 export async function loadConfig(configPath?: string): Promise<unknown> {
   configPath = await resolveConfigPath(configPath);
-  try {
-    await esbuild.build({
-      entryPoints: [configPath],
-      format: "esm",
-      outfile: TEMP_CONFIG,
-      // https://esbuild.github.io/getting-started/#bundling-for-node
-      platform: "node",
-      // bundle local imports (otherwise it may error, js can't import ts)
-      bundle: true,
-      // avoid bundling external imports (it's unnecessary and esbuild can't handle all node features)
-      packages: "external",
-    });
-    configPath = await resolveConfigPath(TEMP_CONFIG, true);
-    // Node.js caches dynamic imports, so without appending a cache breaking
-    // param like `?update={Date.now()}` this import always returns the same config
-    // if called multiple times in a single process, like the `dev-contracts` cli
-    return (await import(configPath + `?update=${Date.now()}`)).default;
-  } finally {
-    rmSync(TEMP_CONFIG, { force: true });
+  // load nearest package.json to figure out if we need to import with ESM or CJS
+  const packageJsonPath = await findUp("package.json", { cwd: path.dirname(configPath) });
+  if (!packageJsonPath) throw new Error(`Could not find package.json for config at "${configPath}".`);
+  const packageJson = JSON.parse(await fs.readFile(packageJsonPath, "utf8"));
+  // use require if cjs
+  if (!packageJson.type || packageJson.type === "commonjs") {
+    // tsRequire has an internal cache, so we need to append data to reload the config
+    // this helps with things like the mud dev runner that reevalutes the config on changes
+    return tsRequire(`${configPath}?update=${Date.now()}`, import.meta.url).default;
   }
+  // otherwise default to esm
+  // this is not cached, so we don't need to append anything to the config path
+  return (await tsImport(configPath, import.meta.url)).default;
 }
 
 /** @deprecated */