fix: only attempt tsc if tsconfig exists

package.json

@@ -81,7 +81,7 @@
     "lint": "eslint . --ext .ts",
     "postpublish": "yarn run clean",
     "posttest": "yarn lint",
-    "postinstall": "husky install",
+    "prepare": "husky install && yarn build",
     "prepublishOnly": "yarn run build && oclif lock && oclif manifest . && oclif readme",
     "pretest": "yarn build && tsc -p test --noEmit",
     "preversion": "yarn run clean",

src/plugins.ts

@@ -88,17 +88,32 @@ export default class Plugins {
         await this.yarn.exec([...add, url], yarnOpts)
         const {dependencies} = await this.pjson()
         name = Object.entries(dependencies ?? {}).find(([, u]) => u === url)![0]
+        const root = join(this.config.dataDir, 'node_modules', name)
         plugin = await Config.load({
           devPlugins: false,
           name,
-          root: join(this.config.dataDir, 'node_modules', name),
+          root,
           userPlugins: false,
         })
         await this.refresh({all: true, prod: true}, plugin.root)
 
         this.isValidPlugin(plugin)
 
         await this.add({name, type: 'user', url})
+
+        if (
+          plugin.getPluginsList().find((p) => p.root === root)?.moduleType === 'module' &&
+          (await fileExists(join(plugin.root, 'tsconfig.json')))
+        ) {
+          try {
+            // CJS plugins can be auto-transpiled at runtime but ESM plugins
+            // cannot. To support ESM plugins we need to compile them after
+            // installing them.
+            await this.yarn.exec(['run', 'tsc'], {...yarnOpts, cwd: plugin.root})
+          } catch (error) {
+            this.debug(error)
+          }
+        }
       } else {
         // npm
         const range = validRange(tag)