fix: explicitly set zero exit code

bin/cmd.js

@@ -5,7 +5,14 @@ import { pickLanguages, pickKeys } from './../lib/util.js'
 import { execCmd } from './../lib/exec.js'
 
 ;(async () => {
-  const [source, target, ...entities] = process.argv.slice(2)
+  const args = process.argv.slice(2)
+  const [source, target, ...entities] = args
+  if (!source || !target || !entities.length) {
+    throw new Error(
+      `Expected at least 3 positional arguments to be given, but got ${args.length}, cannot continue.`
+    )
+  }
+
   const sourceRepo = new WikibaseRepo(source)
   const targetRepo = new WikibaseRepo(target, {
     oauth: {
@@ -27,11 +34,11 @@ import { execCmd } from './../lib/exec.js'
   return `Sucessfully transferred ${entities.length} entities from ${source} to ${target}.`
 })()
   .then((result) => {
-    if (result) {
-      console.log(result)
-    }
+    console.log(result)
+    process.exitCode = 0
   })
   .catch((err) => {
+    console.error('An error occurred executing the command:')
     console.error(err)
     process.exitCode = 1
   })