feat(cli): add command helpers and NotAPlayerError

packs/BP/scripts/classes/Commands/lib/commandError.js

@@ -0,0 +1,9 @@
+import { CustomCommandStatus } from '@minecraft/server';
+import { NotAPlayerError } from '../../Errors/NotAPlayerError';
+
+export function commandError(source, err) {
+    if (err instanceof NotAPlayerError) {
+        return { status: CustomCommandStatus.Failure, message: 'construct.commands.error.notAPlayer' };
+    }
+    throw err;
+}

packs/BP/scripts/classes/Commands/lib/findInstance.js

@@ -0,0 +1,12 @@
+import { system } from '@minecraft/server';
+import { structureCollection } from '../../Structure/StructureCollection';
+
+export function findInstance(source, name) {
+    if (!structureCollection.has(name)) {
+        system.run(() => source.sendMessage({
+            rawtext: [{ translate: 'construct.commands.error.instanceNotFound', with: [name] }]
+        }));
+        return null;
+    }
+    return structureCollection.get(name);
+}

packs/BP/scripts/classes/Commands/lib/requirePlayer.js

@@ -0,0 +1,8 @@
+import { PlayerCommandOrigin } from '../PlayerCommandOrigin';
+import { NotAPlayerError } from '../../Errors/NotAPlayerError';
+
+export function requirePlayer(source) {
+    if (!(source instanceof PlayerCommandOrigin))
+        throw new NotAPlayerError();
+    return source.getSource();
+}