data, test: refactor utilities into own file

Primarily for more precies test coverage mapping, but also to make
navigation a bit easier and consolidate complex functions with
lots of imports out of the same space as other, more simple or
otherwise specialized files.

1 files changed, 23 insertions, 0 deletions

diff --git a/src/data/composite/wiki-data/inputThingClass.js b/src/data/composite/wiki-data/inputThingClass.js
new file mode 100644
index 0000000..d70480e
--- /dev/null
+++ b/src/data/composite/wiki-data/inputThingClass.js
@@ -0,0 +1,23 @@
+// Please note that this input, used in a variety of #composite/wiki-data
+// utilities, is basically always a kludge. Any usage of it depends on
+// referencing Thing class values defined outside of the #composite folder.
+
+import {input} from '#composite';
+import {isType} from '#validators';
+
+// TODO: Kludge.
+import Thing from '../../things/thing.js';
+
+export default function inputThingClass() {
+  return input.staticValue({
+    validate(thingClass) {
+      isType(thingClass, 'function');
+
+      if (!Object.hasOwn(thingClass, Thing.referenceType)) {
+        throw new TypeError(`Expected a Thing constructor, missing Thing.referenceType`);
+      }
+
+      return true;
+    },
+  });
+}