use metric units without custom and none units

Author: Lms24

packages/core/src/attributes.ts

@@ -1,5 +1,5 @@
 import { DEBUG_BUILD } from './debug-build';
-import type { MeasurementUnit } from './types-hoist/measurement';
+import type { DurationUnit, FractionUnit, InformationUnit, MeasurementUnit, NoneUnit } from './types-hoist/measurement';
 import { debug } from './utils/debug-logger';
 
 export type RawAttributes<T> = T & ValidatedAttributes<T>;
@@ -33,13 +33,17 @@ type AttributeUnion = {
   };
 }[keyof AttributeTypeMap];
 
-export type TypedAttributeValue = AttributeUnion & { unit?: MeasurementUnit };
+export type TypedAttributeValue = AttributeUnion & { unit?: AttributeUnit };
 
 export type AttributeObject = {
   value: unknown;
-  unit?: MeasurementUnit;
+  unit?: AttributeUnit;
 };
 
+// Unfortunately, we loose type safety if we did something like Exclude<MeasurementUnit, string>
+// so therefore we unionize between the three supported unit categories.
+type AttributeUnit = DurationUnit | InformationUnit | FractionUnit;
+
 /* If an attribute has either a 'value' or 'unit' property, we use the ValidAttributeObject type. */
 export type ValidatedAttributes<T> = {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any

packages/core/test/lib/scope.test.ts

@@ -221,9 +221,10 @@ describe('Scope', () => {
         });
       });
 
-      it('accepts a custom unit', () => {
+      it('still accepts a custom unit but TS-errors on it', () => {
         // mostly there for type checking purposes.
         const scope = new Scope();
+        /** @ts-expect-error we don't support custom units type-wise but we don't actively block them */
         scope.setAttribute('str', { value: 3, unit: 'inch' });
         expect(scope['_attributes']).toEqual({
           str: { value: 3, unit: 'inch' },