Add proper typing and fix lookup

Got those types from another part of the codebase so hopefully they are
correct, need them for CI to pass.

src/devices/smartwings.ts

@@ -2,17 +2,17 @@ import fz from '../converters/fromZigbee';
 import tz from '../converters/toZigbee';
 import * as exposes from '../lib/exposes';
 import * as reporting from '../lib/reporting';
-import {DefinitionWithExtend} from '../lib/types';
-import {getOptions} from '../lib/utils';
+import {DefinitionWithExtend, Zh} from '../lib/types';
+import {getOptions, assertString, getFromLookup} from '../lib/utils';
 
 
 const backwards_cover_state = {
     key: ['state'],
-    convertSet: async (entity, key, value, meta) => {
+    convertSet: async (entity: Zh.Endpoint, key: string, value: number | string, meta: any) => {
         const lookup = {'open': 'downClose', 'close': 'upOpen', 'stop': 'stop', 'on': 'downClose', 'off': 'upOpen'};
-        utils.assertString(value, key);
+        assertString(value, key);
         value = value.toLowerCase();
-        await entity.command('closuresWindowCovering', lookup[value], {}, getOptions(meta.mapped, entity));
+        await entity.command('closuresWindowCovering', getFromLookup(value, lookup), {}, getOptions(meta.mapped, entity));
     },
 };