add types to parseSnak function

Author: maxlath

src/helpers/parse_snak.ts

@@ -1,5 +1,8 @@
 import { wikibaseTimeToEpochTime, wikibaseTimeToISOString, wikibaseTimeToSimpleDay } from './time.js'
 import type { TimeInputValue } from './time.js'
+import type { DataType } from '../types/claim.js'
+import type { SimplifySnakOptions } from '../types/simplify_claims.js'
+import type { SnakValue } from '../types/snakvalue.js'
 
 const simple = datavalue => datavalue.value
 
@@ -105,9 +108,9 @@ for (const [ datatype, parser ] of Object.entries(parsers)) {
   normalizedParsers[normalizeDatatype(datatype)] = parser
 }
 
-export function parseSnak (datatype, datavalue, options) {
+export function parseSnak (datatype: DataType | void, datavalue: SnakValue, options: SimplifySnakOptions) {
   // Known case of missing datatype: form.claims, sense.claims, mediainfo.statements
-  datatype = datatype || datavalue.type
+  datatype = (datatype || datavalue.type) as DataType
 
   try {
     // Known case requiring normalization