Listen to global filter (#282)

* Listen to global filter

* Move options outside of for scope, add test

Author: indykoning

src/MiniSearch.test.js

@@ -1211,6 +1211,21 @@ describe('MiniSearch', () => {
       expect(results.every(({ category }) => category === 'poetry')).toBe(true)
     })
 
+    it('allows to define a default filter upon instantiation', () => {
+      const ms = new MiniSearch({
+        fields: ['title', 'text'],
+        storeFields: ['category'],
+        searchOptions: {
+          filter: ({ category }) => category === 'poetry'
+        }
+      })
+      ms.addAll(documents)
+    
+      const results = ms.search('del')
+      expect(results.length).toBe(1)
+      expect(results.every(({ category }) => category === 'poetry')).toBe(true)
+    })
+
     it('allows customizing BM25+ parameters', () => {
       const ms = new MiniSearch({ fields: ['text'], searchOptions: { bm25: { k: 1.2, b: 0.7, d: 0.5 } } })
       const documents = [
@@ -1802,6 +1817,8 @@ e forse del mio dir poco ti cale`
       expect(results).toHaveLength(1)
     })
 
+
+
     it('respects the custom defaults set in the constructor', () => {
       const ms = new MiniSearch({
         fields: ['title', 'text'],

src/MiniSearch.ts

@@ -1325,6 +1325,9 @@ export default class MiniSearch<T = any> {
    * @param options  Search options. Each option, if not given, defaults to the corresponding value of `searchOptions` given to the constructor, or to the library default.
    */
   search (query: Query, searchOptions: SearchOptions = {}): SearchResult[] {
+    const { searchOptions: globalSearchOptions } = this._options
+    const options = { ...globalSearchOptions, ...searchOptions }
+
     const rawResults = this.executeQuery(query, searchOptions)
     const results = []
 
@@ -1344,16 +1347,15 @@ export default class MiniSearch<T = any> {
       }
 
       Object.assign(result, this._storedFields.get(docId))
-      if (searchOptions.filter == null || searchOptions.filter(result)) {
+      if (options.filter == null || options.filter(result)) {
         results.push(result)
       }
     }
 
     // If it's a wildcard query, and no document boost is applied, skip sorting
     // the results, as all results have the same score of 1
     if (query === MiniSearch.wildcard &&
-      searchOptions.boostDocument == null &&
-      this._options.searchOptions.boostDocument == null) {
+      options.boostDocument == null) {
       return results
     }