Small adjustments after #37 and added test case

Author: Damian Dulisz

src/multiselectMixin.js

@@ -241,12 +241,12 @@ module.exports = {
   },
   computed: {
     filteredOptions () {
-      let search = this.search ? this.search : ''
-      var options = this.hideSelected
+      let search = this.search || ''
+      let options = this.hideSelected
         ? this.options.filter(this.isNotSelected)
         : this.options
-      options = this.$options.filters.filterBy(options, search)
-      if (this.taggable && search.length > 0 && !this.isExistingOption(search)) {
+      options = this.$options.filters.filterBy(options, this.search)
+      if (this.taggable && search.length && !this.isExistingOption(search)) {
         options.unshift({ isTag: true, label: search })
       }
       return options

test/unit/specs/Multiselect.spec.js

@@ -148,6 +148,18 @@ describe('Multiselect.vue', () => {
           expect(vm.$children[0].search).to.equal(2)
           expect(vm.$children[0].$els.search.value).to.equal('2')
         })
+        it('if selected is null should set search value to empty string', () => {
+          const vm = new Vue({
+            template: '<multiselect :selected="value" :options="source" label="id" key="id" :taggable="true"></multiselect>',
+            components: { Multiselect },
+            data: {
+              value: null,
+              source: [1, 2, 3]
+            }
+          }).$mount()
+          expect(vm.$children[0].search).to.equal(null)
+          expect(vm.$children[0].$els.search.value).to.equal('')
+        })
       })
     })
     describe('when searchable == FALSE', () => {