Evaluate factory function for initial value

src/QueryBuilderGroup.vue

@@ -208,20 +208,19 @@ export default class QueryBuilderGroup extends Vue implements QueryBuilderGroupI
       throw new Error(`"initialValue" of "${selectedRule.identifier}" must not be an object - use a factory function!`);
     }
 
-    let initialValue: any = null; // null as sensitive default...
-    if (typeof selectedRule.initialValue === 'function') {
-      // Use factory function
-      initialValue = selectedRule.initialValue();
-    }
-
+    let value: any = null; // null as sensitive default...
     if (typeof selectedRule.initialValue !== 'undefined') {
-      // If it exists use the primitive value
-      ({ initialValue } = selectedRule);
+      // If a valid has been passed along, use it
+      value = selectedRule.initialValue;
+    }
+    if (typeof value === 'function') {
+      // initialValue is a factory function
+      value = value();
     }
 
     children.push({
       identifier: selectedRule.identifier,
-      value: initialValue,
+      value,
     } as Rule);
 
     this.$emit(

tests/unit/query-builder.spec.ts

@@ -4,9 +4,15 @@ import QueryBuilder from '@/QueryBuilder.vue';
 import App from '../components/App.vue';
 import QueryBuilderGroup from '@/QueryBuilderGroup.vue';
 import QueryBuilderRule from '@/QueryBuilderRule.vue';
+import { QueryBuilderConfig } from '@/types';
+
+interface QueryBuilderTemplate {
+  value: any,
+  config: QueryBuilderConfig,
+}
 
 describe('Test basic functionality of QueryBuilder.vue', () => {
-  const getTemplate = () => ({
+  const getTemplate = (): QueryBuilderTemplate => ({
     value: null,
     config: {
       operators: [
@@ -114,6 +120,41 @@ describe('Test basic functionality of QueryBuilder.vue', () => {
     });
   });
 
+  it('makes use of an initial value\'s factory function', () => {
+    const initialValue = jest.fn(() => 'Hello World');
+
+    const data = getTemplate();
+    data.config.rules = [
+      {
+        identifier: 'txt',
+        name: 'Text Selection',
+        component: Component,
+        initialValue,
+      },
+    ];
+
+    const app = mount(App, {
+      data() {
+        return data;
+      },
+    });
+    const wrapper = app.find(QueryBuilder);
+
+    // Assert rules are available
+    const rules = wrapper.find('.query-builder-group__group-control select').findAll('option');
+    const addRuleBtn = wrapper.find('.query-builder-group__rule-adding-button');
+
+    // Assert update has propagated with default value
+    rules.at(1).setSelected();
+    addRuleBtn.trigger('click');
+    expect(wrapper.emittedByOrder()).toHaveLength(1);
+    expect(wrapper.emittedByOrder()[0]).toStrictEqual({
+      name: 'input',
+      args: [{ operatorIdentifier: 'and', children: [{ identifier: 'txt', value: 'Hello World' }] }],
+    });
+    expect(initialValue).toHaveBeenCalled();
+  });
+
   it('deletes a rule', () => {
     const data = () => ({
       query: {