fix: print expression if it is resolved as null or undefined

ktsn · Apr 29, 2018 · a4ace5c · a4ace5c
1 parent c84f20b
commit a4ace5c
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Showing 2 changed files with 8 additions and 7 deletions.
diff --git a/src/view/components/Expression.vue b/src/view/components/Expression.vue
@@ -1,7 +1,7 @@
 <script lang="ts">
 import Vue, { VNode } from 'vue'
 import { DefaultValue } from '@/parser/script/types'
-import { evalWithScope } from '../eval'
+import { evalWithScope, EvalSuccess } from '../eval'
 
 export default Vue.extend({
   name: 'Expression',
@@ -22,15 +22,16 @@ export default Vue.extend({
   render(h, { props }): VNode {
     const { expression: exp, scope } = props
     const result = evalWithScope(exp, scope)
-    const str = result.isSuccess
-      ? toStringForPrint(result.value)
+    const resolved = result.isSuccess && result.value != null
+    const str = resolved
+      ? toStringForPrint((result as EvalSuccess).value)
       : '{{ ' + exp + ' }}'
 
     return h(
       'span',
       {
         class: {
-          unresolved: !result.isSuccess
+          unresolved: !resolved
         }
       },
       [str]

diff --git a/test/view/VueComponent/basic.spec.ts b/test/view/VueComponent/basic.spec.ts
@@ -53,7 +53,7 @@ describe('VueComponent basic', () => {
     expect(wrapper.find('p').text()).toBe('This is replaced text')
   })
 
-  it('should print an empty string if the expression is resolved as null or undefined', () => {
+  it('should print an expression if it is resolved as null or undefined', () => {
     // prettier-ignore
     const template = createTemplate([
       h('div', [], [
@@ -80,8 +80,8 @@ describe('VueComponent basic', () => {
         }
       ]
     )
-    expect(wrapper.find('#foo').text()).toBe('')
-    expect(wrapper.find('#bar').text()).toBe('')
+    expect(wrapper.find('#foo').text()).toBe('{{ foo }}')
+    expect(wrapper.find('#bar').text()).toBe('{{ bar }}')
   })
 
   it('should add class', () => {