fix: elsif is not supported for unless, fixes #268

src/builtin/tags/unless.ts

@@ -1,8 +1,9 @@
-import { TopLevelToken, Template, Emitter, Expression, isFalsy, ParseStream, Context, TagImplOptions, Token, TagToken } from '../../types'
+import { TopLevelToken, Template, Emitter, Expression, isTruthy, isFalsy, ParseStream, Context, TagImplOptions, TagToken } from '../../types'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
     this.templates = []
+    this.branches = []
     this.elseTemplates = []
     let p
     const stream: ParseStream = this.liquid.parser.parseStream(remainTokens)
@@ -10,6 +11,12 @@ export default {
         p = this.templates
         this.cond = tagToken.args
       })
+      .on('tag:elsif', (token: TagToken) => {
+        this.branches.push({
+          cond: token.args,
+          templates: p = []
+        })
+      })
       .on('tag:else', () => (p = this.elseTemplates))
       .on('tag:endunless', () => stream.stop())
       .on('template', (tpl: Template) => p.push(tpl))
@@ -23,8 +30,20 @@ export default {
   render: function * (ctx: Context, emitter: Emitter) {
     const r = this.liquid.renderer
     const cond = yield new Expression(this.cond, ctx.opts.lenientIf).value(ctx)
-    yield (isFalsy(cond, ctx)
-      ? r.renderTemplates(this.templates, ctx, emitter)
-      : r.renderTemplates(this.elseTemplates, ctx, emitter))
+
+    if (isFalsy(cond, ctx)) {
+      yield r.renderTemplates(this.templates, ctx, emitter)
+      return
+    }
+
+    for (const branch of this.branches) {
+      const cond = yield new Expression(branch.cond, ctx.opts.lenientIf).value(ctx)
+      if (isTruthy(cond, ctx)) {
+        yield r.renderTemplates(branch.templates, ctx, emitter)
+        return
+      }
+    }
+
+    yield r.renderTemplates(this.elseTemplates, ctx, emitter)
   }
 } as TagImplOptions

src/render/boolean.ts

@@ -5,10 +5,9 @@ export function isTruthy (val: any, ctx: Context): boolean {
 }
 
 export function isFalsy (val: any, ctx: Context): boolean {
-  if(ctx.opts.jsTruthy) {
+  if (ctx.opts.jsTruthy) {
     return !val
-  }
-  else {
+  } else {
     return val === false || undefined === val || val === null
   }
 }

test/e2e/issues.ts

@@ -42,4 +42,16 @@ describe('Issues', function () {
     const html = engine.parseAndRenderSync(template)
     expect(html).to.equal('This is a code snippet showing how {% breaks the raw block.')
   })
+  it('#268 elsif is not supported for unless', () => {
+    const template = `{%- unless condition1 -%}
+    <div>X</div>
+    {%- elsif condition2 -%}
+        <div>Y</div>
+    {%- else %}
+        <div>Z</div>
+    {% endunless %}`
+    const engine = new Liquid()
+    const html = engine.parseAndRenderSync(template, { condition1: true, condition2: true })
+    expect(html).to.equal('<div>Y</div>')
+  })
 })

test/integration/builtin/tags/if.ts

@@ -1,5 +1,9 @@
 import { Liquid } from '../../../../src/liquid'
-import { expect } from 'chai'
+import * as chai from 'chai'
+import * as chaiAsPromised from 'chai-as-promised'
+
+const expect = chai.expect
+chai.use(chaiAsPromised)
 
 describe('tags/if', function () {
   const liquid = new Liquid()

test/integration/builtin/tags/unless.ts

@@ -14,6 +14,11 @@ describe('tags/unless', function () {
     const html = await liquid.parseAndRender(src)
     return expect(html).to.equal('no')
   })
+  it('should support elsif', async function () {
+    const src = '{% unless true %}1{%elsif true%}2{%else%}3{%endunless%}'
+    const html = await liquid.parseAndRender(src)
+    return expect(html).to.equal('2')
+  })
   it('should render unless when predicate yields false', async function () {
     const src = '{% unless false %}yes{%else%}no{%endunless%}'
     const html = await liquid.parseAndRender(src)