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
   }
 }