fix: allow quoted variable name in capture, fixes #252

src/builtin/tags/capture.ts

@@ -1,9 +1,10 @@
 import { Tokenizer, assert, Template, Context, TagImplOptions, TagToken, TopLevelToken } from '../../types'
+import { evalQuotedToken } from '../../render/expression'
 
 export default {
   parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
     const tokenizer = new Tokenizer(tagToken.args)
-    this.variable = tokenizer.readWord().content
+    this.variable = readVariableName(tokenizer)
     assert(this.variable, () => `${tagToken.args} not valid identifier`)
 
     this.templates = []
@@ -22,3 +23,10 @@ export default {
     ctx.bottom()[this.variable] = html
   }
 } as TagImplOptions
+
+function readVariableName (tokenizer: Tokenizer) {
+  const word = tokenizer.readWord().content
+  if (word) return word
+  const quoted = tokenizer.readQuoted()
+  if (quoted) return evalQuotedToken(quoted)
+}

test/e2e/issues.ts

@@ -10,4 +10,12 @@ describe('Issues', function () {
     const html = engine.parseAndRenderSync('{{huh | truncate: 11}}', { huh: 'fdsafdsafdsafdsaaaaa' })
     expect(html).to.equal('fdsafdsa...')
   })
+  it('#252 "Not valid identifier" error for a quotes-containing identifier', async () => {
+    const template = `{% capture "form_classes" -%}
+      foo
+    {%- endcapture %}{{form_classes}}`
+    const engine = new Liquid()
+    const html = await engine.parseAndRender(template)
+    expect(html).to.equal('foo')
+  })
 })

test/integration/builtin/tags/capture.ts

@@ -13,6 +13,12 @@ describe('tags/capture', function () {
     return expect(html).to.equal('A')
   })
 
+  it('should support quoted variable name', async function () {
+    const src = '{% capture "f" %}{{"a" | capitalize}}{%endcapture%}{{f}}'
+    const html = await liquid.parseAndRender(src)
+    return expect(html).to.equal('A')
+  })
+
   it('should shading rather than overwriting', async function () {
     const src = '{% capture var %}10{% endcapture %}{{var}}'
     const ctx = { 'var': 20 }