fix: allow {%render%} to reassign argument, #404

src/builtin/tags/render.ts

@@ -1,3 +1,4 @@
+import { __assign } from 'tslib'
 import { assert } from '../../util/assert'
 import { ForloopDrop } from '../../drop/forloop-drop'
 import { toEnumerable } from '../../util/collection'
@@ -51,12 +52,12 @@ export default {
     assert(filepath, () => `illegal filename "${filepath}"`)
 
     const childCtx = new Context({}, ctx.opts, ctx.sync)
-    const scope = yield hash.render(ctx)
+    const scope = childCtx.bottom()
+    __assign(scope, yield hash.render(ctx))
     if (this['with']) {
       const { value, alias } = this['with']
       scope[alias || filepath] = evalToken(value, ctx)
     }
-    childCtx.push(scope)
 
     if (this['for']) {
       const { value, alias } = this['for']
@@ -67,7 +68,7 @@ export default {
         scope[alias] = item
         const templates = yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])
         yield liquid.renderer.renderTemplates(templates, childCtx, emitter)
-        scope.forloop.next()
+        scope['forloop'].next()
       }
     } else {
       const templates = yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])

src/context/context.ts

@@ -6,9 +6,21 @@ import { isArray, isNil, isString, isFunction, toLiquid } from '../util/undersco
 import { InternalUndefinedVariableError } from '../util/error'
 
 export class Context {
+  /**
+   * insert a Context-level empty scope,
+   * for tags like {% capture %} {% assign %} to operate
+   */
   private scopes: Scope[] = [{}]
   private registers = {}
+  /**
+   * user passed in scope
+   * {% increment %}, {% decrement %} changes this scope,
+   * whereas {% capture %}, {% assign %} only hide this scope
+   */
   public environments: Scope
+  /**
+   * global scope used as fallback for missing variables
+   */
   public globals: Scope
   public sync: boolean
   public opts: NormalizedFullOptions

src/liquid-options.ts

@@ -55,7 +55,7 @@ export interface LiquidOptions {
   greedy?: boolean;
   /** `fs` is used to override the default file-system module with a custom implementation. */
   fs?: FS;
-  /** the global environment passed down to all partial templates, i.e. templates included by `include`, `layout` and `render` tags. */
+  /** the global scope passed down to all partial and layout templates, i.e. templates included by `include`, `layout` and `render` tags. */
   globals?: object;
   /** Whether or not to keep value type when writing the Output, not working for streamed rendering. Defaults to `false`. */
   keepOutputType?: boolean;