fix: nested block for layout

.all-contributorsrc

@@ -14,7 +14,7 @@
       "login": "harttle",
       "name": "Jun Yang",
       "avatar_url": "https://avatars3.githubusercontent.com/u/4427974?v=4",
-      "profile": "https://harttle.land",
+      "profile": "https://github.com/harttle",
       "contributions": [
         "maintenance",
         "code"

.cursor/rules/testing.mdc

@@ -0,0 +1,17 @@
+---
+description: Testing conventions — e2e uses built dist, integration uses src
+globs: test/**/*.ts
+alwaysApply: false
+---
+
+# Testing
+
+## End-to-end tests (`test/e2e`)
+
+- **Use the built package**, not TypeScript sources under `src/`.
+- Import the public API from the package root (for example `import { Liquid } from '../..'`), which resolves through `package.json` to **`dist/`** (`main`, `module`, etc.).
+- **Avoid** `import … from '../../src/liquid'` (or other `src/` paths) in `test/e2e/**` so e2e matches what consumers get from npm and you do not depend on an unbuilt tree.
+
+## Integration and unit tests
+
+- Tests under `test/integration/`, `src/**/*.spec.ts`, and similar may import from **`src/`** when the suite is meant to run against the current TypeScript sources (typical for this repo’s Jest setup).

README.md

@@ -108,7 +108,7 @@ Want to contribute? see [Contribution Guidelines][contribution]. Thanks goes to
 <table>
   <tbody>
     <tr>
-      <td align="center" valign="top" width="14.28%"><a href="https://harttle.land"><img src="https://avatars3.githubusercontent.com/u/4427974?v=4?s=100" width="100px;" alt="Jun Yang"/><br /><sub><b>Jun Yang</b></sub></a><br /><a href="#maintenance-harttle" title="Maintenance">🚧</a> <a href="https://github.com/harttle/liquidjs/commits?author=harttle" title="Code">💻</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/harttle"><img src="https://avatars3.githubusercontent.com/u/4427974?v=4?s=100" width="100px;" alt="Jun Yang"/><br /><sub><b>Jun Yang</b></sub></a><br /><a href="#maintenance-harttle" title="Maintenance">🚧</a> <a href="https://github.com/harttle/liquidjs/commits?author=harttle" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/chenos"><img src="https://avatars0.githubusercontent.com/u/2993310?v=4?s=100" width="100px;" alt="chenos"/><br /><sub><b>chenos</b></sub></a><br /><a href="https://github.com/harttle/liquidjs/commits?author=chenos" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://zachleat.com/"><img src="https://avatars2.githubusercontent.com/u/39355?v=4?s=100" width="100px;" alt="Zach Leatherman"/><br /><sub><b>Zach Leatherman</b></sub></a><br /><a href="https://github.com/harttle/liquidjs/issues?q=author%3Azachleat" title="Bug reports">🐛</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/thardy"><img src="https://avatars3.githubusercontent.com/u/120636?v=4?s=100" width="100px;" alt="Tim Hardy"/><br /><sub><b>Tim Hardy</b></sub></a><br /><a href="https://github.com/harttle/liquidjs/commits?author=thardy" title="Code">💻</a></td>

src/context/context.ts

@@ -48,8 +48,8 @@ export class Context {
     this.memoryLimit = memoryLimit ?? new Limiter('memory alloc', renderOptions.memoryLimit ?? opts.memoryLimit)
     this.renderLimit = renderLimit ?? new Limiter('template render', getPerformance().now() + (renderOptions.renderLimit ?? opts.renderLimit))
   }
-  public getRegister (key: string) {
-    return (this.registers[key] = this.registers[key] || {})
+  public getRegister<T> (key: string, defaultValue: T = undefined as T): T {
+    return (this.registers[key] = this.registers[key] || defaultValue)
   }
   public setRegister (key: string, value: any) {
     return (this.registers[key] = value)

src/tags/block.ts

@@ -23,20 +23,25 @@ export default class extends Tag {
   * render (ctx: Context, emitter: Emitter) {
     const blockRender = this.getBlockRender(ctx)
     if (ctx.getRegister('blockMode') === BlockMode.STORE) {
-      ctx.getRegister('blocks')[this.block] = blockRender
+      ctx.getRegister('blocks', {} as Record<string, any>)[this.block] = blockRender
     } else {
       yield blockRender(new BlockDrop(), emitter)
     }
   }
 
   private getBlockRender (ctx: Context) {
+    const self = this as Tag
     const { liquid, templates } = this
-    const renderChild = ctx.getRegister('blocks')[this.block]
+    const renderChild = ctx.getRegister('blocks', {} as Record<string, any>)[this.block]
     const renderCurrent = function * (superBlock: BlockDrop, emitter: Emitter) {
-      // add {{ block.super }} support when rendering
+      const stack: Tag[] = ctx.getRegister('blockStack', [])
+      if (stack.includes(self)) throw new Error('block tag cannot be nested')
+
+      stack.push(self)
       ctx.push({ block: superBlock })
       yield liquid.renderer.renderTemplates(templates, ctx, emitter)
       ctx.pop()
+      stack.pop()
     }
     return renderChild
       ? (superBlock: BlockDrop, emitter: Emitter) => renderChild(

src/tags/cycle.ts

@@ -27,7 +27,7 @@ export default class extends Tag {
   * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, unknown> {
     const group = (yield evalToken(this.group, ctx)) as ValueToken
     const fingerprint = `cycle:${group}:` + this.candidates.join(',')
-    const groups = ctx.getRegister('cycle')
+    const groups = ctx.getRegister('cycle', {} as Record<string, number>)
     let idx = groups[fingerprint]
 
     if (idx === undefined) {

src/tags/for.ts

@@ -50,7 +50,7 @@ export default class extends Tag {
     }
 
     const continueKey = 'continue-' + this.variable + '-' + this.collection.getText()
-    ctx.push({ continue: ctx.getRegister(continueKey) })
+    ctx.push({ continue: ctx.getRegister(continueKey, {}) })
     const hash = yield this.hash.render(ctx)
     ctx.pop()
 

src/tags/layout.ts

@@ -32,7 +32,7 @@ export default class extends Tag {
     // render remaining contents and store rendered results
     ctx.setRegister('blockMode', BlockMode.STORE)
     const html = yield renderer.renderTemplates(this.templates, ctx)
-    const blocks = ctx.getRegister('blocks')
+    const blocks = ctx.getRegister('blocks', {} as Record<string, any>)
 
     // set whole content to anonymous block if anonymous doesn't specified
     if (blocks[''] === undefined) blocks[''] = (parent: BlankDrop, emitter: Emitter) => emitter.write(html)

test/e2e/parse-and-render.spec.ts

@@ -82,4 +82,39 @@ describe('.parseAndRender()', function () {
       expect(() => e.parseAndRenderSync('{% render "link" %}')).toThrow(/ENOENT|Failed to lookup/)
     })
   })
+  describe('layout: nested {% block %} regression', function () {
+    let root: string
+    beforeEach(function () {
+      root = mkdtempSync(join(tmpdir(), 'liquid-e2e-layout-nested-'))
+    })
+    afterEach(function () {
+      rmSync(root, { recursive: true, force: true })
+    })
+    it('should reject same-name {% block %} nested in child template (no hang / OOM)', async function () {
+      writeFileSync(
+        join(root, 'layout.html'),
+        '<header>{% block a %}default-a{% endblock %}</header>' +
+        '<main>{% block b %}default-b{% endblock %}</main>' +
+        '<footer>{% block c %}default-c{% endblock %}</footer>'
+      )
+      writeFileSync(
+        join(root, 'template.html'),
+        '{% layout "layout" %}' +
+        '{% block a %}outer-a {% block a %}inner-a{% endblock %}{% endblock %}' +
+        '{% block b %}content-b{% endblock %}' +
+        '{% block c %}content-c{% endblock %}'
+      )
+      const liquid = new Liquid({ root, extname: '.html' })
+      await expect(liquid.renderFile('template')).rejects.toThrow(/block tag cannot be nested/)
+    })
+    it('should reject nested anonymous {% block %} in child template (no hang / OOM)', async function () {
+      writeFileSync(join(root, 'parent.html'), 'X{%block%}{%endblock%}Y')
+      writeFileSync(
+        join(root, 'template.html'),
+        '{% layout "parent" %}{%block%}A{%block%}B{%endblock%}{%endblock%}'
+      )
+      const liquid = new Liquid({ root, extname: '.html' })
+      await expect(liquid.renderFile('template')).rejects.toThrow(/block tag cannot be nested/)
+    })
+  })
 })

test/integration/tags/include.spec.ts

@@ -50,7 +50,7 @@ describe('tags/include', function () {
     })
     return liquid.renderFile('/parent.html').catch(function (e) {
       expect(e.name).toBe('TokenizationError')
-      expect(e.message).toMatch('illegal file path, file:/parent.html, line:1, col:11')
+      expect(e.message).toMatch(/illegal file path, file:.*parent.html, line:1, col:11/)
     })
   })
 

test/integration/tags/layout.spec.ts

@@ -166,6 +166,27 @@ describe('tags/layout', function () {
     const html = await liquid.renderFile('/main.html')
     return expect(html).toBe('XAY')
   })
+  it('should reject nested {% block %} with the same name (no OOM / hang)', function () {
+    mock({
+      '/layout.html':
+        '<header>{% block a %}default-a{% endblock %}</header>' +
+        '<main>{% block b %}default-b{% endblock %}</main>' +
+        '<footer>{% block c %}default-c{% endblock %}</footer>',
+      '/template.html':
+        '{% layout "layout" %}' +
+        '{% block a %}outer-a {% block a %}inner-a{% endblock %}{% endblock %}' +
+        '{% block b %}content-b{% endblock %}' +
+        '{% block c %}content-c{% endblock %}'
+    })
+    return expect(liquid.renderFile('/template.html')).rejects.toThrow(/block tag cannot be nested/)
+  })
+  it('should reject nested anonymous {% block %} (no OOM / hang)', function () {
+    mock({
+      '/parent.html': 'X{%block%}{%endblock%}Y'
+    })
+    const src = '{% layout "parent.html" %}{%block%}A{%block%}B{%endblock%}{%endblock%}'
+    return expect(liquid.parseAndRender(src)).rejects.toThrow(/block tag cannot be nested/)
+  })
   it('should not bleed scope into `include` layout', async function () {
     mock({
       '/parent.html': 'X{%block a%}{%endblock%}Y{%block b%}{%endblock%}Z',