Handlebars.js: Stack blown when nested "@partial-block"-using partial not given a partial block.

[damncabbage]

I just hit this in the wild with someone accidentally calling a @partial-block-using partial without giving it said partial block.

Minimal example:

var Handlebars = require('handlebars');
Handlebars.registerPartial('outer', '<p>{{> @partial-block }}</p>');
Handlebars.registerPartial('inner', '<span>{{> @partial-block }}</span>');

// Calls "inner" without giving it a partial block.
Handlebars.compile("<div>{{#>outer}} {{>inner}} {{/outer}}</div>")(); 

Produces:

RangeError: Maximum call stack size exceeded
    at Object.eval (eval at createFunctionContext (…/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23), <anonymous>:1:10)
    at main (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:173:32)
    at ret (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:176:12)
    at ret (…/node_modules/handlebars/dist/cjs/handlebars/compiler/compiler.js:525:21)
    at Object.invokePartial (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:268:12)
    at Object.invokePartialWrapper [as invokePartial] (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:68:39)
    at eval (eval at createFunctionContext (…/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23), <anonymous>:6:28)
    at prog (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:219:12)
    at Object.invokePartial (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:268:12)
    at Object.invokePartialWrapper [as invokePartial] (…/node_modules/handlebars/dist/cjs/handlebars/runtime.js:68:39)

As far as I can tell: the inner partial, when not giving a partial-block of its own, will refer to the @partial-block given to the outer partial.

Tested with Handlebars 4.0.5.

[stringbean]

This also affects inline partials. JSFiddle showing this.

[jaichandra]

Nested partials is critical to building modular templates. This needs to be addressed on priority. Any workarounds?

[damncabbage]

@jaichandra: I think there may be some confusion: this bug is triggered by accidentally not providing a needed partial-block when calling a partial; in this case, Handlebars goes and uses a different partial-block.

It should result an error in all cases, just not this error.

(Nested partials, when called correctly, work fine; there shouldn't be a need for a workaround.)

[jaichandra]

@damncabbage: Ok. May be im confused. Here is an example of what I am trying to do.

item.hbs

<div class="item-text">
{{> @partial-block}}
</div>

list-item.hbs

<div class="list-item">
{{#> item}}
{{> @partial-block}}
{{/item}}
</div>

usage:

{{#> list-item}}
<span>Item name</span>
{{/list-item}}

I got RangeError: Maximum call stack size exceeded error.

Does this work?

[damncabbage]

@jaichandra: I'm treating these as separate bug reports (same symptom, but no idea if it's the same cause), but yes, your example breaks for me with latest-stable.

My all-inline-partials example for ease:

{{#*inline "outer" }}
  {{#>inner}}
    <p>{{> @partial-block }}</p>
  {{/inner}}
{{/inline}}

{{#*inline "inner" }}
  <div>{{> @partial-block }}</div>
{{/inline}}

{{#>outer}}
  Hello
{{/outer}}

[lawnsea]

@damncabbage I believe that #1243 fixes this bug as well.

[Dangoo]

After building the sources and integrating the version built from 7535e48 I get this error:

events.js:160
      throw er; // Unhandled 'error' event
      ^
Error: The partial @partial-block could not be found
    at Object.invokePartial (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:255:11)
    at Object.invokePartialWrapper [as invokePartial] (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:65:39)
    at Object.eval (eval at createFunctionContext (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:252:23), <anonymous>:14:28)
    at main (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:170:32)
    at Object.ret (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:173:12)
    at Object.lsg-demo-section (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/compiler/compiler.js:467:21)
    at Object.invokePartialWrapper [as invokePartial] (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:69:46)
    at eval (eval at createFunctionContext (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:252:23), <anonymous>:5:31)
    at prog (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/runtime.js:206:12)
    at execIteration (<PROJEKT_ROOT>/node_modules/handlebars/dist/cjs/handlebars/helpers/each.js:42:19)

/cc @lawnsea @wycats

[lawnsea]

@Dangoo do you get this error with one of the templates from this issue? If not, please post a template the reproduces the error you're seeing.

[Dangoo]

@lawnsea No, the given examples work flawlessly.
The error is caused by a custom helper in our project (Styleguide-Thingy) wich injects the generated markup inside a markup tab (using @partial-block).
Sometimes the output of that generator is empty so my first guess was that this would cause the error.

But using @damncabbage example while leaving the content of {{#>outer}} empty produces no error - as expected.

The strange thing is, that it worked with 4.0.5 and breaks with the master state.
But I believe it's likely an issue on our side.

May you please tag/publish a new release then (compiling the master each time is no fun… 😛 )?

[nknapp]

I just verified that this issue is fixed in 4.0.6 (the original issue). @Dangoo Could you open a new issue if the error you wrote about in https://github.com/wycats/handlebars.js/issues/1185#issuecomment-246627746 is not on your side?