Nested #if / #each generates TypeError

[davidkellerman]

Here's a short example that generates the error:

var handlebars = require('handlebars');

var template = handlebars.compile(
    '{{#each files.primary as |file|}}\n\
    {{{file.oldFile}}} {{{file.newFile}}}\n\
    {{/each}}\n\
    {{#if files.secondary.length}}\n\
    {{#each files.secondary as |file|}}\n\
    {{{file.oldFile}}} {{{file.newFile}}}\n\
    {{/each}}\n\
    {{/if}}');

var config = {
    files: {
        primary: [ { oldFile: 'old.txt', newFile: 'new.txt' } ],
        secondary: [ { oldFile: 'old.txt', newFile: 'new.txt' } ] }
    };

var rslt = template(config);

console.log(rslt);

Run in node, it produces this console output:

undefined:6
    + ((stack1 = alias1(((stack1 = blockParams[0][0]) != null ? stack1.oldFile : stack1), depth0)) != null ? stack1 : "")
                                              ^

TypeError: Cannot read property '0' of undefined
    at eval (eval at createFunctionContext (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23), <anonymous>:6:47)
    at prog (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/runtime.js:219:12)
    at execIteration (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/helpers/each.js:51:19)
    at Object.<anonymous> (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/helpers/each.js:61:13)
    at eval (eval at createFunctionContext (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23), <anonymous>:5:34)
    at Object.prog [as fn] (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/runtime.js:219:12)
    at Object.<anonymous> (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/helpers/if.js:19:22)
    at Object.eval (eval at createFunctionContext (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23), <anonymous>:6:32)
    at main (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/runtime.js:173:32)
    at ret (/www.nls.com/nodejs/usr-share-nodejs/www/util/printkit-config/node_modules/handlebars/dist/cjs/handlebars/runtime.js:176:12)

Any of these changes cause the error to go away:

1. Removing the first #each clause from the template
2. Removing the #if clause from the template
3. Removing the {{{file.oldFile}}} expansion from the second #each clause, or replacing it with {{oldFile}}

Here's a fiddle with essentially the same example. The console output reports a slightly different error (in Firefox: TypeError: blockParams is undefined).

[nikjuice]

Have the same issue, put a comment here -
#1250

[nknapp]

Does this issue still exist? If it had the same cause as #1250, it should have been fixed in the meantime (i.e. since 4.0.6). If it is related to #1300, it is probably still there. Could anybody check?

[davidkellerman]

I ran the example again. Fails with 4.0.5; succeeds with 4.0.6. Thanks!