There should be a configuration option to throw if a tag finds no match in the source

[christothes]

Given data with a missing property represented in the source, it should be configurable to have this throw.

var source = 'Some text {{foo}} with {{missing}} tag';
var template = Handlebars.compile(source);
var data = { foo : 'bar'};

//should optionally throw
var result = template(data); 

[showell]

I agree with this request. My workaround for now is that I have a utility that can extract the required data structure from a template, which I can then use to validate the data, rather than making it the job of the compiler. See the gist here: https://gist.github.com/showell/7793101

[rgould]

👍 (I would say that this should be the default)

[abritinthebay]

I'd say the default should be a warning, maybe with console.warn if available, not an error; but the concept is great.

[Baccanno]

Mustache already has a test mechanism {{#here}} my stuff is {{here}} {{/here}}
{{^here}} my stuff is not here {{/here}}

Plus it does not match mustach specs. Why not an option, certainly not a warning or a default behaviour IMO.

[abritinthebay]

One idea could be a simple tester:

var source = 'Some text {{foo}} with {{missing}} tag';
var template = Handlebars.compile(source);
var data = { foo : 'bar'};

if (Handlebars.hasAllProperties(template, data)) {
    var result = template(data); 
}

That way it's not core to the rest of the Handlebars code, allows the ability to test schema's against an actual template, and keeps current behavior.

Only issue I can see is that the compiler may need to be changed to allow collation of the variables.

[kpdecker]

Closing in favor of #932

[ajs139]

Converted @showell's gist to TypeScript, in case it helps anyone: https://gist.github.com/ajs139/f84ccbe5678ef1497a53965cc326b452