Truthiness

[josh]

Add a few truthiness specs for JSON values: null, strings and numbers.

Edge cases to consider

• 0 - true in Ruby, false in JS
• "" - true in Ruby, false in JS

Should mustache enforce consistency or use whatever the host language defines as true?

[pvande]

Whether or not specific values are considered truthy is deliberately left up to the semantics of the hosting language. To do otherwise exposes developers working with non-X implementations to unexpected and unpredictable behavior.

This does directly imply that the same template and data hash will render (logically) differently in certain environments. To avoid this problem in the spec, all values being used in a boolean comparison use YAML's boolean data type; the JSON representation is expected to behave likewise.

Mustache users are encouraged to be mindful of the target language's concept of "truth" when producing contextual data.

I'm somewhat disinclined to integrate these patches, since the tests themselves seem tautological w.r.t. the definition of truthiness. Is there a particular implementation that seems to disregard non-Boolean values used for sections?