These are excellent tips.

On Sun, Nov 9, 2014 at 4:46 PM, Asim Jalis <[email protected]> wrote:
> Hi Glenn,
>
> I ran into that problem several times. Initially I just gave up. In a second
> iteration I tried to debug the problem by reducing program to get a minimal
> repro of the issue. This proved to be a great learning experience. Here are
> the issues I discovered:
>
> 1. A big source of problems was the :optimizations :advanced. Disabling this
> started producing much more readable messages.
>
> 2. To use jQuery and other external libraries in the browser I needed to
> declare them using :externs in the project.clj.
>
> 3. To use macros in ClojureScript I had to use :require-macros inside (ns
> foo) instead of :require.
>
> By avoiding these gotchas I have been able to avoid the cryptic “TypeError:
> Cannot call method 'call' of undefined”.
>
> The upshot is that it does get better. Just hang in there.
>
> Good luck!
>
> Asim
>
>
> On Sun, Nov 9, 2014 at 11:07 AM, Glen Mailer <[email protected]> wrote:
>>
>> Hi Everyone,
>>
>> I'm new to ClojureScript, but I've been doing Clojure for a while, and
>> this was something that's been catching me out a lot.
>>
>> In Clojure, attempts to use an undefined var result in a compiler error,
>> whereas in CLJS they are left to fail at runtime. Presumably this is to play
>> nicely with the more dynamic JavaScript environment.
>>
>> However, because function calls expand to
>>
>> namespace.whatever.func.call(null, //...
>>
>> Then if i've typoed my function call or mixed something up somewhere, I
>> get the rather cryptic
>>
>> TypeError: Cannot call method 'call' of undefined
>>
>>
>> I'm finding this is especially awkward if i'm passing functions around or
>> there's a few invocations on the same line, and it's not obvious which one
>> of the function calls is actually the bad one.
>>
>>
>>
>> Is this something that happens less once you get used to ClojureScript?
>> Are there some tricks I can do to avoid making these mistakes?
>> Would it be possible to tweak the compiler to warn about undefined "var"
>> usage?
>> If compile-time warnings are too restrictive, would it be possible to have
>> a compilation mode where i get something like
>> safeCall(namespace.whatever.func, "namespace.whatever.func", // ....
>> which can tell me what the invocation looked like that failed?
>>
>>
>>
>> I hope that makes sense!
>>
>> Cheers
>> Glen
>>
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>
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