There's very little consistency when it comes to checking params in plugin code.
globalization.js<https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-js.git;a=blob;f=lib/common/plugin/globalization.js;h=a57062ce8b1e0cc95dde54f8ca600f6ee4876bfd;hb=HEAD>: checks every args. logs errors and returns without calling errback, does not allow missing errCB. resolveLocalFileSystemURI.js<https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-js.git;a=blob;f=lib/common/plugin/resolveLocalFileSystemURI.js;h=c83b0aac3704c46782c3e19876afb180c32fc081;hb=HEAD>: Allows missing successCB and errCB. Sanity checks URL has a colon in it. notification.js<https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-js.git;a=blob;f=lib/common/plugin/notification.js;h=fbf9046a0e03bb6647219d7201b23f26f4d47084;hb=HEAD>: doesn't check types at all contacts.js<https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-js.git;a=blob;f=lib/common/plugin/contacts.js;h=2f5a51a20c8ad14b96c4ef935a28686a9bd87eca;hb=HEAD>: Throws TypeError if missing successCB, allows missing errCB compass.js<https://git-wip-us.apache.org/repos/asf?p=incubator-cordova-js.git;a=blob;f=lib/common/plugin/compass.js;h=c97c1588bf69d2c94cde64736345a7d8b1dc32fe;hb=HEAD>: Logs and returns if callbacks are of wrong type. success required, error optional. So, the things to agree upon are: 1. Should we check types or not? 2. Success / error callbacks : optional or not? 3. When type errors happen, log & return, call errBack, or throw TypeError? For some extra inspiration, I played around with what it would look like to at least factor out type checking code. Have a look at the module<https://github.com/agrieve/incubator-cordova-js/blob/argscheck/lib/common/argscheck.js>and it's tests<https://github.com/agrieve/incubator-cordova-js/blob/argscheck/test/test.argscheck.js>. Also, here's<https://github.com/agrieve/incubator-cordova-js/blob/argscheck/lib/common/plugin/globalization.js>what it looks like being used in globalization.js. Now, here's my thoughts for the three questions 1. Should we check types or not? - I think it is useful since incorrect args end up in exec() calls and are therefore harder to debug when they are wrong. - Perhaps instead of checking types, we add a helper for coercing types? This may only apply to strings / numbers though... - I also kind of like the idea of being able to turn off type checking for release mode. Having a common function to do the type checking would allow us to turn checking on/off for performance. 2. Success / error callbacks : optional or not? - I'm not positive we need to make these all consistent - If anything, I'd say we'd want them to be optional. 3. When type errors happen, log & return, call errBack, or throw TypeError? - TypeError is my preference here. This matches what browser APIs do when it doesn't like params.
