tsc should give an error if "typings" in package.json is not a string

[DanielRosenwasser]

Courtesy of a long troubleshooting session with @kataras on September 16, 2015.

If you have "typings" in package.json as an array or something instead of a string, we will crash hard:

C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:483
if (path.charCodeAt(0) === 47) {
^
TypeError: path.charCodeAt is not a function
at getRootLength (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:483:18)
at Object.combinePaths (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:643:13)
at loadNodeModuleFromDirectory (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29439:73)
at loadModuleFromNodeModules (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29462:26)
at nodeModuleNameResolver (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29405:20)
at resolveModuleName (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29385:28)
at C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29636:115
at Object.map (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:155:29)
at resolveModuleNamesWorker (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:29636:67)
at processImportedModules (C:\Users\Makis-PC\AppData\Roaming\npm\node_modules\typescript\lib\tsc.js:30013:35)

[mhegazy]

PRs are welcomed.

[mhegazy]

thanks @pimterry!

[DanielRosenwasser]

I don't think this was the correct fix. We silently do the wrong thing. We should be giving an error message.

[vladima]

one aspect that will be added in this PR is ability to trace module resolution process so we can record the fact that type of typings is incorrect. Raising errors at this point is bit complicated because currently resolvers simply don't have this ability and it will require changes on the managed side to add it (since module resolution happens on the preprocess step where we don't have the way to report errors and propagate them back).

[mhegazy]

@vladima has another validation tool that we should publish, the tool is geared towards package authors, this is where we should report the error.