Typescript

[hansmbakker]

I started working on typescript definitions for iotivity-node.
The strong typing prevents mistakes and assists during programming with intellisense in VS Code.

This is a work in progress, because I'm basically reverse engineering the JavaScript which is not always clear (e.g. objects are extended in several places with lodash, so that you don't have a clear overview of an object's properties, sometimes the return types of methods are not clear).

I yet have to start the lowlevel typings.

I could use some help and feedback from somebody who has more experience with programming for iotivity-node. Also I'm interested in hearing the rationale behind the code style (lots of lodash use and code nesting).

Is there anybody who would like to give me feedback or help a hand?

[zolkis]

Actually this is something we've been thinking about, and will consider adding TypeScript definitions to the spec. I hope to update on this during the coming days.

For time being, we can use an issue in this repo to discuss unclear things. So please check the spec, and point out where should it be more clear.

[coveralls]

Coverage remained the same at 87.083% when pulling e1c08f1 on wind-rider:typings into ab0e6f3 on otcshare:master.

[hansmbakker]

@zolkis thank you for linking to that spec, it helps a lot! I didn't know that iotivity-node was an implementation of that spec so it serves as good documentation!

I found out that the spec seems not to be followed wrt. the Error types - the spec uses Error subclasses (https://github.com/01org/iot-js-api/tree/master/api/ocf#error-handling) while iotivity-node uses the Error base class for everything, I'll make an issue for that

[coveralls]

Coverage remained the same at 87.083% when pulling 82624cd on wind-rider:typings into ab0e6f3 on otcshare:master.

[coveralls]

Coverage remained the same at 87.083% when pulling 9c4f92b on wind-rider:typings into ab0e6f3 on otcshare:master.

[coveralls]

Coverage remained the same at 87.083% when pulling 9c4f92b on wind-rider:typings into ab0e6f3 on otcshare:master.

[coveralls]

Coverage remained the same at 87.083% when pulling 2231e0c on wind-rider:typings into a4c1fd3 on otcshare:master.

[coveralls]

Coverage remained the same at 87.083% when pulling 2231e0c on wind-rider:typings into a4c1fd3 on otcshare:master.

[hansmbakker]

@zolkis, @gabrielschulhof do you have any feedback?

[zolkis]

Give it some more time, ELC is ongoing :)

[hansmbakker]

Sorry, I didn't know that

[gabrielschulhof]

@Wind-rider Sorry about the delay!

The change looks good overall, however, I am concerned that it adds a lot of weight to the installed size of this package, because it pulls type definitions for all of lodash.

Would it be possible to create a new npm package which provides these definitions and depends on iotivity-node?

[hansmbakker]

@gabrielschulhof it is possible to add something to https://github.com/DefinitelyTyped/DefinitelyTyped/ but I don't know how the npm publishing process works then...

[gabrielschulhof]

@Wind-rider, I'm not sure that having a symbolic link (such as js/node_modules/iotivity-node/index.d.ts) is portable across platforms. Have you tested the TypeScript examples on Windows?

[hansmbakker]

@gabrielschulhof you're right, Windows doesn't understand the symbolic link. It was only in there to make the examples work, but I see I moved the ts examples to a separate folder so it's not needed there anymore.

As for whether the examples work on windows - they are not platform-dependent; Typescript itself is not platform dependent. I'm having installation issues with iotivity-node on Windows (line ending issue probably; annoying...) so I couldn't test running them.

There is are two issues left in the high-level-resource-creation-server code - Promise.then(...) seems to expect a promise-like parameter but there are () => void style functions used on lines 43 and 50, which makes the compiler complain.

[hansmbakker]

Is there any feedback or thoughts on this?

[gabrielschulhof]

@Wind-rider just so you know, I'm still considering merging this PR, however, it may need to be updated because we're likely going to do a revamp of the high-level API to reflect the changes in the spec.

It would also be nice if you could add a test to make sure that the declarations are in sync with the actual API. That way you'd force a build failure every time we update the API, and we'd remember to also change the declarations ;)

[gabrielschulhof]

@Wind-rider I guess, depending on the timing of the implementation of the API change, this PR could land first, and then the API change would also involve the .ts files.

[hansmbakker]

it also depends on the choice of whether to have iotivity-node written in typescript that compiles to js + typings, or whether to have it as js + manual typings.

Technically, having it written in typescript would be the most elegant solution (no need to keep typings in sync, cleaner code in the library)

[hansmbakker]

@gabrielschulhof quite some time has passed, how is the new api coming along? Have you been able to take a look into TypeScript?

[gabrielschulhof]

@Wind-rider got distracted with security and API revamps, and other projects. I'll take another look ASAP. Thanks for sticking with it!