Add usePromise parameter to JS client

[delenius]

This adds a "usePromise" boolean parameter to the JS client generator (disabled by default).

Fixes #2014.
For some discussion on the benefits of using Promises, see http://bluebirdjs.com/docs/why-promises.html

Note: I have not added any unit tests for this feature, because it produces a different client API, so the existing PetStore tests will not work. I could add:

samples/client/javascript/test/api/PetApiPromiseTest.js
samples/client/javascript/test/api/ApiClientPromiseTest.js

and furthermore, modify bin/javascript-petstore.sh to produce a promise version of the test client.

Let me know if you want me to do that, or create tests in any other way.

In the meantime, consider this addition experimental. It does not impact existing functionality since it has to be explicitly enabled using --additional-properties usePromises=true

[wing328]

@delenius thanks for adding the support for Promises.

Instead of modifying bin/javascript-petstore.sh, I would suggest adding bin/javascript-promise-petstore.sh and output the JS client with promise in samples under samples/client/petstore/javascript-promise. Then you can add test cases in that directory.

If it's not too much work, I would suggest using CLI option (instead of --additional-properties) for usePromises

[delenius]

@wing328, can you point me to how to add a CLI option instead of --additional-properties, for a language-specific option? I don't want to pollute the generic set of options.

[delenius]

Tests added as discussed above, though some tests are not implemented:

1. Can not check values in the request object generated inside ApiClient, because it is not returned (a Promise is returned instead).
2. Can not check response headers, because they are not returned in the Promise version -- only the data is returned.

[wing328]

would this help #1851 ?

[delenius]

That looks like what I did, except that there is no io/swagger/codegen/options dir, where that OptionProvider goes. How is the parameter in that commit passed on the command line? Maybe the same style already works in my PR.

[wing328]

Sorry I missed the lines about adding USE_PROMISES to CLIOption.

[wing328]

Btw, I saw commits from others in the commit tabs. Is that due to git rebase master?

[delenius]

Oh, yeah I was confused by that too. Yes, probably. I was trying to integrate the latest master branch into my feature branch...

[wing328]

Instead of putting the default value in the description, you can use .defaultValue instead. Here is an example:

swagger-codegen/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/PerlClientCodegen.java

Line 79 in ee8547f

cliOptions.add(new CliOption(MODULE_NAME, "Perl module name (convention: CamelCase or Long::Module).").defaultValue("SwaggerClient"));

[wing328]

FYI. I usually rebase my branch (e.g. fix_something) as follows:

git checkout master
git pull upstream master 
git checkout fix_something
git rebase master

Assuming upstream is a remote defined as https://github.com/swagger-api/swagger-codegen.git

[delenius]

@wing328, yeah that's how I did my rebase too, except I think I did a git push (to origin, i.e. my fork), after git pull, which seems to have complicated things.

I fixed the defaultValue issue. Note that there are other default values in the same file that use the "manual" style. I didn't want to touch those though.

[wing328]

@delenius thanks for the update. We can clean those up later.

I also left you a comment about wildcard import.

[delenius]

I for sure did not change those imports (it's because other people's commits are listed with my PR for some reason). I agree on not using wildcards, and I typically use IDE auto-imports which does not generate wildcards. But I can try to fix them anyway.

[wing328]

Yes, you're right. @fehguy did that. No worry then.

I'll review your PR and approve shortly.

[delenius]

No worries, I already fixed the imports.

[wing328]

👍

[delenius]

@wing328, regarding the other people's commits showing up: Is it because I messed up my rebase somehow? Or does that always happen after a rebase? I'd like to not repeat the same mistake in the future.

[wing328]

It never happens to me when I perform a rebase. I've seen others doing that due to a bad rebase.

[wing328]

PR merged. Thanks again for the contribution 🍻