Merge exisiting package.json to package.json created by emberoider build

[SparshithNR]

This uses the same logic from #178. I have reversed the order in which merging is done.
In #178 We merged new package.json content with old package.json content. That's why rebuild failed. If we just reverse the input values to the merge call it will fix the issue.

[ef4]

This is still the wrong place to do this. It allows a data cycle. Each time the build runs, we read and write from the same file. So future builds get state mixed in from earlier builds.

This is the right location to write, but the reading of package.json needs to come earlier, before it gets written out into this location.

The package.json from fastboot is present in one of the inputPaths, and the AppDiffer is what's copying it into this directory.

[SparshithNR]

but the reading of package.json needs to come earlier, before it gets written out into this location.

@ef4 I am not clear about this. Is there any recommendation where it can be done?

[ef4]

This build method has inputPaths as an argument. For each path in inputPaths, look for a package.json file in that path. If it exists, load it. Merge together all the ones you find. Finally, merge on top of that this.app.packageJSON as before, and write out to pkgPath.

[SparshithNR]

@ef4 I have updated the review with merging all package.json into one package.json file.

[ef4]

Thanks, this is closer now, but it's still reading from the output directory. It shouldn't be doing that.

Right now, the code

1. Does merging of all addon-provided package.json in gatherAssets.
2. Synthesizes a new assets from all of those which will get written to disk.
3. Reads back in its own asset from the output directory, to merge more things into it and write it out again.

Instead, it should stop doing all the asset merging, and directly in build() it should call code that locates all package.jsonfiles ininputPaths`, merges them in memory, merges the app's own package.json (also still in memory), and writes out the file once.

[ef4]

This is still reading from the output directory.

[ef4]

^ That was just a rebase on master before I make a few small changes. Overall this is pretty close.

[ef4]

Thanks. There were just a few small things needed:

• using require for the package.json is likely to run afoul of node's require cache. Any rebuild changes that cause the package.json to change might not get picked up. So I used readJSONSync from fs-extra instead.
• the assets:any type was too general, and was masking a bug. Assets are of multiple possible kinds, which needed to be handled.
• I added regression test coverage.