Summary:
The first time I tried to commit this changeset, it was causing many new packages to be installed, because the dependency would depend on newer versions that what we have installed. So, I had made a diff so upgrade all the babel packages. Unfortunately this caused some problem as the newer versions of Babel are more strict on some syntaxes. Of course, these have to be addressed, but I don't want this changeset to be coupled with Babel upgrades and the issues that arise from it.
So instead, I decided to install the slightly older version of the async-to-generator module. At first I tried with just doing:
yarn add babel-plugin-transform-async-to-generator@6.16.0
But, `yarn` is stubborn: because this module depends on a caret version of `babel-helper-remap-async-to-generator`, it installs the very last version of it, that itself needs more recent versions of other Babel modules. So, instead, I add to install a slightly older version of the dependency manually, then then the plugin:
yarn add babel-helper-remap-async-to-generator@6.16.0
yarn add babel-plugin-transform-async-to-generator@6.16.0
This allows us to have a `yarn.lock` with only a minimal amount of changes, and uncouple this change from any Babel upgrades. Because we only have a few new modules, the `node_modules` folder also stays the same, 133M, and it gives us confidence this will not cause significant startup time regressions.
Reviewed By: cpojer
Differential Revision: D4578733
fbshipit-source-id: deb0f720b895b7196aaf432adec3e56f18663940
Summary:
allow-large-files
By using async/await the code is (1) less nested, (2) more compact and (3) more robust (no exceptions running away, and much less risks of forgetting to call the callback/resolve, or mistakenly calling it twice). I now tend to think we could switch to it for all the callsites that are not in a perf-critical path.
I switched from 'request' to 'node-fetch' because 'request' has an annoying callback with 2 arguments. So it's simpler to use an interface that's (1) already returning a Promise and (2) that is becoming standard.
This changeset was a way for me to start experiment with introducing async/await in packager codebase, and it looks pretty good so far.
Reviewed By: cpojer
Differential Revision: D4559167
fbshipit-source-id: 89a328c5766c2ba890e9d0e67a81a38dac6cfc73
Jean Lauliac
cpojer