Summary:
There's quite a bit of code scattered around the packager regarding ignoring the `providesModule` Haste pragma in any file that isn't in `react-native`, `react-tools` or `parse`. There is even a (passing) test case.
However, there's an edge case.
Take, for example, `fbjs`. It has a module inside of it called `ErrorUtils`. `react-relay` requires this file normally, in Common.JS style, by doing `require('fbjs/libs/ErrorUtils')`. But when `react-native` attempts to require `ErrorUtils` using the HasteModule format (in it's JavaScript initialization), it resolves the `fbjs` `ErrorUtils` module, instead of RN's `ErrorUtils`.
This happens, it turns out, because when a module is read (in `Module._read`), it's not caring about whether or not it should pay attention to `providesModule`, and is just assigning the `providesModule` value as the id of the module no matter what. Then when `Module.getName` is called, it will always use that `data.id` that was set, thus creating the wrong dependency tree.
This
Closes https://github.com/facebook/react-native/pull/3625
Reviewed By: svcscm
Differential Revision: D2632317
Pulled By: vjeux
fb-gh-sync-id: efd8066eaf6f18fcf79698beab36cab90bf5cd6d
Summary:
The cache is only used for JSTransformer at the moment. We're doing IO and some computation to get each module's name, whether is a haste or node module and it's dependencies. This work happens on startup so by caching this value we shouldbe able to reduce the start up time. Lets promote the Cache to the Packager level to be able to use it by any of the components of the packager. For now, on this diff we'll start using it to cache the mentioned fields.
Also we had to introduce the concept of fields in the cache as manually merging the date we had for each path is not possible as we're using promisses all around. With the new API, each field is a promise.
@amasad and I did some manual testing to measure the impact of this change and looks like it's saves 1 second when building the haste map (which represents 50% of the time). Overall this reduces 1 second of start up time which was currently about 8s on my mac book pro.
Summary:
@public
Fixes#773, #1055
The resolver was getting a bit unwieldy because a lot has changed since the initial writing (porting node-haste).
This also splits up a large complex file into the following:
* Makes use of classes: Module, AssetModule, Package, and AssetModule_DEPRECATED (`image!` modules)
* DependencyGraph is lazy for everything that isn't haste modules and packages (need to read ahead of time)
* Lazy makes it fast, easier to reason about, and easier to add new loaders
* Has a centralized filesystem wrapper: fast-fs (ffs)
* ffs is async and lazy for any read operation and sync for directory/file lookup which makes it fast
* we can easily drop in different adapters for ffs to be able to build up the tree: watchman, git ls-files, etc
* use es6 for classes and easier to read promise-based code
Follow up diffs will include:
* Using new types (Module, AssetModule etc) in the rest of the codebase (currently we convert to plain object which is a bit of a hack)
* using watchman to build up the fs
* some caching at the object creation level (we are recreating Modules and Packages many times, we can cache them)
* A plugin system for loaders (e.g. @tadeuzagallo wants to add a native module loader)
Test Plan:
* ./runJestTests.sh react-packager
* ./runJestTests.sh PackagerIntegration
* Export open source and run the e2e test
* reset cache
* ./fbrnios.sh run and click around
