f3355c91ca
Summary: Release note: Adds support for folding simple React class components This PR adds the concept of "simple" class components. A "simple" class component is defined as: - having only a "render" method or many method, i.e. `render()`, `_renderHeader()`, `_renderFooter()` - having no lifecycle events - having no state - having no instance variables The only things a class component should be able to access on "this" are: - `this.props` - `this.context` - `this._someRenderMethodX()` etc It does this by first attempting to evaluate any class component with the heuristics as if it were a simple class component. If that throws an error (entirely expected for most class components), it catches the error and falls back to trying to use the "complex" class component route for evaluation instead. Furthermore, I've added "transforms". This allows post-transforms of the serialized AST for additional functions. The simple class component adds a transform to convert AST nodes of `this.props` to `props` and `this.context` to `context` respectfully – whilst adding arguments to the function; something that is necessary to convert simple class component render methods to functional components. This PR also adds logic to squash simple class components into functional components at the root (as simple class components are easily convertible to functional components). Closes https://github.com/facebook/prepack/pull/1204 Differential Revision: D6485508 Pulled By: trueadm fbshipit-source-id: 06ebeebad5d23c0677a0e3f0cb8dd23c45735429 |
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| flow-typed/npm | ||
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| test | ||
| .babelrc | ||
| .eslintignore | ||
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| .flowconfig | ||
| .gitignore | ||
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| .watchmanconfig | ||
| circle.yml | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| package.json | ||
| PATENTS | ||
| README.md | ||
| webpack.config.js | ||
| yarn.lock | ||
Prepack 
Prepack is a partial evaluator for JavaScript. Prepack rewrites a JavaScript bundle, resulting in JavaScript code that executes more efficiently. For initialization-heavy code, Prepack works best in an environment where JavaScript parsing is effectively cached.
See the official prepack.io website for an introduction and an interactive REPL playground.
How to use Prepack
Install the CLI via npm,
$ npm install -g prepack
Or if you prefer yarn, make sure you get yarn first,
$ npm install -g yarn
and then install the Prepack CLI via yarn:
$ yarn global add prepack
You may need to prepend (pun intended!) the command with sudo in some cases.
Let the party begin
To compile a file and print the output to the console:
$ prepack script.js
If you want to compile a file and output to another file:
$ prepack script.js --out script-processed.js
Detailed instructions and the API can be found at Prepack CLI: Getting Started
Status
- test262 status on master branch
- code coverage report for serialization tests
- To see the status for a pull request, look for the message All checks have passed or All checks have failed. Click on Show all checks, Details, Artifacts, and then test262-status.txt or coverage-report-sourcemapped/index.html.
How to get the code
- Clone repository and make it your current directory.
git submodule initgit submodule update --init- Get yarn and node, then do
yarn
Note: For development work you really need yarn, as many scripts require it.
How to build, lint, type check
- Get the code
yarn build
You can later runyarn watchin the background to just compile changed files on the fly.yarn lintyarn flow
How to run tests
- Get the code
- Make sure the code is built, either by running
yarn buildoryarn watch yarn test
You can run individual test suites as follows:
yarn test-serializer
This tests the interpreter and serializer. All tests should pass.yarn test-test262
This tests conformance against the test262 suite. Not all will pass, increasing conformance is work in progress.
How to run the interpreter
- Get the code
- Make sure the code is built, either by running
yarn buildoryarn watch yarn repl
This starts an interactive interpreter session.
How to run Prepack
-
Get the code
-
Make sure the code is built, either by running
yarn buildoryarn watch. -
Have a JavaScript file handy that you want to prepack, for example:
echo "function hello() { return 'hello'; } function world() { return 'world'; } s = hello() + ' ' + world();" >/tmp/sample.js -
cat /tmp/sample.js | yarn prepack
Try--helpfor more options.
How to validate changes
Instead of building, linting, type checking, testing separately, the following does everything together:
yarn validate
How to edit the website
The content for prepack.io resides in the gh-pages branch of this repository. To make changes, submit a pull request, just like for any code changes. In order to run the website locally at localhost:8000, run python -m SimpleHTTPServer (Python 2) or python -m http.server (Python 3) from the cloned gh-pages branch.
At this time, a particular bundled version of Prepack is checked in to the gh-pages branch at js/prepack.min.js. To update the bundle, run yarn build-bundle from the master branch, and copy the resulting prepack.min.js file into the gh-pages branch into the js directory, and submit a pull request for that change.
How to contribute
For more information about contributing pull requests and issues, see our Contribution Guidelines.
License
Prepack is BSD-licensed. We also provide an additional patent grant.