237d825dae
Summary:
In an effort to make debugging easier, add utilities that help pretty-print generators and effects with all the important fields (and none of the internal ones that you see in a debugger). Depth of recursion of printer is customizable.
Currently doesn't pass Flow because I have a helper function that takes an Object and returns an Object. Not sure how to make that type more specific.
Open to feedback on ways to change the output to be more readable/useful.
Output looks like this for a simple set of effects:
```
{
result: [ReturnCompletion value [Abstract 1735003607742184]],
generator: {
_entries: {
index: 39,
declared: [Abstract 1735003607742184],
args: []
},
id: 35,
_name: evaluateNodeForEffects,
pathConditions: [[Abstract 1735003607742177], [Abstract 1735003607742183]]
},
canBeApplied: true,
_id: 33
}
```
Pull Request resolved: https://github.com/facebook/prepack/pull/2270
Differential Revision: D8896030
Pulled By: cblappert
fbshipit-source-id: 4f15a047b43d41ccad53222850fad2bf3216b08c
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||
|---|---|---|
| .circleci | ||
| assets | ||
| bin | ||
| fb-www | ||
| flow-libs | ||
| flow-typed/npm | ||
| scripts | ||
| src | ||
| test | ||
| website | ||
| .eslintignore | ||
| .eslintrc | ||
| .flowconfig | ||
| .gitignore | ||
| .gitmodules | ||
| .prettierrc | ||
| .watchmanconfig | ||
| babel.config.js | ||
| 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
Plugins to other tools
The following are a few plugins to other tools. They have been created and are maintained separately from Prepack itself. If you run into any issues with those plugins, please ask the plugin maintainers for support.
- A Rollup plugin for Prepack
- A Webpack plugin for Prepack
- A Parcel plugin for Prepack
- A Visual Studio code plugin for Prepack
- A babel plugin which transforms Flow annotations into prepack model declarations.
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-cli
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 website directory 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:
- Build prepack into the website:
yarn build && mv prepack.min.js website/js - Run
python -m SimpleHTTPServer(Python 2) orpython -m http.server(Python 3) from thewebsite/directory
How to contribute
To read more about the project, check out this suggested reading wiki
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.