# jsvu [![Build status](https://travis-ci.org/GoogleChromeLabs/jsvu.svg?branch=master)](https://travis-ci.org/GoogleChromeLabs/jsvu) _jsvu_ is the JavaScript (engine) Version Updater. _jsvu_ makes it easy to install recent versions of various JavaScript engines without having to compile them from source. [![](screenshot.svg)](https://asciinema.org/a/rfS1M5ynKm1hGaBqJYJj0mGCi) ## Installation **Note:** _jsvu_ requires Node.js v10+. (_jsvu_ follows the latest [active LTS](https://github.com/nodejs/Release#release-schedule) version of Node.) Install the _jsvu_ CLI: ```sh npm install jsvu -g ``` Modify your dotfiles (e.g. `~/.bashrc`) to add `~/.jsvu` to your `PATH`: ```sh export PATH="${HOME}/.jsvu:${PATH}" ``` Then, run `jsvu`: ```sh jsvu ``` On first run, `jsvu` prompts you for your operating system and architecture, and the list of JavaScript engines you wish to manage through `jsvu`. It then downloads and installs the latest version of each of the engines you selected. To update the installed JavaScript engines later on, just run `jsvu` again. ## Supported engines per OS | JavaScript engine | Binary name | `mac64` | `win32` | `win64` | `linux32` | `linux64` | | ------------------------- | ------------------------- | ------------------ | ------- | ------------------ | --------- | --------- | | [**Chakra**][ch] | `chakra` or `ch` | ✅ | ✅ | ✅ | ❌ | ✅ | | [**GraalJS**][graaljs] | `graaljs` | ✅ | ❌ | ✅ | ❌ | ✅ | | [**Hermes**][hermes] | `hermes` & `hermes-repl` | ✅ | ❌ | ✅ | ❌ | ✅ | | [**JavaScriptCore**][jsc] | `javascriptcore` or `jsc` | ✅ | ❌ | ✅ \* | ❌ | ✅ | | [**QuickJS**][quickjs] | `quickjs` | ❌ | ✅ | ✅ | ✅ | ✅ | | [**SpiderMonkey**][sm] | `spidermonkey` or `sm` | ✅ | ✅ | ✅ | ✅ | ✅ | | [**V8**][v8] | `v8` | ✅ | ✅ | ✅ | ✅ | ✅ | | [**V8 debug**][v8] | `v8-debug` | ✅ | ✅ | ✅ | ✅ | ✅ | | [**XS**][xs] | `xs` | ✅ (32) | ✅ | ✅ (32) | ✅ | ✅ | \* JavaScriptCore requires external dependencies to run on Windows: - On 32-bit Windows, install [iTunes](https://www.apple.com/itunes/download/). - On 64-bit Windows, download the latest [WinCairoRequirements](https://github.com/WebKitForWindows/WinCairoRequirements/releases) and add its `bin64` directory to your `PATH`. [ch]: https://github.com/Microsoft/ChakraCore/issues/2278#issuecomment-277301120 [graaljs]: https://github.com/oracle/graaljs [hermes]: https://github.com/facebook/hermes/issues/17 [jsc]: https://bugs.webkit.org/show_bug.cgi?id=179945 [quickjs]: https://github.com/GoogleChromeLabs/jsvu/issues/73 [sm]: https://bugzilla.mozilla.org/show_bug.cgi?id=1336514 [v8]: https://bugs.chromium.org/p/chromium/issues/detail?id=936383 [xs]: https://github.com/Moddable-OpenSource/moddable-xst ## Integration with `eshost-cli` [`eshost-cli`](https://github.com/bterlson/eshost-cli) makes it easy to run and compare code in all JavaScript engines that `jsvu` installs. First, install `eshost-cli`: ```sh npm install -g eshost-cli ``` Then, either automatically configure `jsvu`-installed hosts: ```sh eshost --configure-jsvu ``` …or tell `eshost-cli` where `jsvu` installs each JavaScript engine following the instructions below. ### Linux/Mac ```sh eshost --add 'Chakra' ch ~/.jsvu/chakra eshost --add 'GraalJS' graaljs ~/.jsvu/graaljs eshost --add 'JavaScriptCore' jsc ~/.jsvu/javascriptcore eshost --add 'QuickJS' qjs ~/.jsvu/quickjs eshost --add 'SpiderMonkey' jsshell ~/.jsvu/spidermonkey eshost --add 'V8 --harmony' d8 ~/.jsvu/v8 --args '--harmony' eshost --add 'V8' d8 ~/.jsvu/v8 eshost --add 'XS' xs ~/.jsvu/xs ``` ### Windows ```bat eshost --add "Chakra" ch "%USERPROFILE%\.jsvu\chakra.cmd" eshost --add "GraalJS" graaljs "%USERPROFILE%\.jsvu\graaljs.cmd" eshost --add "JavaScriptCore" jsc "%USERPROFILE%\.jsvu\javascriptcore.cmd" eshost --add "SpiderMonkey" jsshell "%USERPROFILE%\.jsvu\spidermonkey.cmd" eshost --add "V8 --harmony" d8 "%USERPROFILE%\.jsvu\v8.cmd" --args "--harmony" eshost --add "V8" d8 "%USERPROFILE%\.jsvu\v8.cmd" eshost --add "XS" xs "%USERPROFILE%\.jsvu\xs.cmd" ``` That’s it! You can now run code snippets in all those engines with a single command: ```sh eshost -e 'new RegExp("\n").toString()' # https://crbug.com/v8/1982 eshost -e '(function maxCallStackSize() { try { return 1 + maxCallStackSize(); } catch (_) { return 1; }}())' eshost -e 'Date.parse("1 Octopus 2018")' ``` ## Integration with non-interactive environments On your personal devices, the only command you’ll ever need is `jsvu` as described above. There are no command-line flags to remember. 👋🏻 However, there are use cases for running jsvu within non-interactive environments (e.g. as part of continuous integration), where it’s desirable to bypass the initial `jsvu` prompt asking to confirm your operating system, architecture, and the list of JavaScript engines to install. Here’s how to do that: ```sh jsvu --os=linux64 --engines=all # Equivalent to: jsvu --os=linux64 --engines=chakra,graaljs,hermes,javascriptcore,quickjs,spidermonkey,v8,xs ``` If the operating system and architecture are not known in advance, the `--os=default` flag attempts to guess the correct value from the running environment. This might not be right for example if running a 32-bit Node.js process on a 64-bit machine. Note that `--engines=all` does not install the `v8-debug` binaries. ## Installing specific versions jsvu also supports installing specific versions alongside the main engine binaries (which it keeps up to date). Here’s an example: ```sh jsvu v8@7.2.502 ``` Binaries installed using this method are named `${BINARY}-${VERSION}`, so that the above example installs a binary named `v8-7.2.502`. This way, there’s never any conflict with the main `v8` binary, which jsvu can keep up to date. This feature works for all the supported engines: ```sh jsvu chakra@1.11.6 jsvu graaljs@20.2.0 jsvu hermes@0.6.0 jsvu javascriptcore@242640 jsvu quickjs@2019-08-18 jsvu spidermonkey@66.0b13 jsvu v8@7.2.502 jsvu v8-debug@7.1.302 jsvu xs@8.7.0 ``` If you pass in an invalid version number, or if the JavaScript engine creators don’t provide a precompiled binary for that specific version, jsvu shows an error. As a shorthand, for `v8` and `v8-debug` builds, jsvu can even figure out the last known good revision within a [milestone](https://v8.dev/docs/version-numbers). To install the latest available V8 v7.2.x for example, run: ```sh jsvu v8@7.2 # jsvu figures out that this means v7.2.502, and then installs that version. ``` ## Security considerations _jsvu_ avoids the need for `sudo` privileges by installing everything in `~/.jsvu` rather than, say, `/usr/bin`. _jsvu_ downloads files over HTTPS, and only uses URLs that are controlled by the creators of the JavaScript engine or, in the case of JavaScriptCore on Linux, the port maintainers. ## Author [Mathias Bynens](https://mathiasbynens.be/) ([@mathias](https://twitter.com/mathias))