CHOMP

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'JS Make' - parallel task runner for the frontend ecosystem with a JS extension system.

Install

Make sure you have Cargo installed, then run:

cargo install chompbuild

Documentation

Getting Started

Migrating from npm Scripts

To convert an existing project using npm "scripts" to Chomp, run:

sh $ chomp --init --import-scripts √ chompfile.toml created with 2 package.json script tasks imported.

or the shorter version:

sh $ chomp -Ii √ chompfile.toml created with 2 package.json script tasks imported.

Then use chomp <name> instead of npm run <name>, and enjoy the new features of task dependence, incremental builds and parallelism!

Hello World

chomp works against a chompfile.toml TOML configuration in the same directory as the chomp command is run.

For example:

chompfile.toml ```toml version = 0.1

[[task]] target = 'name.txt' run = ''' echo "No name.txt, writing one." echo "World" > name.txt '''

[[task]] name = 'hello' target = 'hello.txt' dep = 'name.txt' run = ''' echo "Hello $(cat name.txt)" > hello.txt ''' ```

with this file saved, running:

```sh $ chomp hello

🞂 name.txt No name.txt, writing one. √ name.txt [4.4739ms] 🞂 hello.txt √ hello.txt [5.8352ms]

$ cat hello.txt Hello World ```

will populate the hello.txt file.

Subsequent runs, will see that the target is defined, and skip running the command again:

```sh chomp hello

● name.txt [cached] ● hello.txt [cached] ```

Changing name.txt to use a different name will invalidate the hello.txt target only:

```sh $ echo "Chomp" > name.txt $ chomp hello

● name.txt [cached] hello.txt invalidated by name.txt 🞂 hello.txt √ hello.txt [5.7243ms]

$ cat hello.txt Hello Chomp ```

Array deps can be defined for targets, whose targets will then be run first with invalidation based on target / deps mtime comparisons per the standard Makefile approach.

In Windows, Powershell is used and Bash on posix systems. Since both echo and > are defined on both systems the above works cross-platform (Powershell is automatically put into UTF-8 mode for > to work similarly).

Note that && and || are not supported in Powershell, so multiline scripts and ; are preferred instead.

Alternatively use engine = 'node' or engine = 'deno' to write JavaScript in the run function instead:

chompfile.toml ```toml version = 0.1

[[task]] target = 'name.txt' engine = 'node' run = ''' import { writeFileSync } from 'fs'; console.log("No name.txt, writing one."); writeFileSync(process.env.TARGET, 'World'); '''

[[task]] name = 'hello' target = 'hello.txt' deps = ['name.txt'] engine = 'node' run = ''' import { readFileSync, writeFileSync } from 'fs'; const name = readFileSync(process.env.DEP, 'utf8').trim(); writeFileSync(process.env.TARGET, Hello ${name}); ''' ```

Tasks are run with full parallelism permitted by the task graph, which can be controlled via the -j flag to limit the number of simultaneous executions.

Using the --watch flag watches all dependencies and applies incremental rebuilds over invalidations only.

Or using chomp hello --serve runs a static file server with watched rebuilds.

Extensions

Extensions are able to register task templates for use in Chompfiles.

Extensions are loaded using the extensions list, which can be any local or remote JS file:

toml version = 0.1 extensions = [ "./local.js", "https://remote.com/extension.js" ]

A core extensions library is provided with useful templates for the JS ecosystem, with the short protocol chomp:ext, a shorthand for the @chompbuild/extensions package contents.

A simple example is included below.

See the @chompbuild/extensions package for extension descriptions and examples.

Example: TypeScript with SWC

To compile TypeScript with the SWC template:

```toml version = 0.1 extensions = ['chomp@0.1:swc']

Automatically install SWC if not present

[template-options.npm] auto-install = true

[[task]] name = 'build:typescript' template = 'swc' target = 'lib/#.js' deps = ['src/#.ts'] ```

In the above, all src/**/*.ts files will be globbed, have SWC run on them, and output into lib/[file].js along with their source maps.

Only files not existing or whose src mtimes are invalidated (or SWC itself is updated) will be rebuilt.

Specific files or patterns can be built directly by name as well, skipping all other build work:

```sh chomp lib/main.js lib/dep.js

🞂 lib/dep.js 🞂 lib/app.js √ lib/dep.js [317.2838ms] √ lib/app.js [310.0831ms] ```

Patterns are also supported for building tasks by name or filename (the below two commands are equivalent):

sh $ chomp lib/*.js $ chomp :build:*

To remove the template magic, run chomp --eject to convert the chompfile.toml into its untemplated form:

```sh $ chomp --eject

√ chompflie.toml template tasks ejected ```

Resulting in the updated chompfile.toml:

```toml version = 0.1

[[task]] name = 'build:typescript' target = 'lib/#.js' dep = 'src/#.ts' stdio = 'stderr-only' run = 'node ./node_modules/@swc/cli/bin/swc.js $DEP -o $TARGET --no-swcrc --source-maps -C jsc.parser.syntax=typescript -C jsc.parser.importAssertions=true -C jsc.parser.topLevelAwait=true -C jsc.parser.importMeta=true -C jsc.parser.privateMethod=true -C jsc.parser.dynamicImport=true -C jsc.target=es2016 -C jsc.experimental.keepImportAssertions=true' ```

License

GPLv3

For licensing discussion, see https://github.com/guybedford/chomp/issues/62.