ÀLaMode
ÀLaMode is a RegExp-based transpiler of source code in Node.JS that supports transpilation of import
and export
statements including source map for debugging, while keeping the original code pretty much the same (no interrop require). It also can transpile JSX (without source maps ATM and some minor limitations).
The package can be used via the CLI to build packages, or via the require hook to transform modules on-the-fly.
If you've tried it and are having trouble seeing unknown keyword export
, check if your issue falls under the category described in the troubleshooting. That's the single problem that we've seen after a year of using this software.
yarn add -D alamode
Why ÀLaMode
ÀLaMode is a neat, fast, low-weight alternative to AST-based transpilers. If you only want import
and export
statements, don't disrespect yourself by continuing to use Babel, and make a switch to ÀLaMode today. What am I talking about? Read next.
It's Neat
The source code is left pretty much intact, with line numbers preserved, and exports just being renamed to module.export
while making sure to export the default module first if it is present. There is no need to come up with super-fancy solutions and try to build a rocket when all you need is a remote control. That means, don't worry about EcmaScript modules standard, it's significance is blown out of proportions by the "community" who has nothing better to do. Just rename exports to module.exports and imports to require — that's the philosophy behind ÀLaMode.
Source Code | Transpiled Code |
---|
import Stream, {
Transform,
} from 'stream'
import { join } from 'path'
export default class S extends Transform {
constructor(path, parent) {
super()
this.source = join('example', path)
if (parent instanceof Stream)
this.pipe(parent)
}
}
export const c = (input = '') => {
return 'c' + input ? `-${input}` : ''
}
export const b = (times = 0) => {
return 'b' + times ? `-${times}` : ''
}
|
const Stream = require('stream'); const {
Transform,
} = Stream;
const { join } = require('path');
class S extends Transform {
constructor(path, parent) {
super()
this.source = join('example', path)
if (parent instanceof Stream)
this.pipe(parent)
}
}
const c = (input = '') => {
return 'c' + input ? `-${input}` : ''
}
const b = (times = 0) => {
return 'b' + times ? `-${times}` : ''
}
module.exports = S
module.exports.c = c
module.exports.b = b
|
Show Babel Output
"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.b = exports.c = exports.default = void 0;
var _stream = _interopRequireWildcard(require("stream"));
var _path = require("path");
function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) { var desc = Object.defineProperty && Object.getOwnPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : {}; if (desc.get || desc.set) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } } newObj.default = obj; return newObj; } }
class S extends _stream.Transform {
constructor(path, parent) {
super();
this.source = (0, _path.join)('example', path);
if (parent instanceof _stream.default) this.pipe(parent);
}
}
exports.default = S;
const c = (input = '') => {
return 'c' + input ? `-${input}` : '';
};
exports.c = c;
const b = (times = 0) => {
return 'b' + times ? `-${times}` : '';
};
exports.b = b;
It Has 0 Dependencies
ÀLaMode does not install any additional dependencies, and it has been optimised with Google Closure Compiler. That means you don't have to wait ages for each new real dependency in your project to link with Babel's bloatware you don't care about. Just focus on the work and enjoy the single new directory in your node_modules
.
ÀLaMode: 8 yarn.lock lines | Babel: 1650 yarn.lock Lines |
---|
|
|
It Respects JSDoc
Let's face it, Babel is software for masses that has capitalized on people's vulnerability in wanting to use import
and export
statements which is one of the best features on the language. You say let them be, I say look what they are doing to your documented code without caring a single bit:
ÀLaMode: Gold Standard | Babel: JSDoc Enemy |
---|
|
|
Original Source:
export const b = (times) => {
return 'b' + (times ? `-${times}` : '')
}
See if you can figure out why this happens. Unlike Babel, our Node.JS Development Company cares about quality and developer experience, so we're offering ÀLaMode as a simple and lightweight solution to transpile packages.
Table Of Contents
Installation
The software can be installed either as a global dependency, or as a project dependency.
Global
When installed globally, it will be used directly via a binary, such as alamode src -o build
.
Package Manager | Installation |
---|
npm | npm i -g alamode |
yarn | yarn add global alamode |
Project
When installed in a project, it will be used via the package.json
script, e.g., yarn build
or npm run build
.
// package.json
{
"name": "project",
"version": "1.0.0",
"description": "An example project",
"main": "build",
"scripts": {
"build": "alamode src -o build"
},
"files": ["build"],
"license": "MIT"
}
Package Manager | Installation |
---|
npm | npm i --save-dev alamode |
yarn | yarn add -DE alamode |
CLI
The binary accepts a path to a single file, or a directory with the source code as the first argument, and a path to the build folder via -o
argument.
alamode src -o build
There are other arguments which can be passed.
Argument | Short | Description |
---|
source | | The location of the input file or directory to transpile. |
--output | -o | The location of where to save the transpiled output. |
--version | -v | Show the version number. |
--help | -h | Display the usage information. |
--ignore | -i | Comma-separated list of files inside of source dir to
ignore, for example, bin,.eslintrc . |
--noSourceMaps | -s | Disable source maps. |
--extensions | -e | Files of what extensions to transpile. Default js,jsx . |
--jsx | -j | Enable JSX mode: only update JSX syntax to use hyperscript.
Does not transpile import/export statements. |
--module | -m | Works together with jsx to also transpile modules while
transpiling JSX. |
--preact | -p | When transpiling JSX, automatically insert at the top
import { h } from "preact" . |
--preact-externs | -E | Same as preact , but imports from @externs/preact
import { h } from "@externs/preact" . |
--debug | -d | Will make ÀLaMode stop after replacing markers. |
--require | -r | Renames require calls into imports, and module.exports assignments to exports.
Great for refactoring older code. |
Setting the NODE_DEBUG
environmental variable to alamode
will print the list of processed files to the stderr
.
$ NODE_DEBUG=alamode alamode src -o build -i bin/alamode.js
ALAMODE 97955: index.js
ALAMODE 97955: bin/catcher.js
ALAMODE 97955: bin/index.js
ALAMODE 97955: lib/index.js
--help
Shows all available commands.
A tool to transpile JavaScript packages using regular expressions.
Supports import/export and JSX transpilation.
https://artdecocode.com/alamode/
alamode source [-o destination] [-i dir,file] [-s] [-jp]
source The location of the input file or directory to transpile.
--output, -o The location of where to save the transpiled output.
--version, -v Show the version number.
--help, -h Display the usage information.
--ignore, -i Comma-separated list of files inside of `source` dir to
ignore, for example, `bin,.eslintrc`.
--noSourceMaps, -s Disable source maps.
--extensions, -e Files of what extensions to transpile.
Default: js,jsx.
--jsx, -j Enable JSX mode: only update JSX syntax to use hyperscript.
Does not transpile `import/export` statements.
--module, -m Works together with `jsx` to also transpile modules while
transpiling JSX.
--preact, -p When transpiling JSX, automatically insert at the top
`import { h } from "preact"`.
--preact-externs, -E Same as `preact`, but imports from `@externs/preact`
`import { h } from "@externs/preact"`.
--debug, -d Will make ÀLaMode stop after replacing markers.
--require, -r Renames `require` calls into imports, and `module.exports` assignments to exports.
Great for refactoring older code.
Example:
alamode src -o build
Compiling JSX: --jsx, --preact
ÀLaMode can transpile JSX syntax. In the jsx
mode, the import/export
statements will be left intact, but the source code will be transformed to add pragma invocations, such as h(Component, { props }, children)
. The default pragma is h
for Preact, and to avoid writing import { h } from 'preact'
in each file, the -p
option can be passed for ÀLaMode to add it automatically.
For example, the following file can be compiled:
import { render } from 'preact'
const Component = ({ test, ...props }) => (
<div id="example" {...props}>
{test}
</div>
)
render(<Component cool>Example</Component>, document.body)
Using the alamode example/index.jsx -j -p
command:
import { h } from 'preact'
import { render } from 'preact'
const Component = ({ test, ...props }) => (
h('div',{...props,'id':"example"},
test,
)
)
render( h(Component,{cool:true},`Example`), document.body)
CSS Injector
ÀLaMode can transpile the import './style.css'
directives into import './style.css.js'
, where style.css.js
becomes a module with a css-injector script that will add your CSS to the head
element.
ÀLaNode
To be able to spawn modules without having to create a proxy file as below:
require('alamode')()
require('./package')
ÀLaMode bundles a binary called alanode
. It will do the same thing as above, so that running modules with import
and export
statements becomes really easy.
$ alanode source
It changes import
and export
statements into require
calls and module.export
expressions. It also normalises process.argv
to hide its presence, so that programs can safely keep using the argv array without unexpected results.
With the following file that uses an import:
import { constants } from 'os'
console.log(process.argv)
console.log(constants.signals.SIGINT)
$ alanode t
will generate the result successfully:
[ '/Users/anton/.nvm/versions/node/v10.16.0/bin/node',
'/Users/anton/a-la/alamode/test/fixture/t' ]
2
ÀLaNode is also available as a standalone package alanode
.
.alamoderc.json
A transform can support options which are set in the .alamoderc.json
configuration file. The configuration file is read from the same directory where the program is executed (cwd). Options inside of the env
directive will be active only when the ALAMODE_ENV
environmental variable is set to the env
key.
{
"env": {
"test-build": {
"import": {
"replacement": {
"from": "^((../)+)src",
"to": "$1build"
}
}
}
},
"import": {
"alamodeModules": ["alamode", "example"],
"stdlib": {
"path": "stdlib.js",
"packages": ["example"]
}
}
}
Transforms
The main import and export transforms are included as part of ÀLaMode.
- 📥
@a-la/import
Changes imports to requires. Read Wiki for additional options and guidance on how to test builds and build source code to use the standard library compiled out of all dependencies using Depack. - 📤
@a-la/export
Updates export
to module.exports
while preserving whitespace for human-readable output.
Require Hook
The purpose of the require hook is to be able to transpile files automatically when they are imported.
To use this feature, alamode
needs to be required
in a separate file, after which the import
and export
statements will become available.
For example, take the following directory structure, with a main and library files:
example/require
├── debug.js
├── index.js
├── lib.js
├── multiple.js
└── require.js
index.js | lib.js |
---|
|
import getInfo from './lib'
console.log(getInfo())
|
import { platform, arch } from 'os'
export default () => {
return `${platform()}:${arch()}`
}
|
The require hook would work in the following way:
require('alamode')()
require('.')
By executing the node require.js
command, alamode
will be installed and it will do its job dynamically for every .js
file that is required, enabling to use import
and export
statements.
darwin:x64
_alamode.HookConfig
: The options for ÀLaMode Hook.
Name | Type | Description | Default |
---|
pragma | string | What pragma to add on top of JSX programs. Default const { h } = require('preact'); . | - |
noWarning | boolean | Disable warnings when resetting existing hooks. | false |
ignoreNodeModules | boolean | Auto-ignore node_modules. Independent of any matcher. | true |
matcher | (path: string) => boolean | The function that will be called with the path and return whether the file should be transpiled. | - |
Multiple Calls To Alamode()
When the call is made multiple times in the program, the latter calls will revert the previous hooks and install new ones. The warning will be shown unless the noWarning
option is set to true.
const alamode = require('alamode')
alamode()
const path = require('path')
const preact = path.relative('', path
.dirname(require.resolve('preact/package.json')))
alamode({
pragma: `const { h } = require("./${preact}");`,
})
Reverting JS hook to add new one.
Reverting JSX hook to add new one, pragma:
const { h } = require("./node_modules/preact");
This can happen when the tests are set up to run with Zoroaster with the -a
flag for alamode, and the source code also tries to install the require hook.
Source Maps
The source maps are supported by this package, but implemented in a hack-ish way. The transforms will aim to preserve line and column numbers, so that no additional remapping is required. However this is not enough to generate a source map good enough for a debugger -- it needs to know about mappings of positions between segments which can be operators, function calls, etc. alamode
simply breaks the source code into distinct chunks such as white-spaces, identifiers and comments, and down into individual symbols. Using this method, the size of a source map is larger, but it still works. In further versions, this will be improved to allow to extract real segments.
Click to View: debug session
Troubleshooting
Because there can be many intricacies when transpiling with regular expressions, problems might arise from time to time. If using the require
hook, the best solution is to build the source code using alamode
binary, and see where the error occurs. Then it must be analysed why it happens, for example:
- The
import
or export
transform does not match the case. - A portion of source code is cut out before the transform with
markers
so that the line does not participate in a transform.
So the single most common problem that we've experienced, is using the //
and /*
inside string literals (`
), e.g.,
const host = 'localhost'
const port = 9999
const url = `https://${host}:${port}`
export const test = 'hello world'
const otherUrl = `https://${host}:${port}`
example/trouble.js:5
export const test = 'hello world'
^^^^^^
SyntaxError: Unexpected token export
at Module._compile (internal/modules/cjs/loader.js:721:23)
at Module.p._compile (node_modules/alamode/compile/depack.js:49:18)
at Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Object.k.(anonymous function).y._extensions.(anonymous function) [as .js] (node_modules/alamode/compile/depack.js:51:7)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Module.require (internal/modules/cjs/loader.js:690:17)
at require (internal/modules/cjs/helpers.js:25:18)
at Object.<anonymous> (node_modules/documentary/build/fork.js:2:1)
This is because //${host}:${port}`
will be cut until the end of the line as a comment prior to the template, and the template will match until the next opening backtick rather than the correct one, taking out the export
from the transformation. To validate that, we can run the alamode src -d
command:
const host = %%_RESTREAM_STRINGS_REPLACEMENT_0_%%
const port = 9999
const url = %%_RESTREAM_LITERALS_REPLACEMENT_0_%%https:%%_RESTREAM_INLINECOMMENTS_REPLACEMENT_1_%%
Now to fix this issue, either use '
to concatenate strings that have /*
and //
, or use import { format } from 'url'
to dynamically create addresses.
Copyright