ts-macros
ts-macros is a typescript transformer which allows you to create function macros that expand to javascript code during the transpilation phase of your program.
📖 Documentation 🎮 Playground ✍️ Examples
The Basics
All macro names must start with a dollar sign ($
) and must be declared using the function keyword. Macros can then be called just like a normal function, but with a !
after it's name: $macro!(params)
. All the code inside of the macro is going to "expand" where the macro is called.
What you can do with ts-macros:
- Generate repetitive code
- Generate code conditionally, based on enviourment variables or other configuration files
- Generate types which you can use in your code (read more here)
- Create abstractions without the runtime cost
Usage
npm i --save-dev ts-macros
npm i --save-dev ts-patch
and add the ts-macros transformer to your tsconfig.json:
json
"compilerOptions": {
//... other options
"plugins": [
{ "transform": "ts-macros" }
]
}
Afterwards you can either:
- Transpile your code using the tspc
command that ts-patch provides.
- Patch the instance of typescript that's in your node_modules
folder with the ts-patch install
command and then use the tsc
command to transpile your code.
js
const TsMacros = require("ts-macros").default;
options: {
getCustomTransformers: program => {
before: [TsMacros(program)]
}
}
tsconfig.json
:
npm i --save-dev ts-node
json
"ts-node": {
"compiler": "ts-patch/compiler"
},
"compilerOptions": {
"plugins": [
{ "transform": "ts-macros" }
]
}
Security
This library has 2 built-in macros ($raw
and $comptime
) which execute arbitrary code during transpile time. The code is not sandboxed in any way and has access to your file system and all node modules.
If you're transpiling an untrusted codebase which uses this library, make sure to set the noComptime
option to true
. Enabling it will replace all calls to these macros with null
without executing the code inside them. It's always best to review all call sites to $$raw
and $$comptime
yourself before transpiling any untrusted codebases.
ttypescript/ts-patch:
"plugins": [
{ "transform": "ts-macros", "noComptime": true }
]
manually creating the factory:
TsMacros(program, { noComptime: true });
Contributing
ts-macros
is being maintained by a single person. Contributions are welcome and appreciated. Feel free to open an issue or create a pull request at https://github.com/GoogleFeud/ts-macros.