Loaders - BunDocumentation Index
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Skip to main contentBun home pageBuilt-in loaders for the Bun bundler and runtime
import my_toml from "./my_file" with { type: "toml" };
// or with dynamic imports
const { default: my_toml } = await import("./my_file", { with: { type: "toml" } });
Built-in loaders
js
JavaScript loader. Default for .cjs and .mjs.
Parses the code and applies a set of default transforms like dead-code elimination and tree shaking. Note that Bun does not attempt to down-convert syntax at the moment.
jsx
JavaScript + JSX loader. Default for .js and .jsx.
Same as the js loader, but JSX syntax is supported. By default, JSX is down-converted to plain JavaScript; the details of how this is done depends on the jsx* compiler options in your tsconfig.json. Refer to the TypeScript documentation on JSX for more information.
ts
TypeScript loader. Default for .ts, .mts, and .cts.
Strips out all TypeScript syntax, then behaves identically to the js loader. Bun does not perform typechecking.
tsx
TypeScript + JSX loader. Default for .tsx.
Transpiles both TypeScript and JSX to vanilla JavaScript.
json
JSON loader. Default for .json.
JSON files can be directly imported.
import pkg from "./package.json"; pkg.name; // => "my-package"During bundling, the parsed JSON is inlined into the bundle as a JavaScript object.
const pkg = {
name: "my-package",
// ... other fields
};
pkg.name;
If a .json file is passed as an entrypoint to the bundler, it will be converted to a .js module that export defaults the parsed object.
InputOutput{
"name": "John Doe",
"age": 35,
"email": "johndoe@example.com"
}
jsonc
JSON with Comments loader. Default for .jsonc.
JSONC (JSON with Comments) files can be directly imported. Bun will parse them, stripping out comments and trailing commas.
import config from "./config.jsonc"; console.log(config);During bundling, the parsed JSONC is inlined into the bundle as a JavaScript object, identical to the json loader.
var config = {
option: "value",
};
import config from "./bunfig.toml";
config.logLevel; // => "debug"
// via import attribute:
// import myCustomTOML from './my.config' with {type: "toml"};
During bundling, the parsed TOML is inlined into the bundle as a JavaScript object.
var config = {
logLevel: "debug",
// ...other fields
};
config.logLevel;
If a .toml file is passed as an entrypoint, it will be converted to a .js module that export defaults the parsed object.
InputOutputname = "John Doe" age = 35 email = "johndoe@example.com"yaml YAML loader. Default for .yaml and .yml. YAML files can be directly imported. Bun will parse them with its fast native YAML parser.
import config from "./config.yaml";
console.log(config);
// via import attribute:
import data from "./data.txt" with { type: "yaml" };
During bundling, the parsed YAML is inlined into the bundle as a JavaScript object.
var config = {
name: "my-app",
version: "1.0.0",
// ...other fields
};
If a .yaml or .yml file is passed as an entrypoint, it will be converted to a .js module that export defaults the parsed object.
InputOutputname: John Doe age: 35 email: johndoe@example.comtext Text loader. Default for .txt. The contents of the text file are read and inlined into the bundle as a string. Text files can be directly imported. The file is read and returned as a string.
import contents from "./file.txt";
console.log(contents); // => "Hello, world!"
// To import an html file as text
// The "type" attribute can be used to override the default loader.
import html from "./index.html" with { type: "text" };
When referenced during a build, the contents are inlined into the bundle as a string.
var contents = `Hello, world!`; console.log(contents);If a .txt file is passed as an entrypoint, it will be converted to a .js module that export defaults the file contents. InputOutput
Hello, world!napi Native addon loader. Default for .node. In the runtime, native addons can be directly imported.
import addon from "./addon.node"; console.log(addon);
import db from "./my.db" with { type: "sqlite" };
// embed the database into the bundle
import db from "./my.db" with { type: "sqlite", embed: "true" };
Loaders - Bun,AI智能索引,全网链接索引,智能导航,网页索引
- Built-in loaders for the Bun bundler and runtime