Hi, can you give me the javascript code that will generate an import map for a given package.json so that code works in web browsers without any kind of building?
Certainly! Below is a JavaScript code snippet that generates an import map for a given package.json
file. This code assumes that the dependencies in the package.json
are already downloaded and placed in a folder named node_modules
within your project directory, and it generates an import map compatible with native ES modules in web browsers without requiring a build step.
const fs = require("fs");
function generateImportMap(packageJsonPath) {
const packageJsonContent = fs.readFileSync(packageJsonPath, "utf-8");
const packageJson = JSON.parse(packageJsonContent);
if (!packageJson.dependencies) {
console.error("No dependencies found in package.json");
return;
}
const importMap = {
imports: {},
};
for (const [packageName, packageVersion] of Object.entries(packageJson.dependencies)) {
const packagePath = `./node_modules/${packageName}/package.json`;
const packageContent = fs.readFileSync(packagePath, "utf-8");
const packageData = JSON.parse(packageContent);
if (!packageData.module) {
console.error(`The package ${packageName} does not have a module entry.`);
continue;
}
const modulePath = `./node_modules/${packageName}/${packageData.module}`;
importMap.imports[packageName] = modulePath;
}
fs.writeFileSync("import-map.json", JSON.stringify(importMap, null, 2), "utf-8");
console.log("Import map has been generated: import-map.json");
}
// Replace the path below with the path to your package.json file
generateImportMap("./path/to/your/package.json");
To use this script, create a file named generate-import-map.js
in your project directory and paste the code above into the file. Replace ./path/to/your/package.json
with the path to your package.json
file. Then, run the script using Node.js:
node generate-import-map.js
The script will generate an import-map.json
file in the project directory. To use the import map in your HTML file, add the following code within the <head>
tag:
<script type="importmap" src="import-map.json"></script>
Now, you can use the native ES modules in your JavaScript code, importing packages directly from your node_modules
folder:
import { functionName } from "package-name";