Import a JSON file in typescript-CodePudding

I have JSON file that I want to access via the import statement. I don't want to expose the name directly in the code but read the name from the .env file and import it.

Here is a snippet of my code that works from directly importing the file. How can I change it so that I can read the file name from .env and import the actual file

import keys from 'home/path/account.json';
class SecurityServices {
   getToken(){
     return keys.certs;
   }
}

basically I have the env file with the path and I was import it in my typescript code.

.env { "keyFile":"home/path/account.json'" }

Thanks

CodePudding user response：

I'd use something like https://www.npmjs.com/package/properties-reader

Load the properties from a file using that. Put it in an object, import that object file and use the property. For example

let PropertiesReader = require('properties-reader');
let properties = null;
try {
    debugLog('Looking for '   os.homedir()   '/app.properties')
    properties = PropertiesReader(os.homedir()   '/app.properties');
    debugLog('Found '   os.homedir()   '/app.properties')
} catch(e) {
    debugLog(os.homedir()   '/app.properties'   ' not found.  Using default properties')
}

then

const prop = properties.get(name);

CodePudding user response：

If you just want to replace a bit of text at build time, bundlers like rollup are the tool for you. For example:

// file.ts
import keys from 'home/path/account.json';

// rollup.config.js
import replace from '@rollup/plugin-replace';

export default {
  client: {
    plugins: [
      replace({ 'home/path/account.json': process.env.keyFile })

You should be able to accomplish something similar with webpack, gulp, and most other modern bundlers.

Alternatively (and my preference), consider doing a dynamic import. Note that this requires using Promises adding an async factor to your code:

let _loadedJson: any = null;

export async function getJsonFromFile() {
  if (_loadedJson === null) {
    // This dynamic import will happen one time, when this is first called.
    _loadedJson = await import(process.env.keyFile);
  }
  // Optionally assert a type at return since dynamic imports resolve to `any`.
  return _loadedJson as Record<string, any>
}

With this approach, you reduce the initial build size at the cost of needing to work with the JSON asynchronously.