vite-plugin-require-transform

A vite plugin that converts the code from require syntax to import

Why vite-plugin-require-transform

"require syntax" is supported when develop with Webpack cause it transformed it internally.

but when serve with Vite error "require is not defined" will show up.

This plugin amis to support require when serve with vite.

Install

yarn add -D vite-plugin-require-transform

or

npm i vite-plugin-require-transform --save-dev

Usage

// vite.config.(t|j)s

import { defineConfig } from 'vite';

/**
 * @param match
 * Regular expression in string or Regexp type,
 *  or a match predicate  (this: vite transform context, code: string, id: file name string) => void
 * @returns transformed code
 */
import requireTransform from 'vite-plugin-require-transform';

export default defineConfig({
  plugins: [
    // passing string type Regular expression
    requireTransform({}),
  ],
});

// check the vite-plugin-require-transform params'type 
export type VitePluginRequireTransformParamsType = {
    //filter files that should enter the plugin
    fileRegex?: RegExp = /.ts$|.tsx$/ ,
    //prefix that would plugin into the requireSpecifier 
    importPrefix? = '_vite_plugin_require_transform_': string,
    //to deal with the requireSpecifier
    importPathHandler?: Function
}

What vite-plugin-require-transform actually do

you can also check the test directory to see the cases.

case 1:

const case1 = require("case1");
console.log("case1", case1)

will be transformed into

import _vite_plugin_require_transform_case1 from "case1";
const case1 = _vite_plugin_require_transform_case1;
console.log("case1", case1);

case 2:

example A

const case2A = location.host == 'test' ? null : require("case2");

if(location.host == 'test1' ){
    case2A.start();
}

case2A.stop();

will be transformed into

import { start as _vite_plugin_require_transform_case2start, stop as _vite_plugin_require_transform_case2stop } from "case2";
const _vite_plugin_require_transform_case2 = {
  start: _vite_plugin_require_transform_case2start,
  stop: _vite_plugin_require_transform_case2stop
};
const case2A = location.host == 'test' ? null : _vite_plugin_require_transform_case2;

if (location.host == 'test1') {
  case2A.start();
}

case2A.stop();

example B

const case2B = {
    test:require('test2B').Something
}

will be transformed into

import { Something as _vite_plugin_require_transform_test2BSomething } from "test2B";
const case2B = {
  test: _vite_plugin_require_transform_test2BSomething
};

example C

const case2c =require('test2C')

case2c.forEach((item)=>{
    console.log('item',item)
})

will be transformed into

import _vite_plugin_require_transform_test2C from "test2C";
const case2c = _vite_plugin_require_transform_test2C;
case2c.forEach(item => {
  console.log('item', item);
});

case 3:

when exist a case as same fileName,different extensions,by default it would be error cause the plugin only capture the path without extension.

//same path,different extension
const testCaseA = require("caseA.extA?aaa");
const testCaseB = require("caseA.extB?bbb");

console.log("caseA", testCaseA)
console.log("caseB", testCaseB)

so we need to make a importPathHandler to deal with the situtation

//check out __test__/index
glob("__test__/case3/*.ts", {
    ignore: "**/*transformed_result.ts"
}, async (err, files) => {
    for (const file of files) {
        const fileContent = readFileSync(file, 'utf-8');
        const transformedContent = await vitePluginRequireTransform(
            {
                importPathHandler: (requirePath: string) => {
                    return requirePath.replace('.', '_').replace('?', "_");
                }
            }
        ).transform(fileContent, file);
        writeFileSync(file.replace('.ts', '_transformed_result.ts'), transformedContent.code);
    }
})  

will be transformed into

import _vite_plugin_require_transform_caseA_extB_bbb from "caseA.extB?bbb";
import _vite_plugin_require_transform_caseA_extA_aaa from "caseA.extA?aaa";
//same path,different extension
const testCaseA = _vite_plugin_require_transform_caseA_extA_aaa;
const testCaseB = _vite_plugin_require_transform_caseA_extB_bbb;
console.log("caseA", testCaseA);
console.log("caseB", testCaseB);