nodejs's require caches the module. the cached result is used for second call of require

func1.js

console.log(`\tfunc1 top\n`);

module.exports = () => {
    console.log(`\tfunc1 function\n`);
}

func2.js

console.log(`\tfunc2 top\n`);

module.exports = ()=>{
    console.log(`\tfunc2 function\n`);
}

index.js

console.log(`indexjs top\n`);
console.log(`load func1.`)
const func1_1 = require(`./func1`);
const func1_2 = require(`./func1`);
console.log(`func1 loaded.`)
func1_1();
func1_2();
console.log(`func1 executed.`)

console.log(`load func2.`)
const func2_1 = require(`./func2`);
const func2_2 = require(`./func2`);
console.log(`func2 loaded.`)
func2_1();
func2_2();
console.log(`func2 executed.`)

Investivate_behavior_of_nodejs_require

title

result.txt

my_terminal_home % node ../moduleTest/index.js
indexjs top

load func1.
        func1 top

func1 loaded.
        func1 function

        func1 function

func1 executed.
load func2.
        func2 top

func2 loaded.
        func2 function

        func2 function

func2 executed.

func1 and func2 called twice, but, the result shows "func1 top" and "func2 top" showed once.

each module is cached by nodejs runtime.