React JS run-script build fails to compile - node.js

Question

Problem description
>> npm run-script build fails to compile
Expected behavior
Successful compile, build folder contains a minified project, no errors in output
Actual behavior
Output gives out the following error:
react-scripts build
Creating an optimized production build...
Failed to compile.
Failed to minify the bundle. Error: static/js/main.e3925110.chunk.js from Terser
Name expected [static/js/main.e3925110.chunk.js:186,5]
at compiler.run (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\react-scripts\scripts\build.js:176:23)
at finalCallback (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compiler.js:257:39)
at hooks.done.callAsync.err (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compiler.js:273:13)
at AsyncSeriesHook.eval [as callAsync] (eval at create (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\HookCodeFactory.js:33:10), <anonymous>:6:1)
at AsyncSeriesHook.lazyCompileHook (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\Hook.js:154:20)
at onCompiled (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compiler.js:271:21)
at hooks.afterCompile.callAsync.err (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compiler.js:671:15)
at AsyncSeriesHook.eval [as callAsync] (eval at create (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\HookCodeFactory.js:33:10), <anonymous>:6:1)
at AsyncSeriesHook.lazyCompileHook (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\Hook.js:154:20)
at compilation.seal.err (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compiler.js:668:31)
at AsyncSeriesHook.eval [as callAsync] (eval at create (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\HookCodeFactory.js:33:10), <anonymous>:6:1)
at AsyncSeriesHook.lazyCompileHook (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\Hook.js:154:20)
at hooks.optimizeAssets.callAsync.err (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compilation.js:1385:35)
at AsyncSeriesHook.lazyCompileHook (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\tapable\lib\Hook.js:154:20)
at hooks.optimizeChunkAssets.callAsync.err (C:\Users\Zackyy\Desktop\ReactCoding\wanawiipuri\node_modules\webpack\lib\Compilation.js:1376:32)
Read more here: *removed*
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! wanawiipuri#0.1.0 build: `react-scripts build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the wanawiipuri#0.1.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Zackyy\AppData\Roaming\npm-cache\_logs\2019-09-20T15_06_48_248Z-debug.log
Possible fixes that also failed
Stackoverflow community had a few solutions to this. First one being npm i react-scripts --save-dev, which did not make a difference.
Second being npm i terser#3.14.1 --save, also no progress.
Package.json
{
"name": "wanawiipuri",
"version": "0.1.0",
"private": true,
"dependencies": {
"firebase": "^6.6.1",
"firebase-admin": "^8.6.0",
"firebase-redux": "0.0.5",
"firebase-tools": "^7.3.2",
"react": "^16.9.0",
"react-dom": "^16.9.0",
"react-redux": "^7.1.1",
"react-redux-firebase": "^2.4.1",
"react-router-dom": "^5.0.1",
"redux": "^4.0.4",
"redux-firestore": "^0.9.0",
"redux-thunk": "^2.3.0",
"universal-cookie": "^4.0.2"
},
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test",
"eject": "react-scripts eject"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": {
"production": [
">0.2%",
"not dead",
"not op_mini all"
],
"development": [
"last 1 chrome version",
"last 1 firefox version",
"last 1 safari version"
]
},
"devDependencies": {
"react-scripts": "^3.1.2",
"terser": "^3.14.1"
}
}
Additional info
Project created using npx create-react-app. /
Windows 10 1903, /
VSCode /
ReactJS library /
Firebase hosting/firestore initialized /
I'm using npm, and I've got no idea if yarn-based possible fixes can do anything. Even though I tried, nothing worked so far.
**EDIT:
Also tried completely removing terser and installing both Terser#3.14.1 and then removing it and installing Terser#3.16.1 to test if any of the version work. No difference between versions.
Also tried installing terser as a dependency, both 3.14.1 and 3.16.1. Nothing works.
The build is not possible only with this project. Older projects are built successfully. Currently trying to find out what might have caused it.

Answer 1

I do not know HOW nor WHY, but the following solution worked for me.
I have this index.js file with code connecting firebase with my react. There was this line:
import { env } from './.env';
that is later used in
ReactDOM.render(<Provider store={store}><App env={env} /></Provider>, document.getElementById('root'));
So what I did is just commented out the import line and the env={env} part. NO IDEA why it worked, nor if I'll need it in the future, but this solved the problem for me.

Answer 2

This should be resolved in terser v3.16.1 - try to update your terser devDependency, as you are at v3.14.1.

Answer 3

In my case trying to require and old code gives the error:
from Terser Name expected
looking at code there was an:
var example, let;
let is a reserved name in ES6 like const etc... Be careful importing old code :)