How to set NODE_ENV on Amplify for React app - reactjs

Question

I am trying to run multiple environments of an AWS Amplify react app. So have set up a single environment, created two versions pointing to a master and a staging branch of GIT, assigned them to two different domains, and all working.
However, now I need to start one as production and one as staging so dotenv will read .env.production and .env.staging. (which is my actual objective :) )
So I set up an environment variable called NODE_ENV and set it to staging and production. However, Amplify seems to ignore it, and if I print out the environment variables, I get production on both systems
And the output from console.log(process.env)
Object
FAST_REFRESH: true
NODE_ENV: "production"
PUBLIC_URL: ""

Answer 1

OK, so I may have found a solution, it AIN'T pretty, but it works for me.
My solution is
Create two files,
env.production
env.stagign
Notice the missing .
They will be like your good old .env files
REACT_APP_VARIABLE=VALUE
Then you create an environment variable called BUILD_ENV like above, with an override. In my case, I have a master and staging based on the git branches.
The ugly magic comes in the build script. In amplify.yml we'll add BUILD_ENV, one line to write it, because I had a lot of problems getting it to work.
The second is that we add a new build type, called build:$BUILD_ENV
version: 2
frontend:
phases:
preBuild:
commands:
- npm ci
build:
commands:
- echo "Build environment is ${BUILD_ENV}"
- npm run build:${BUILD_ENV}
artifacts:
baseDirectory: build
files:
- '**/*'
cache:
paths:
- node_modules/**/*
The last step is that we need to get around that react build cares little about what you want to do, so we'll just build production, but with our env. So we will copy the relevant env.environment to .env.production I told you it would be ugly :)
"scripts": {
"start": "PORT=8082 react-scripts start",
"build": "react-scripts build",
"build:staging": "cp env.staging .env.production && NODE_ENV=staging react-scripts build",
"build:production": "cp env.production .env.production && react-scripts build",
=========================================
So the problem is (I think) that between react, node, AWS amplify, there are a lot of people who feel that things should be in very specific ways, like react deciding that there can only be production and dev, and amplify limiting what we're allowed to do to the environment in regards to variables.
This is probably not the right way of doing this, but it DOES work, so that's OK?