Flutter CLI still doesn't support passing full environment files, just single values. This script group env vars for passing as `--dart-define=` values.

flutter_run.sh

#!/bin/bash

FLUTTER_RUN="flutter run"

if [ ! -z "$1" ]
then
    SUPPLIED_ENV_FILE="$1"
    while IFS= read -r line
    do
      FLUTTER_RUN="$FLUTTER_RUN --dart-define=$line"

    done < "$SUPPLIED_ENV_FILE"
fi

source $FLUTTER_RUN

# 1. Set env file as:
#
# KEY=value
# 
# 2. Pass `.env` file as argument and run:
# $ ./flutter_run.sh .env

Hi, thanks for your script. I was trying this out on Mac but I saw only the first line of my config file processed. Please see the below change that worked (from https://stackoverflow.com/a/10929511): just added || [[ -n "$line" ]] to the while loop.

#!/bin/bash

FLUTTER_RUN="flutter run"

if [ ! -z "$1" ]
then
    SUPPLIED_ENV_FILE="$1"
    while IFS= read -r line || [[ -n "$line" ]];
    do
      FLUTTER_RUN="$FLUTTER_RUN --dart-define=$line"

    done < "$SUPPLIED_ENV_FILE"
fi

source $FLUTTER_RUN

# 1. Set env file as:
#
# KEY=value
# 
# 2. Pass `.env` file as argument and run:
# $ ./flutter_run.sh .env