flutterw

#!/bin/bash

# Use this flutter wrapper to bundle flutter within your project to make sure everybody builds with the same version
# put `flutterw` into the root of your flutter project and execute it. It will download all dependencies automatically when calling it.
# Use `./flutterw upgrade` to upgrade the flutter version, using the channel defined in flutter/wrapper/flutter-wrapper.properties

FLUTTERW_DIR="$(pwd -P)/flutter/wrapper"
FLUTTER_DIR="$(pwd -P)/.flutter"
WRAPPER_PROPERTIES="$FLUTTERW_DIR/flutter-wrapper.properties"
FLUTTER_REPO_URL="https://github.com/flutter/flutter.git"

DEFAULT_CHANNEL="alpha"

# Check if wrapper config file exists otherwise create with default values
if [ ! -d $FLUTTERW_DIR ]; then
    mkdir -p $FLUTTERW_DIR
fi

# Create wrapper properties file if it doesn't exit
if [ ! -f $WRAPPER_PROPERTIES ]; then
    # Use alpha here as recommended, will be replaced with explicit sha1 once cloned
    echo "flutter_channel=$DEFAULT_CHANNEL" > $WRAPPER_PROPERTIES
fi

# read all properties from config file
while IFS='=' read -r key value; do
    key=$(echo $key | tr '.' '_')
    eval "${key}='${value}'"
done < "$WRAPPER_PROPERTIES"


# Clone Flutter when not already cloned in project dir, the outer git repo will ignore this sub repo
if [ ! -d $FLUTTER_DIR ]; then
    echo "Downloading Flutter with wrapper"
    git clone $FLUTTER_REPO_URL $FLUTTER_DIR
fi

upgradeWrapperConfigFile () {
    FLUTTER_SHA1="$(git -C $FLUTTER_DIR rev-parse HEAD)"
    if [ ! -z "$FLUTTER_SHA1" ]; then
        # Write config file with updated version
        echo "flutter_channel=$flutter_channel" > $WRAPPER_PROPERTIES
        echo "flutter_version=$FLUTTER_SHA1" >> $WRAPPER_PROPERTIES
    else
        echo "Error: could not get version from flutter repo"
        exit 1
    fi
}

FLUTTER_SHA1="$(git -C $FLUTTER_DIR rev-parse HEAD)"

# When wrapper file version was changed, update flutter accordingly before executing
if [ "$flutter_version" != "$FLUTTER_SHA1" ]; then
    # use version when available, otherwise the channel on initial checkout
    if [ -z $flutter_version ]; then REV="$flutter_channel"; else REV="$flutter_version"; fi

    echo "Change Flutter version to $REV"

    git -C $FLUTTER_DIR checkout $REV -q
    upgradeWrapperConfigFile

    # when changing version also update binaries
    echo "Upgrading engine"
    $FLUTTER_DIR/bin/flutter precache
    $FLUTTER_DIR/bin/flutter packages upgrade
fi

# Flutter wrapper operates with detached HEAD. Upgrade won't work, flutter has to be on a branch to pull
# Checkout channel before upgrading
if [[ $@ == *"upgrade"* ]]; then
    echo "Switch to channel '$flutter_channel' before upgrading"
    git -C $FLUTTER_DIR checkout $flutter_channel -q
fi

set -e
"$FLUTTER_DIR/bin/flutter" "$@"


# Automatically update the flutter version in wrapper after upgrade; or at initial run without existing version
if [[ $@ == *"upgrade"* ]]; then
    upgradeWrapperConfigFile
fi