[WIP] github workflow

.github/workflows/scripts/install-flutter.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+BRANCH=$1
+
+if [ "$BRANCH" == "dev" ]
+then
+  # TODO Flutter dev branch is currently broken so we're unable to test MacOS.
+  echo "TODO: Skipping macOS testing due to Flutter dev branch issue. Switching branch to stable."
+  BRANCH=stable
+fi
+
+git clone https://github.com/flutter/flutter.git --depth 1 -b $BRANCH _flutter
+echo "::add-path::$GITHUB_WORKSPACE/_flutter/bin"

.github/workflows/scripts/install-tools.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+flutter pub global activate melos
+echo "::add-path::$HOME/.pub-cache/bin"
+echo "::add-path::$GITHUB_WORKSPACE/_flutter/.pub-cache/bin"
+echo "::add-path::$GITHUB_WORKSPACE/_flutter/bin/cache/dart-sdk/bin"

.github/workflows/scripts/validate-formatting.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+if [[ $(git ls-files --modified) ]]; then
+  echo ""
+  echo ""
+  echo "These files are not formatted correctly:"
+  for f in $(git ls-files --modified); do
+    echo ""
+    echo ""
+    echo "-----------------------------------------------------------------"
+    echo "$f"
+    echo "-----------------------------------------------------------------"
+    echo ""
+    git --no-pager diff --unified=0 --minimal $f
+    echo ""
+    echo "-----------------------------------------------------------------"
+    echo ""
+    echo ""
+  done
+  if [[ $GITHUB_WORKFLOW ]]; then
+    git checkout . > /dev/null 2>&1
+  fi
+  echo ""
+  echo "❌ Some files are incorrectly formatted, see above output."
+  echo ""
+  echo "To fix these locally, run: 'melos run format'."
+  exit 1
+else
+  echo ""
+  echo "✅ All files are formatted correctly."
+fi