💚 add publish workflow

Author: BirjuVachhani

.github/workflows/publish.yaml

@@ -0,0 +1,25 @@
+name: Dart CI
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image:  google/dart:latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install Flutter
+        uses: subosito/flutter-action@v1
+        with:
+          channel: 'stable'
+      - name: Install dependencies
+        run: flutter packages get
+      - name: Code Formatting
+        run: dartfmt -w .
+      - name: Check Publish Warnings
+        run: pub publish --dry-run
+      - name: Publish Package
+        run: pub publish -f

pub_login.sh

@@ -0,0 +1,35 @@
+# This script creates/updates credentials.json file which is used
+# to authorize publisher when publishing packages to pub.dev
+
+# Checking whether the secrets are available as environment
+# variables or not.
+if [ -z "${PUB_DEV_PUBLISH_ACCESS_TOKEN}" ]; then
+  echo "Missing PUB_DEV_PUBLISH_ACCESS_TOKEN environment variable"
+  exit 1
+fi
+
+if [ -z "${PUB_DEV_PUBLISH_REFRESH_TOKEN}" ]; then
+  echo "Missing PUB_DEV_PUBLISH_REFRESH_TOKEN environment variable"
+  exit 1
+fi
+
+if [ -z "${PUB_DEV_PUBLISH_TOKEN_ENDPOINT}" ]; then
+  echo "Missing PUB_DEV_PUBLISH_TOKEN_ENDPOINT environment variable"
+  exit 1
+fi
+
+if [ -z "${PUB_DEV_PUBLISH_EXPIRATION}" ]; then
+  echo "Missing PUB_DEV_PUBLISH_EXPIRATION environment variable"
+  exit 1
+fi
+
+# Create credentials.json file.
+cat <<EOF >~/.pub-cache/credentials.json
+{
+  "accessToken":"${PUB_DEV_PUBLISH_ACCESS_TOKEN}",
+  "refreshToken":"${PUB_DEV_PUBLISH_REFRESH_TOKEN}",
+  "tokenEndpoint":"${PUB_DEV_PUBLISH_TOKEN_ENDPOINT}",
+  "scopes":["https://www.googleapis.com/auth/userinfo.email","openid"],
+  "expiration":${PUB_DEV_PUBLISH_EXPIRATION}
+}
+EOF