ci: Run pub publish from CI

.gitlab-ci.yml

@@ -2,6 +2,7 @@ stages:
   - coverage
   - builddocs
   - deploy
+  - publish
 
 test:
   tags:
@@ -48,4 +49,52 @@ pages:
     paths:
       - public
   only:
-    - main
+    - main
+
+dry-run:
+  stage: publish
+  image: google/dart
+  script:
+    - dart pub get
+    - dart pub publish --dry-run
+  only:
+    - merge_requests
+
+pub-dev:
+  stage: publish
+  image: google/dart
+  script:
+    - |
+      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
+
+      cat <<EOF > ~/.pub-cache/credentials.json
+      {
+        "accessToken":"$(echo "${PUB_DEV_PUBLISH_ACCESS_TOKEN}" | base64 -d)",
+        "refreshToken":"$(echo "${PUB_DEV_PUBLISH_REFRESH_TOKEN}" | base64 -d)",
+        "tokenEndpoint":"${PUB_DEV_PUBLISH_TOKEN_ENDPOINT}",
+        "scopes":["https://www.googleapis.com/auth/userinfo.email","openid"],
+        "expiration":${PUB_DEV_PUBLISH_EXPIRATION}
+      }
+      EOF
+    - dart pub get
+    - dart pub publish --dry-run
+  only:
+    - tags