IMPROVE: Add plugin metadata workflow with version check (#149)

* IMPROVE: Add plugin metadata workflow with version check

* Update error message

* Fix workflow keys

* Update plugin-metadata.yml

* Update plugin-metadata.yml

* Update plugin-metadata.yml

* bump version

* Update plugin-metadata.yml

* Update plugin-metadata.yml

* Use npm semver to compare versions

* Fix syntax

* Add semver to package.json

* Update npm usage

* Update plugin-metadata.yml

* Update plugin-metadata.yml

* purposefully fail test

* Pass test

.github/workflows/plugin-metadata.yml

@@ -0,0 +1,44 @@
+name: Metadata
+
+on:
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout head repository
+        uses: actions/checkout@v2
+
+      - name: Store head version
+        run: |
+          sed -n -e 's/^.*version: /head_version=/p' plugin.rb >> $GITHUB_ENV
+
+      - name: Checkout base repository
+        uses: actions/checkout@v2
+        with:
+          ref: "${{ github.base_ref }}"
+
+      - name: Store base version
+        run: |
+          sed -n -e 's/^.*version: /base_version=/p' plugin.rb >> $GITHUB_ENV
+
+      - name: Setup node
+        uses: actions/setup-node@v2
+        with:
+          node-version: 14
+
+      - name: Install semver
+        run: npm install --include=dev
+
+      - name: Check version
+        uses: actions/github-script@v5
+        with:
+          script: |
+              const semver = require('semver');
+              const { head_version, base_version } = process.env;
+
+              if (semver.lte(head_version, base_version)) {
+                core.setFailed("Head version is equal to or lower than base version.");
+              }

package.json

@@ -5,6 +5,7 @@
   "author": "Pavilion",
   "license": "GPL V2",
   "devDependencies": {
-    "eslint-config-discourse": "^1.1.8"
+    "eslint-config-discourse": "^1.1.8",
+    "semver": "^7.3.5"
   }
-}
+}

plugin.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 # name: discourse-custom-wizard
 # about: Create custom wizards
-# version: 1.15.0
+# version: 1.15.1
 # authors: Angus McLeod
 # url: https://github.com/paviliondev/discourse-custom-wizard
 # contact emails: angus@thepavilion.io