Danger: Fail/warn when PR targets wrong base branch

.github/workflows/danger-js.yml

@@ -8,8 +8,7 @@ on:
       - unlabeled
       - edited
     branches:
-      - main
-      - next
+      - "**"
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.number }}

scripts/dangerfile.js

@@ -13,7 +13,7 @@
  * Why: We want Danger to run as fast as possible in CI without installing dependencies or running
  * build processes.
  */
-import { danger, fail } from 'danger';
+import { danger, fail, warn } from 'danger';
 
 /**
  * Returns the intersection of two arrays
@@ -145,6 +145,28 @@ const checkManualTestingSection = (body) => {
   }
 };
 
+const checkTargetBranch = () => {
+  const targetBranch = danger.github.pr.base.ref;
+  const authorAssociation = danger.github.pr.author_association;
+
+  // Only check for non-team members (not OWNER or MEMBER)
+  if (['OWNER', 'MEMBER'].includes(authorAssociation)) {
+    return;
+  }
+
+  if (targetBranch === 'main' || targetBranch.includes('release')) {
+    fail(
+      `This PR targets \`${targetBranch}\`, but it should target \`next\`. Please update the base branch of your PR.`
+    );
+  } else if (targetBranch !== 'next') {
+    warn(
+      `This PR targets \`${targetBranch}\`. The default branch for contributions is \`next\`. Please make sure you are targeting the correct branch.`
+    );
+  }
+};
+
+checkTargetBranch();
+
 if (prLogConfig) {
   checkRequiredLabels(labels.map((l) => l.name));
   checkPrTitle(danger.github.pr.title);