add basic pr tests

tests/pr.test.js

@@ -0,0 +1,23 @@
+if (!process.env.PULL_REQUEST) return;
+
+const t = require("ava");
+const fs = require("fs-extra");
+const path = require("path");
+
+const PR_AUTHOR = process.env.PR_AUTHOR;
+const MODIFIED_FILES = process.env.MODIFIED_FILES.split(",");
+
+const domainsPath = path.resolve("domains");
+
+const admins = require("../util/administrators.json");
+
+t("Modified JSON files must be owned by the PR author", (t) => {
+    MODIFIED_FILES.forEach((file) => {
+        const domain = fs.readJsonSync(path.join(domainsPath, file));
+
+        t.true(
+            domain.owner.username === PR_AUTHOR || admins.includes(PR_AUTHOR),
+            `${file}: Owner should be ${PR_AUTHOR} but is ${domain.owner}`
+        );
+    });
+});