Add CI scripts and workflow for forgejo

scripts/tagExists.mjs

@@ -0,0 +1,38 @@
+import axios from "axios";
+
+const {
+	TAG_NAME,
+	FORGEJO_API_URL: API_URL,
+	FORGEJO_REPOSITORY: REPO,
+	FORGEJO_TOKEN: TOKEN,
+} = process.env;
+
+
+async function main() {
+
+	if (!TAG_NAME) {
+		console.log(`Tag name must not be blank`);
+		process.exit(1);
+	};
+
+	const requestURL = `${API_URL}/repos/${REPO}/tags/${TAG_NAME}`;
+
+	const response = await axios.get(
+		requestURL,
+		{
+			headers: { Authorization: `token ${TOKEN}` },
+			validateStatus: () => true,
+		},
+	);
+
+	// We actually *want* an error when the tag exists, instead of when
+	// it doesn't
+	if (response.status === 200) {
+		console.log(`Tag with name "${TAG_NAME}" already exists`);
+		process.exit(1);
+	};
+
+	console.log(`Tag with name "${TAG_NAME}" not found, proceeding`);
+};
+
+main();