test: add unit + integration tests for tf-docs (8 passing)

server.js

@@ -125,6 +125,17 @@ const server = http.createServer((req, res) => {
 </html>`);
 });
 
-server.listen(PORT, () => {
+if (require.main === module) {
+  server.listen(PORT, () => {
     console.log(`[${SERVICE}] listening on :${PORT} (version ${VERSION})`);
-});
+  });
+}
+
+module.exports = {
+  getDocsCandidates,
+  contentTypeFor,
+  health,
+  docsHandler,
+  server,
+  s3,
+};