1 files changed, 41 insertions, 0 deletions
diff --git a/u/server/filter/method.ts b/u/server/filter/method.ts
new file mode 100644
index 0000000..6b0419d
--- /dev/null
+++ b/u/server/filter/method.ts
@@ -0,0 +1,41 @@
+import {
+  Either,
+  type ITraceable,
+  LogLevel,
+  PenguenoError,
+  type PenguenoRequest,
+  type RequestFilter,
+  type ServerTrace,
+  TraceUtil,
+} from "@emprespresso/pengueno";
+
+type HttpMethod =
+  | "POST"
+  | "GET"
+  | "HEAD"
+  | "PUT"
+  | "DELETE"
+  | "CONNECT"
+  | "OPTIONS"
+  | "TRACE"
+  | "PATCH";
+
+export const requireMethod = (
+  methods: Array<HttpMethod>,
+): RequestFilter<HttpMethod> =>
+(req: ITraceable<PenguenoRequest, ServerTrace>) =>
+  req.bimap(TraceUtil.withFunctionTrace(requireMethod))
+    .move(Promise.resolve(req.get()))
+    .map(TraceUtil.promiseify((t) => {
+      const { method: _method } = t.get();
+      const method = <HttpMethod> _method;
+      if (!methods.includes(method)) {
+        const msg = "that's not how you pet me (⋟﹏⋞)~";
+        t.trace.addTrace(LogLevel.WARN).trace(msg);
+        return Either.left<PenguenoError, HttpMethod>(
+          new PenguenoError(msg, 405),
+        );
+      }
+      return Either.right<PenguenoError, HttpMethod>(method);
+    }))
+    .get();