[pitboss] phase 20: Track M.2 — MessageHandler end-to-end (Kafka / SQS / Pub-Sub / NATS / RabbitMQ)

src/dynamic/stubs/broker_pubsub.rs

@@ -0,0 +1,100 @@
+//! Phase 20 (Track M.2) — Google Pub/Sub broker loopback stub.
+//!
+//! Mints `google.cloud.pubsub_v1.subscriber.message.Message`-shaped
+//! envelopes (`message_id`, `data`, `ack`, `nack`) for Python / Go.
+
+use crate::symbol::Lang;
+
+/// Stdout sentinel the per-lang harness prints once per publish.
+pub const PUBSUB_PUBLISH_MARKER: &str = "__NYX_BROKER_PUBLISH__:pubsub";
+
+/// Source snippet declaring an in-process Pub/Sub loopback for `lang`.
+pub fn pubsub_source(lang: Lang) -> &'static str {
+    match lang {
+        Lang::Python => {
+            r#"
+class NyxPubsubMessage:
+    def __init__(self, mid, data):
+        self.message_id = mid
+        self.data = data if isinstance(data, (bytes, bytearray)) else data.encode('utf-8', 'replace')
+        self.acked = False
+        self.nacked = False
+    def ack(self): self.acked = True
+    def nack(self): self.nacked = True
+
+class NyxPubsubLoopback:
+    def __init__(self):
+        self._subs = {}
+        self._mid = 0
+    def subscribe(self, topic, cb):
+        self._subs.setdefault(topic, []).append(cb)
+    def publish(self, topic, payload):
+        self._mid += 1
+        msg = NyxPubsubMessage(f'nyx-{self._mid:08d}', payload)
+        for cb in self._subs.get(topic, []):
+            cb(msg)
+"#
+        }
+        Lang::Go => {
+            r#"
+type NyxPubsubMessage struct {
+    ID    string
+    Data  []byte
+    Acked bool
+}
+
+func (m *NyxPubsubMessage) Ack()  { m.Acked = true }
+func (m *NyxPubsubMessage) Nack() { m.Acked = false }
+
+type NyxPubsubLoopback struct {
+    subs map[string][]func(*NyxPubsubMessage)
+    mid  int
+}
+
+func NewNyxPubsubLoopback() *NyxPubsubLoopback {
+    return &NyxPubsubLoopback{subs: map[string][]func(*NyxPubsubMessage){}}
+}
+
+func (l *NyxPubsubLoopback) Subscribe(topic string, cb func(*NyxPubsubMessage)) {
+    l.subs[topic] = append(l.subs[topic], cb)
+}
+
+func (l *NyxPubsubLoopback) Publish(topic string, payload string) {
+    l.mid += 1
+    msg := &NyxPubsubMessage{ID: fmt.Sprintf("nyx-%08d", l.mid), Data: []byte(payload)}
+    for _, cb := range l.subs[topic] {
+        cb(msg)
+    }
+}
+"#
+        }
+        _ => "",
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn marker_stable() {
+        assert_eq!(PUBSUB_PUBLISH_MARKER, "__NYX_BROKER_PUBLISH__:pubsub");
+    }
+
+    #[test]
+    fn python_carries_ack_nack_surface() {
+        let src = pubsub_source(Lang::Python);
+        assert!(src.contains("class NyxPubsubMessage"));
+        assert!(src.contains("def ack"));
+        assert!(src.contains("def nack"));
+        assert!(src.contains("message_id"));
+    }
+
+    #[test]
+    fn go_carries_ack_nack_methods() {
+        let src = pubsub_source(Lang::Go);
+        assert!(src.contains("type NyxPubsubMessage struct"));
+        assert!(src.contains("func (m *NyxPubsubMessage) Ack"));
+        assert!(src.contains("NewNyxPubsubLoopback"));
+    }
+}