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

src/dynamic/framework/adapters/pubsub_python.rs

@@ -0,0 +1,115 @@
+//! Phase 20 (Track M.2) — Python Google Pub/Sub subscriber adapter.
+
+use crate::dynamic::framework::{FrameworkAdapter, FrameworkBinding};
+use crate::evidence::EntryKind;
+use crate::summary::FuncSummary;
+use crate::symbol::Lang;
+
+pub struct PubsubPythonAdapter;
+
+const ADAPTER_NAME: &str = "pubsub-python";
+
+fn callee_is_pubsub(name: &str) -> bool {
+    let last = name.rsplit_once('.').map(|(_, s)| s).unwrap_or(name);
+    matches!(
+        last,
+        "subscribe" | "pull" | "callback" | "process_message"
+    )
+}
+
+fn source_imports_pubsub(file_bytes: &[u8]) -> bool {
+    const NEEDLES: &[&[u8]] = &[
+        b"google.cloud.pubsub",
+        b"from google.cloud import pubsub",
+        b"google.cloud.pubsub_v1",
+    ];
+    NEEDLES
+        .iter()
+        .any(|n| file_bytes.windows(n.len()).any(|w| w == *n))
+}
+
+fn extract_topic(file_bytes: &[u8]) -> String {
+    let text = std::str::from_utf8(file_bytes).unwrap_or("");
+    // Needles include the opening quote so we only need to find the
+    // closing one — avoids picking up the next literal after a comma.
+    for (needle, close) in [
+        (".subscribe(\"", '"'),
+        (".subscribe('", '\''),
+        ("subscription_path(\"", '"'),
+        ("subscription_path('", '\''),
+    ] {
+        if let Some(idx) = text.find(needle) {
+            let after = &text[idx + needle.len()..];
+            if let Some(end) = after.find(close) {
+                return after[..end].to_owned();
+            }
+        }
+    }
+    String::new()
+}
+
+impl FrameworkAdapter for PubsubPythonAdapter {
+    fn name(&self) -> &'static str {
+        ADAPTER_NAME
+    }
+
+    fn lang(&self) -> Lang {
+        Lang::Python
+    }
+
+    fn detect(
+        &self,
+        summary: &FuncSummary,
+        _ast: tree_sitter::Node<'_>,
+        file_bytes: &[u8],
+    ) -> Option<FrameworkBinding> {
+        let matches_call = super::any_callee_matches(summary, callee_is_pubsub);
+        let matches_source = source_imports_pubsub(file_bytes);
+        if matches_call || matches_source {
+            Some(FrameworkBinding {
+                adapter: ADAPTER_NAME.to_owned(),
+                kind: EntryKind::MessageHandler {
+                    queue: extract_topic(file_bytes),
+                    message_schema: None,
+                },
+                route: None,
+                request_params: Vec::new(),
+                response_writer: None,
+                middleware: Vec::new(),
+            })
+        } else {
+            None
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn parse_python(src: &[u8]) -> tree_sitter::Tree {
+        let mut parser = tree_sitter::Parser::new();
+        let lang = tree_sitter::Language::from(tree_sitter_python::LANGUAGE);
+        parser.set_language(&lang).unwrap();
+        parser.parse(src, None).unwrap()
+    }
+
+    #[test]
+    fn fires_on_pubsub_v1_subscribe() {
+        let src: &[u8] = b"from google.cloud import pubsub_v1\n\
+            def callback(message):\n    pass\n\
+            sub = pubsub_v1.SubscriberClient()\n\
+            sub.subscribe(\"projects/p/subscriptions/s\", callback=callback)\n";
+        let tree = parse_python(src);
+        let summary = FuncSummary {
+            name: "callback".into(),
+            ..Default::default()
+        };
+        let binding = PubsubPythonAdapter
+            .detect(&summary, tree.root_node(), src)
+            .expect("pubsub_v1 binds");
+        if let EntryKind::MessageHandler { queue, .. } = binding.kind {
+            assert_eq!(queue, "projects/p/subscriptions/s");
+        }
+    }
+}