[pitboss] phase 13: Track L.11 — Express / Koa / NestJS / Fastify adapters

src/dynamic/framework/adapters/js_express.rs

@@ -0,0 +1,166 @@
+//! Express [`super::super::FrameworkAdapter`] (Phase 13 — Track L.11).
+//!
+//! Recognises `app.get('/path', handler)`, `app.post('/path', handler)`,
+//! `router.put('/path', handler)`, and the rest of the Express verb
+//! dispatch surface (`get` / `head` / `post` / `put` / `patch` /
+//! `delete` / `del` / `options` / `all`).  Middleware-chained
+//! registrations (`app.get('/x', authz, validate, handler)`) bind to
+//! the last positional argument that references `summary.name`.
+//!
+//! Receiver aliases follow Express convention: bare `app`,
+//! `application`, `router`, `api`, plus any name ending in `_router` /
+//! `_app` / `Router` / `App`.  Source-import sniffing requires one of
+//! the well-known Express stanzas before the AST walk runs.
+
+use crate::dynamic::framework::{FrameworkAdapter, FrameworkBinding, RouteShape};
+use crate::evidence::EntryKind;
+use crate::summary::FuncSummary;
+use crate::symbol::Lang;
+use tree_sitter::Node;
+
+use super::js_routes::{
+    bind_path_params, find_function_params, find_route_registration, function_formal_names,
+    source_imports_express,
+};
+
+pub struct JsExpressAdapter;
+
+const ADAPTER_NAME: &str = "js-express";
+
+fn receiver_looks_like_express(name: &str) -> bool {
+    matches!(
+        name,
+        "app" | "application" | "router" | "api" | "expressApp" | "server"
+    ) || name.ends_with("_router")
+        || name.ends_with("_app")
+        || name.ends_with("Router")
+        || name.ends_with("App")
+}
+
+impl FrameworkAdapter for JsExpressAdapter {
+    fn name(&self) -> &'static str {
+        ADAPTER_NAME
+    }
+
+    fn lang(&self) -> Lang {
+        Lang::JavaScript
+    }
+
+    fn detect(
+        &self,
+        summary: &FuncSummary,
+        ast: Node<'_>,
+        file_bytes: &[u8],
+    ) -> Option<FrameworkBinding> {
+        if !source_imports_express(file_bytes) {
+            return None;
+        }
+        let recv = receiver_looks_like_express;
+        let (method, path) = find_route_registration(ast, file_bytes, &summary.name, &recv)?;
+        let formals = find_function_params(ast, file_bytes, &summary.name)
+            .map(|p| function_formal_names(p, file_bytes))
+            .unwrap_or_default();
+        let request_params = bind_path_params(&formals, &path);
+        Some(FrameworkBinding {
+            adapter: ADAPTER_NAME.to_owned(),
+            kind: EntryKind::HttpRoute,
+            route: Some(RouteShape { method, path }),
+            request_params,
+            response_writer: None,
+            middleware: Vec::new(),
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::dynamic::framework::{HttpMethod, ParamSource};
+
+    fn parse_js(src: &[u8]) -> tree_sitter::Tree {
+        let mut parser = tree_sitter::Parser::new();
+        let lang = tree_sitter::Language::from(tree_sitter_javascript::LANGUAGE);
+        parser.set_language(&lang).unwrap();
+        parser.parse(src, None).unwrap()
+    }
+
+    fn summary(name: &str) -> FuncSummary {
+        FuncSummary {
+            name: name.into(),
+            lang: "javascript".into(),
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn fires_on_app_get_with_named_handler() {
+        let src: &[u8] = b"const express = require('express');\n\
+            const app = express();\n\
+            function getUser(req, res) { res.send(req.params.id); }\n\
+            app.get('/users/:id', getUser);\n";
+        let tree = parse_js(src);
+        let binding = JsExpressAdapter
+            .detect(&summary("getUser"), tree.root_node(), src)
+            .expect("binding");
+        assert_eq!(binding.adapter, "js-express");
+        assert_eq!(binding.kind, EntryKind::HttpRoute);
+        let route = binding.route.as_ref().unwrap();
+        assert_eq!(route.method, HttpMethod::GET);
+        assert_eq!(route.path, "/users/:id");
+        assert!(binding.request_params.iter().any(|p| p.name == "req"
+            && matches!(p.source, ParamSource::Implicit)));
+        assert!(binding.request_params.iter().any(|p| p.name == "res"
+            && matches!(p.source, ParamSource::Implicit)));
+    }
+
+    #[test]
+    fn fires_on_post_via_router_alias() {
+        let src: &[u8] = b"const express = require('express');\n\
+            const apiRouter = express.Router();\n\
+            function saveItem(req, res) { res.json(req.body); }\n\
+            apiRouter.post('/items', saveItem);\n";
+        let tree = parse_js(src);
+        let binding = JsExpressAdapter
+            .detect(&summary("saveItem"), tree.root_node(), src)
+            .expect("binding");
+        assert_eq!(binding.route.as_ref().unwrap().method, HttpMethod::POST);
+    }
+
+    #[test]
+    fn fires_on_middleware_chain() {
+        let src: &[u8] = b"const express = require('express');\n\
+            const app = express();\n\
+            function authz(req, res, next) { next(); }\n\
+            function handler(req, res) { res.send('ok'); }\n\
+            app.delete('/items/:id', authz, handler);\n";
+        let tree = parse_js(src);
+        let binding = JsExpressAdapter
+            .detect(&summary("handler"), tree.root_node(), src)
+            .expect("binding");
+        assert_eq!(binding.route.unwrap().method, HttpMethod::DELETE);
+    }
+
+    #[test]
+    fn skips_when_express_not_imported() {
+        let src: &[u8] = b"const koa = require('koa');\n\
+            const app = new koa();\n\
+            function handler(ctx) { ctx.body = 'ok'; }\n\
+            app.get('/x', handler);\n";
+        let tree = parse_js(src);
+        assert!(JsExpressAdapter
+            .detect(&summary("handler"), tree.root_node(), src)
+            .is_none());
+    }
+
+    #[test]
+    fn skips_when_handler_name_does_not_match() {
+        let src: &[u8] = b"const express = require('express');\n\
+            const app = express();\n\
+            function other(req, res) { res.send('x'); }\n\
+            app.get('/x', other);\n";
+        let tree = parse_js(src);
+        assert!(JsExpressAdapter
+            .detect(&summary("missing"), tree.root_node(), src)
+            .is_none());
+    }
+}