fix: Don't check for matching sync/async function type

src/function_query.rs

@@ -2,7 +2,7 @@
  * Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
  * This product includes software developed at Datadog (<https://www.datadoghq.com>/). Copyright 2025 Datadog, Inc.
  **/
-use swc_core::ecma::ast::{FnDecl, FnExpr, Function};
+use swc_core::ecma::ast::FnDecl;
 
 #[derive(Debug, Clone)]
 pub(crate) enum FunctionType {
@@ -25,14 +25,6 @@ impl FunctionKind {
         matches!(self, FunctionKind::Async)
     }
 
-    #[must_use]
-    pub fn matches(&self, func: &Function) -> bool {
-        match self {
-            FunctionKind::Sync => !func.is_async && !func.is_generator,
-            FunctionKind::Async => func.is_async && !func.is_generator,
-        }
-    }
-
     #[must_use]
     pub fn tracing_operator(&self) -> &'static str {
         match self {
@@ -202,22 +194,19 @@ impl FunctionQuery {
 
     pub fn matches_decl(&self, func: &FnDecl, count: &mut usize) -> bool {
         let matches_except_count = matches!(self.typ(), FunctionType::FunctionDeclaration)
-            && self.kind().matches(&func.function)
             && func.ident.sym == self.name();
         self.maybe_increment_count(matches_except_count, count)
     }
 
-    pub fn matches_expr(&self, func: &FnExpr, count: &mut usize, name: &str) -> bool {
-        let matches_except_count = matches!(self.typ(), FunctionType::FunctionExpression)
-            && self.kind().matches(&func.function)
-            && name == self.name();
+    pub fn matches_expr(&self, count: &mut usize, name: &str) -> bool {
+        let matches_except_count =
+            matches!(self.typ(), FunctionType::FunctionExpression) && name == self.name();
         self.maybe_increment_count(matches_except_count, count)
     }
 
-    pub fn matches_method(&self, func: &Function, count: &mut usize, name: &str) -> bool {
-        let matches_except_count = matches!(self.typ(), FunctionType::Method)
-            && self.kind().matches(func)
-            && name == self.name();
+    pub fn matches_method(&self, count: &mut usize, name: &str) -> bool {
+        let matches_except_count =
+            matches!(self.typ(), FunctionType::Method) && name == self.name();
         self.maybe_increment_count(matches_except_count, count)
     }
 }

src/instrumentation.rs

@@ -166,7 +166,7 @@ impl Instrumentation {
         if self
             .config
             .function_query
-            .matches_expr(func_expr, &mut self.count, name.as_ref())
+            .matches_expr(&mut self.count, name.as_ref())
             && func_expr.function.body.is_some()
         {
             if let Some(body) = func_expr.function.body.as_mut() {
@@ -251,7 +251,7 @@ impl Instrumentation {
         if self
             .config
             .function_query
-            .matches_method(&node.function, &mut self.count, name.as_ref())
+            .matches_method(&mut self.count, name.as_ref())
             && node.function.body.is_some()
         {
             if let Some(body) = node.function.body.as_mut() {
@@ -284,7 +284,7 @@ impl Instrumentation {
         if self
             .config
             .function_query
-            .matches_method(&node.function, &mut self.count, name.as_ref())
+            .matches_method(&mut self.count, name.as_ref())
             && node.function.body.is_some()
         {
             if let Some(body) = node.function.body.as_mut() {

tests/decl_mjs_mismatched_type/mod.mjs

@@ -0,0 +1,10 @@
+
+/**
+ * Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+ * This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2025 Datadog, Inc.
+ **/
+function fetch (url) {
+  return Promise.resolve(42);
+}
+
+export { fetch };

tests/decl_mjs_mismatched_type/mod.rs

@@ -0,0 +1,15 @@
+use crate::common::*;
+use orchestrion_js::*;
+
+#[test]
+fn decl_mjs_mismatched_type() {
+    transpile_and_test(
+        file!(),
+        true,
+        Config::new_single(InstrumentationConfig::new(
+            "fetch_decl",
+            test_module_matcher(),
+            FunctionQuery::function_declaration("fetch", FunctionKind::Async),
+        )),
+    );
+}

tests/decl_mjs_mismatched_type/test.mjs

@@ -0,0 +1,15 @@
+/**
+ * Unless explicitly stated otherwise all files in this repository are licensed under the Apache-2.0 License.
+ * This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2025 Datadog, Inc.
+ **/
+import { fetch } from './instrumented.mjs';
+import { assert, getContext } from '../common/preamble.js';
+const context = getContext('orchestrion:undici:fetch_decl');
+const result = await fetch('https://example.com');
+assert.strictEqual(result, 42);
+assert.deepStrictEqual(context, {
+  start: true,
+  end: true,
+  asyncStart: 42,
+  asyncEnd: 42
+});

tests/instrumentor_test.rs

@@ -9,6 +9,7 @@ mod constructor_cjs;
 mod constructor_mjs;
 mod decl_cjs;
 mod decl_mjs;
+mod decl_mjs_mismatched_type;
 mod expr_cjs;
 mod expr_mjs;
 mod index_cjs;