feat: Convert windows path to unix path before comparing against ModuleMatcher file_path value. (#40)

Author: bizob2828

README.md

@@ -139,7 +139,7 @@ type FunctionQuery =
 type ModuleMatcher = {
     name: string; // Module name
     versionRange: string; // Matching semver range
-    filePath: string; // Path to the file from the module root
+    filePath: string; // Relative Unix-style path to the file from the module root (e.g. "lib/index.js")
 };
 ```
 
@@ -177,7 +177,7 @@ matching instrumentation configurations.
 
 - `module_name` - Name of the module.
 - `version` - Version of the module.
-- `file_path` - Path to the file from the module root.
+- `file_path` - Relative Unix-style path to the file from the module root (e.g. `"lib/index.js"`). Windows-style backslash paths are also accepted and will be normalized automatically.
 
 ```ts
 free(): void;

src/config.rs

@@ -4,7 +4,7 @@
  **/
 use crate::function_query::FunctionQuery;
 use nodejs_semver::{Range, SemverError, Version};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 #[cfg_attr(feature = "wasm", derive(tsify::Tsify))]
 #[cfg_attr(
@@ -37,7 +37,7 @@ impl ModuleMatcher {
     }
 
     #[must_use]
-    pub fn matches(&self, module_name: &str, version: &str, file_path: &PathBuf) -> bool {
+    pub fn matches(&self, module_name: &str, version: &str, file_path: &Path) -> bool {
         let version: Version = match version.parse() {
             Ok(v) => v,
             Err(e) => {
@@ -46,9 +46,11 @@ impl ModuleMatcher {
             }
         };
 
+        // convert windows paths to unix before comparing against `self.file_path`
+        let normalized_path = PathBuf::from(file_path.to_string_lossy().replace('\\', "/"));
         self.name == module_name
             && version.satisfies(&self.version_range)
-            && self.file_path == *file_path
+            && self.file_path == normalized_path
     }
 }
 
@@ -120,7 +122,7 @@ impl Config {
 
 impl InstrumentationConfig {
     #[must_use]
-    pub fn matches(&self, module_name: &str, version: &str, file_path: &PathBuf) -> bool {
+    pub fn matches(&self, module_name: &str, version: &str, file_path: &Path) -> bool {
         self.module.matches(module_name, version, file_path)
     }
 }

src/instrumentation.rs

@@ -4,7 +4,7 @@
  **/
 use crate::config::InstrumentationConfig;
 use std::collections::HashMap;
-use std::path::PathBuf;
+use std::path::Path;
 use swc_core::common::{Span, SyntaxContext};
 use swc_core::ecma::{
     ast::{
@@ -244,7 +244,7 @@ impl Instrumentation {
     }
 
     #[must_use]
-    pub fn matches(&self, module_name: &str, version: &str, file_path: &PathBuf) -> bool {
+    pub fn matches(&self, module_name: &str, version: &str, file_path: &Path) -> bool {
         self.config.matches(module_name, version, file_path)
     }
 

src/lib.rs

@@ -18,7 +18,7 @@
  * 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 std::{collections::HashMap, error::Error, path::PathBuf, sync::Arc};
+use std::{collections::HashMap, error::Error, path::Path, path::PathBuf, sync::Arc};
 use swc::{
     config::{IsModule, SourceMapsConfig},
     sourcemap::SourceMap,
@@ -134,7 +134,7 @@ impl Instrumentor {
         &self,
         module_name: &str,
         version: &str,
-        file_path: &PathBuf,
+        file_path: &Path,
     ) -> InstrumentationVisitor {
         let instrumentations = self
             .instrumentations

tests/common/mod.rs

@@ -13,10 +13,18 @@ static TEST_MODULE_NAME: &str = "undici";
 static TEST_MODULE_PATH: &str = "index.mjs";
 
 pub fn transpile_and_test(test_file: &str, mjs: bool, config: Config) {
+    transpile_and_test_with_path(test_file, mjs, config, PathBuf::from(TEST_MODULE_PATH));
+}
+
+pub fn transpile_and_test_with_path(
+    test_file: &str,
+    mjs: bool,
+    config: Config,
+    file_path: PathBuf,
+) {
     let test_file = PathBuf::from(test_file);
     let test_dir = test_file.parent().expect("Couldn't find test directory");
 
-    let file_path = PathBuf::from("index.mjs");
     let instrumentor = Instrumentor::new(config);
     let mut instrumentations =
         instrumentor.get_matching_instrumentations(TEST_MODULE_NAME, "0.0.1", &file_path);
@@ -46,3 +54,9 @@ pub fn transpile_and_test(test_file: &str, mjs: bool, config: Config) {
 pub fn test_module_matcher() -> ModuleMatcher {
     ModuleMatcher::new(TEST_MODULE_NAME, ">=0.0.1", TEST_MODULE_PATH).unwrap()
 }
+
+static WINDOWS_TEST_MODULE_PATH: &str = "lib/index.mjs";
+
+pub fn windows_module_matcher() -> ModuleMatcher {
+    ModuleMatcher::new(TEST_MODULE_NAME, ">=0.0.1", WINDOWS_TEST_MODULE_PATH).unwrap()
+}

tests/instrumentor_test.rs

@@ -29,3 +29,4 @@ mod polyfill_mjs;
 mod private_method_cjs;
 mod var_class_export_alias_mjs;
 mod var_named_class_export_alias_mjs;
+mod windows_path;

tests/wasm/__snapshots__/tests.test.mjs.snap

@@ -287,3 +287,32 @@ export class Up {
   "map": "{"version":3,"file":"module.js","sources":["module.ts"],"sourceRoot":"","names":[],"mappings":";;;;;;AAEA,MAAM,CAAA,MAAO,EAAE;IACX,aAAA;;;;;;;;;YACI,OAAO,CAAC,GAAG,CAAC,aAAa,CAAC,CAAC;;;;;;;;;;;;;;;;IAC/B,CAAC;IACD,KAAK,IAAS,EAAA;;;mCAAR;gBACF,OAAO,CAAC,GAAG,CAAC,OAAO,CAAC,CAAC;YACzB,CAAC;;;;;;;;;;IACD,KAAK,CAAC,UAAU,GAAA;;;;;;;;;;;;IAAU,CAAC;IAC3B,GAAG,GAAA;;;;;;;;;;;;IAAU,CAAC;IACd,KAAK,EAAC,IAAK;;;;;;;;;;;;IAAU,CAAC;IACtB,KAAK,CAAC,IAAI,GAAA,CAAU,CAAC;CACxB"}",
 }
 `;
+
+exports[`windows style paths > should transform ESM module correctly 1`] = `
+{
+  "code": "import { tracingChannel as tr_ch_apm_tracingChannel } from "diagnostics_channel";
+const tr_ch_apm$up_fetch = tr_ch_apm_tracingChannel("orchestrion:one:up:fetch");
+export class Up {
+    constructor(){
+        console.log('constructor');
+    }
+    fetch() {
+        const __apm$original_args = arguments;
+        const __apm$traced = ()=>{
+            const __apm$wrapped = ()=>{
+                console.log('fetch');
+            };
+            return __apm$wrapped.apply(null, __apm$original_args);
+        };
+        if (!tr_ch_apm$up_fetch.hasSubscribers) return __apm$traced();
+        return tr_ch_apm$up_fetch.traceSync(__apm$traced, {
+            arguments,
+            self: this,
+            moduleVersion: "1.0.0"
+        });
+    }
+}
+",
+  "map": undefined,
+}
+`;

tests/wasm/tests.test.mjs

@@ -166,3 +166,42 @@ export class Up {
         }).toThrow('Failed to find injection points for: ["constructor", "fetch", "asyncFetch", "get", "send"]');
     });
 });
+
+describe('windows style paths', () => {
+    const instrumentor = create([
+        {
+            channelName: "up:fetch",
+            module: { name: "one", versionRange: ">=1", filePath: "path/to/file.js" },
+            functionQuery: {
+                className: "Up",
+                methodName: "fetch",
+                kind: "Sync",
+            },
+        },
+    ]);
+
+    const matchedTransforms = instrumentor.getTransformer(
+        "one",
+        "1.0.0",
+        "path\\to\\file.js",
+    );
+    
+  test('should get transformer for matching module', () => {
+        expect(matchedTransforms).toBeTruthy();
+    });
+
+    test('should transform ESM module correctly', () => {
+        const originalEsm = `export class Up {
+	constructor() {
+		console.log('constructor')
+	}
+
+	fetch() {
+		console.log('fetch')
+	}
+}`;
+
+        const output = matchedTransforms.transform(originalEsm, 'esm');
+        expect(output).toMatchSnapshot();
+    });
+})

tests/windows_path/mod.js

@@ -0,0 +1,9 @@
+/**
+ * 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.
+ **/
+async function fetch (url) {
+  return 42;
+}
+
+module.exports = { fetch };

tests/windows_path/mod.rs

@@ -0,0 +1,17 @@
+use crate::common::*;
+use orchestrion_js::*;
+use std::path::PathBuf;
+
+#[test]
+fn windows_path() {
+    transpile_and_test_with_path(
+        file!(),
+        false,
+        Config::new_single(InstrumentationConfig::new(
+            "fetch_decl",
+            windows_module_matcher(),
+            FunctionQuery::function_declaration("fetch", FunctionKind::Async),
+        )),
+        PathBuf::from("lib\\index.mjs"),
+    );
+}