fix: correct fix

Signed-off-by: sunrabbit123 <qudwls185@naver.com>

Author: sunrabbit123

src/client/cross-spawn.test.ts

@@ -72,10 +72,7 @@ describe("StdioClientTransport using cross-spawn", () => {
       "test-command",
       [],
       expect.objectContaining({
-        env: {
-          PATH: process.env.PATH,
-          ...customEnv,
-        }
+        env: customEnv
       })
     );
   });

src/client/stdio.test.ts

@@ -59,3 +59,33 @@ test("should read messages", async () => {
 
   await client.close();
 });
+
+test("should work with actual node mcp server", async () => {
+  const client = new StdioClientTransport({
+    command: "npx",
+    args: ["-y", "@wrtnlabs/calculator-mcp"],
+  });
+  
+  await client.start();
+  await client.close();
+});
+
+test("should work with actual node mcp server and empty env", async () => {
+  const client = new StdioClientTransport({
+    command: "npx",
+    args: ["-y", "@wrtnlabs/calculator-mcp"],
+    env: {},
+  });
+  await client.start();
+  await client.close();
+});
+
+test("should work with actual node mcp server and custom env", async () => {
+  const client = new StdioClientTransport({
+    command: "npx",
+    args: ["-y", "@wrtnlabs/calculator-mcp"],
+    env: {TEST_VAR: "test-value"},
+  });
+  await client.start();
+  await client.close();
+}); 

src/client/stdio.ts

@@ -113,13 +113,15 @@ export class StdioClientTransport implements Transport {
     }
 
     return new Promise((resolve, reject) => {
+      // const defaultEnv = getDefaultEnvironment();
       this._process = spawn(
         this._serverParams.command,
         this._serverParams.args ?? [],
         {
+          // merge default env with server env because mcp server needs some env vars
           env: {
-            PATH: process.env.PATH,
-            ...this._serverParams.env ?? getDefaultEnvironment(),
+            ...getDefaultEnvironment(),
+            ...this._serverParams.env,
           },
           stdio: ["pipe", "pipe", this._serverParams.stderr ?? "inherit"],
           shell: false,