From bf6f16c8be10c185e434e068c2a67f6d3baee6b7 Mon Sep 17 00:00:00 2001
From: Konstantin Konstantinov <KKonstantinov@users.noreply.github.com>
Date: Thu, 22 Jan 2026 14:26:48 +0200
Subject: [PATCH] eslint fixes in tests (#1418)

---
 .changeset/brave-lions-glow.md                |   2 +-
 .github/pages/index.html                      |  28 ++--
 common/eslint-config/eslint.config.mjs        |   7 +
 docs/documents.md                             |   8 +-
 ...ensions.test.ts => authExtensions.test.ts} |   0
 ...cross-spawn.test.ts => crossSpawn.test.ts} |   0
 .../client/test/client/middleware.test.ts     |   6 +-
 packages/client/test/client/sse.test.ts       |  59 ++++----
 .../client/test/client/streamableHttp.test.ts | 138 ++++++++++--------
 .../{in-memory.test.ts => inMemory.test.ts}   |  14 +-
 .../{auth-utils.test.ts => authUtils.test.ts} |   0
 ...t.ts => protocolTransportHandling.test.ts} |   0
 packages/core/test/shared/uriTemplate.test.ts |  11 +-
 packages/core/test/spec.types.test.ts         |   4 +-
 packages/core/test/types.test.ts              |   4 +-
 ...server-express.test.ts => express.test.ts} |   2 +-
 .../{server-hono.test.ts => hono.test.ts}     |   2 +-
 .../node/test/streamableHttp.test.ts          |  67 ++++-----
 .../server/test/server/streamableHttp.test.ts |  24 +--
 typedoc.config.mjs                            |  27 ++--
 20 files changed, 219 insertions(+), 184 deletions(-)
 rename packages/client/test/client/{auth-extensions.test.ts => authExtensions.test.ts} (100%)
 rename packages/client/test/client/{cross-spawn.test.ts => crossSpawn.test.ts} (100%)
 rename packages/core/test/experimental/{in-memory.test.ts => inMemory.test.ts} (99%)
 rename packages/core/test/shared/{auth-utils.test.ts => authUtils.test.ts} (100%)
 rename packages/core/test/shared/{protocol-transport-handling.test.ts => protocolTransportHandling.test.ts} (100%)
 rename packages/middleware/express/test/{server-express.test.ts => express.test.ts} (99%)
 rename packages/middleware/hono/test/{server-hono.test.ts => hono.test.ts} (99%)

diff --git a/.changeset/brave-lions-glow.md b/.changeset/brave-lions-glow.md
index 59a1f3a3..58718389 100644
--- a/.changeset/brave-lions-glow.md
+++ b/.changeset/brave-lions-glow.md
@@ -1,5 +1,5 @@
 ---
-"@modelcontextprotocol/node": patch
+'@modelcontextprotocol/node': patch
 ---
 
 Prevent Hono from overriding global Response object by passing `overrideGlobalObjects: false` to `getRequestListener()`. This fixes compatibility with frameworks like Next.js whose response classes extend the native Response.
diff --git a/.github/pages/index.html b/.github/pages/index.html
index 4dd2f3ba..5dd7adea 100644
--- a/.github/pages/index.html
+++ b/.github/pages/index.html
@@ -124,7 +124,7 @@
     </head>
     <body>
         <h1>MCP TypeScript SDK</h1>
-        
+
         <div class="redirect-notice">
             <p>Redirecting to <a href="{{ site.data.latest_version }}/">latest documentation ({{ site.data.latest_version }})</a>...</p>
         </div>
@@ -142,31 +142,39 @@
 
         <script>
             // Redirect to latest version
-            setTimeout(function() {
+            setTimeout(function () {
                 window.location.href = '{{ site.data.latest_version }}/';
             }, 1000);
 
             // Load and display package versions from versions.json
             fetch('{{ site.data.latest_version }}/versions.json')
-                .then(function(response) {
+                .then(function (response) {
                     if (!response.ok) throw new Error('versions.json not found');
                     return response.json();
                 })
-                .then(function(data) {
+                .then(function (data) {
                     var container = document.getElementById('package-versions');
                     var html = '<p>Packages included in the latest documentation:</p><ul class="package-list">';
-                    
+
                     for (var pkg in data.packages) {
-                        html += '<li><span class="package-name">' + pkg + '</span>: <span class="package-version">' + data.packages[pkg] + '</span></li>';
+                        html +=
+                            '<li><span class="package-name">' +
+                            pkg +
+                            '</span>: <span class="package-version">' +
+                            data.packages[pkg] +
+                            '</span></li>';
                     }
-                    
+
                     html += '</ul>';
-                    html += '<p style="font-size: 0.85rem; color: #666; margin-top: 1rem;">Generated from tag: ' + data.generated_from_tag + '</p>';
-                    
+                    html +=
+                        '<p style="font-size: 0.85rem; color: #666; margin-top: 1rem;">Generated from tag: ' +
+                        data.generated_from_tag +
+                        '</p>';
+
                     container.innerHTML = html;
                     container.classList.add('loaded');
                 })
-                .catch(function(err) {
+                .catch(function (err) {
                     // versions.json may not exist for older docs
                     document.getElementById('package-versions').style.display = 'none';
                 });
diff --git a/common/eslint-config/eslint.config.mjs b/common/eslint-config/eslint.config.mjs
index b55655e7..6e55630c 100644
--- a/common/eslint-config/eslint.config.mjs
+++ b/common/eslint-config/eslint.config.mjs
@@ -79,6 +79,13 @@ export default defineConfig(
             ]
         }
     },
+    {
+        // Disable consistent-function-scoping in test files where helper functions are common
+        files: ['**/*.test.ts', '**/*.test.tsx', '**/test/**'],
+        rules: {
+            'unicorn/consistent-function-scoping': 'off'
+        }
+    },
     {
         // Ignore generated protocol types everywhere
         ignores: ['**/spec.types.ts']
diff --git a/docs/documents.md b/docs/documents.md
index 5c12bfa4..36b8235c 100644
--- a/docs/documents.md
+++ b/docs/documents.md
@@ -1,10 +1,10 @@
 ---
 title: Documents
 children:
-  - ./server.md
-  - ./client.md
-  - ./capabilities.md
-  - ./faq.md
+    - ./server.md
+    - ./client.md
+    - ./capabilities.md
+    - ./faq.md
 ---
 
 # Documents
diff --git a/packages/client/test/client/auth-extensions.test.ts b/packages/client/test/client/authExtensions.test.ts
similarity index 100%
rename from packages/client/test/client/auth-extensions.test.ts
rename to packages/client/test/client/authExtensions.test.ts
diff --git a/packages/client/test/client/cross-spawn.test.ts b/packages/client/test/client/crossSpawn.test.ts
similarity index 100%
rename from packages/client/test/client/cross-spawn.test.ts
rename to packages/client/test/client/crossSpawn.test.ts
diff --git a/packages/client/test/client/middleware.test.ts b/packages/client/test/client/middleware.test.ts
index 45171542..64bbfa67 100644
--- a/packages/client/test/client/middleware.test.ts
+++ b/packages/client/test/client/middleware.test.ts
@@ -1018,9 +1018,9 @@ describe('createMiddleware', () => {
 
             if (response.headers.get('content-type')?.includes('application/json')) {
                 const data = (await response.json()) as Record<string, unknown>;
-                const transformed = { ...data, timestamp: 123456789 };
+                const transformed = { ...data, timestamp: 123_456_789 };
 
-                return new Response(JSON.stringify(transformed), {
+                return Response.json(transformed, {
                     status: response.status,
                     statusText: response.statusText,
                     headers: response.headers
@@ -1036,7 +1036,7 @@ describe('createMiddleware', () => {
 
         expect(result).toEqual({
             data: 'original',
-            timestamp: 123456789
+            timestamp: 123_456_789
         });
     });
 
diff --git a/packages/client/test/client/sse.test.ts b/packages/client/test/client/sse.test.ts
index 94e12c65..b08cb19f 100644
--- a/packages/client/test/client/sse.test.ts
+++ b/packages/client/test/client/sse.test.ts
@@ -300,9 +300,9 @@ describe('SSEClientTransport', () => {
 
             await transport.start();
 
-            const originalFetch = global.fetch;
+            const originalFetch = globalThis.fetch;
             try {
-                global.fetch = vi.fn().mockResolvedValue({ ok: true });
+                globalThis.fetch = vi.fn().mockResolvedValue({ ok: true });
 
                 const message: JSONRPCMessage = {
                     jsonrpc: '2.0',
@@ -313,7 +313,7 @@ describe('SSEClientTransport', () => {
 
                 await transport.send(message);
 
-                const calledHeaders = (global.fetch as Mock).mock.calls[0]![1].headers;
+                const calledHeaders = (globalThis.fetch as Mock).mock.calls[0]![1].headers;
                 expect(calledHeaders.get('Authorization')).toBe('Bearer test-token');
                 expect(calledHeaders.get('X-Custom-Header')).toBe('custom-value');
                 expect(calledHeaders.get('content-type')).toBe('application/json');
@@ -322,10 +322,10 @@ describe('SSEClientTransport', () => {
 
                 await transport.send(message);
 
-                const updatedHeaders = (global.fetch as Mock).mock.calls[1]![1].headers;
+                const updatedHeaders = (globalThis.fetch as Mock).mock.calls[1]![1].headers;
                 expect(updatedHeaders.get('X-Custom-Header')).toBe('updated-value');
             } finally {
-                global.fetch = originalFetch;
+                globalThis.fetch = originalFetch;
             }
         });
 
@@ -343,9 +343,9 @@ describe('SSEClientTransport', () => {
 
             await transport.start();
 
-            const originalFetch = global.fetch;
+            const originalFetch = globalThis.fetch;
             try {
-                global.fetch = vi.fn().mockResolvedValue({ ok: true });
+                globalThis.fetch = vi.fn().mockResolvedValue({ ok: true });
 
                 const message: JSONRPCMessage = {
                     jsonrpc: '2.0',
@@ -356,7 +356,7 @@ describe('SSEClientTransport', () => {
 
                 await transport.send(message);
 
-                const calledHeaders = (global.fetch as Mock).mock.calls[0]![1].headers;
+                const calledHeaders = (globalThis.fetch as Mock).mock.calls[0]![1].headers;
                 expect(calledHeaders.get('Authorization')).toBe('Bearer test-token');
                 expect(calledHeaders.get('X-Custom-Header')).toBe('custom-value');
                 expect(calledHeaders.get('content-type')).toBe('application/json');
@@ -365,10 +365,10 @@ describe('SSEClientTransport', () => {
 
                 await transport.send(message);
 
-                const updatedHeaders = (global.fetch as Mock).mock.calls[1]![1].headers;
+                const updatedHeaders = (globalThis.fetch as Mock).mock.calls[1]![1].headers;
                 expect(updatedHeaders.get('X-Custom-Header')).toBe('updated-value');
             } finally {
-                global.fetch = originalFetch;
+                globalThis.fetch = originalFetch;
             }
         });
 
@@ -384,24 +384,24 @@ describe('SSEClientTransport', () => {
 
             await transport.start();
 
-            const originalFetch = global.fetch;
+            const originalFetch = globalThis.fetch;
             try {
-                global.fetch = vi.fn().mockResolvedValue({ ok: true });
+                globalThis.fetch = vi.fn().mockResolvedValue({ ok: true });
 
                 await transport.send({ jsonrpc: '2.0', id: '1', method: 'test', params: {} });
 
-                const calledHeaders = (global.fetch as Mock).mock.calls[0]![1].headers;
+                const calledHeaders = (globalThis.fetch as Mock).mock.calls[0]![1].headers;
                 expect(calledHeaders.get('Authorization')).toBe('Bearer test-token');
                 expect(calledHeaders.get('X-Custom-Header')).toBe('custom-value');
                 expect(calledHeaders.get('content-type')).toBe('application/json');
             } finally {
-                global.fetch = originalFetch;
+                globalThis.fetch = originalFetch;
             }
         });
     });
 
     describe('auth handling', () => {
-        const authServerMetadataUrls = ['/.well-known/oauth-authorization-server', '/.well-known/openid-configuration'];
+        const authServerMetadataUrls = new Set(['/.well-known/oauth-authorization-server', '/.well-known/openid-configuration']);
 
         let mockAuthProvider: Mocked<OAuthClientProvider>;
 
@@ -516,10 +516,10 @@ describe('SSEClientTransport', () => {
                     return;
                 }
 
-                if (req.url !== '/') {
-                    res.writeHead(404).end();
-                } else {
+                if (req.url === '/') {
                     res.writeHead(401).end();
+                } else {
+                    res.writeHead(404).end();
                 }
             });
 
@@ -550,7 +550,7 @@ describe('SSEClientTransport', () => {
                 lastServerRequest = req;
 
                 switch (req.method) {
-                    case 'GET':
+                    case 'GET': {
                         if (req.url === '/.well-known/oauth-protected-resource') {
                             res.writeHead(200, {
                                 'Content-Type': 'application/json'
@@ -576,11 +576,13 @@ describe('SSEClientTransport', () => {
                         res.write('event: endpoint\n');
                         res.write(`data: ${resourceBaseUrl.href}\n\n`);
                         break;
+                    }
 
-                    case 'POST':
+                    case 'POST': {
                         res.writeHead(401);
                         res.end();
                         break;
+                    }
                 }
             });
 
@@ -658,7 +660,7 @@ describe('SSEClientTransport', () => {
             authServer.close();
 
             authServer = createServer((req, res) => {
-                if (req.url && authServerMetadataUrls.includes(req.url)) {
+                if (req.url && authServerMetadataUrls.has(req.url)) {
                     res.writeHead(404).end();
                     return;
                 }
@@ -786,7 +788,7 @@ describe('SSEClientTransport', () => {
             authServer.close();
 
             authServer = createServer((req, res) => {
-                if (req.url && authServerMetadataUrls.includes(req.url)) {
+                if (req.url && authServerMetadataUrls.has(req.url)) {
                     res.writeHead(404).end();
                     return;
                 }
@@ -849,7 +851,7 @@ describe('SSEClientTransport', () => {
                 }
 
                 switch (req.method) {
-                    case 'GET':
+                    case 'GET': {
                         if (req.url !== '/') {
                             res.writeHead(404).end();
                             return;
@@ -863,6 +865,7 @@ describe('SSEClientTransport', () => {
                         res.write('event: endpoint\n');
                         res.write(`data: ${resourceBaseUrl.href}\n\n`);
                         break;
+                    }
 
                     case 'POST': {
                         if (req.url !== '/') {
@@ -937,7 +940,7 @@ describe('SSEClientTransport', () => {
             authServer.close();
 
             authServer = createServer((req, res) => {
-                if (req.url && authServerMetadataUrls.includes(req.url)) {
+                if (req.url && authServerMetadataUrls.has(req.url)) {
                     res.writeHead(404).end();
                     return;
                 }
@@ -1309,7 +1312,7 @@ describe('SSEClientTransport', () => {
             });
 
             // Spy on global fetch to detect unauthorized usage
-            globalFetchSpy = vi.spyOn(global, 'fetch');
+            globalFetchSpy = vi.spyOn(globalThis, 'fetch');
 
             // Create mock auth provider with default configuration
             mockAuthProvider = createMockAuthProvider({
@@ -1386,7 +1389,7 @@ describe('SSEClientTransport', () => {
             // Set up resource server that accepts SSE connection but returns 401 on POST
             resourceServerHandler.mockImplementation((req: IncomingMessage, res: ServerResponse) => {
                 switch (req.method) {
-                    case 'GET':
+                    case 'GET': {
                         if (req.url === '/') {
                             // Accept SSE connection
                             res.writeHead(200, {
@@ -1399,8 +1402,9 @@ describe('SSEClientTransport', () => {
                             return;
                         }
                         break;
+                    }
 
-                    case 'POST':
+                    case 'POST': {
                         if (req.url === '/') {
                             // Return 401 to trigger auth retry
                             res.writeHead(401, {
@@ -1410,6 +1414,7 @@ describe('SSEClientTransport', () => {
                             return;
                         }
                         break;
+                    }
                 }
 
                 res.writeHead(404).end();
diff --git a/packages/client/test/client/streamableHttp.test.ts b/packages/client/test/client/streamableHttp.test.ts
index 0c5d2dc0..13d746ca 100644
--- a/packages/client/test/client/streamableHttp.test.ts
+++ b/packages/client/test/client/streamableHttp.test.ts
@@ -1,6 +1,6 @@
 import type { JSONRPCMessage, JSONRPCRequest } from '@modelcontextprotocol/core';
 import { InvalidClientError, InvalidGrantError, UnauthorizedClientError } from '@modelcontextprotocol/core';
-import { type Mock, type Mocked } from 'vitest';
+import type { Mock, Mocked } from 'vitest';
 
 import type { OAuthClientProvider } from '../../src/client/auth.js';
 import { UnauthorizedError } from '../../src/client/auth.js';
@@ -28,7 +28,7 @@ describe('StreamableHTTPClientTransport', () => {
             invalidateCredentials: vi.fn()
         };
         transport = new StreamableHTTPClientTransport(new URL('http://localhost:1234/mcp'), { authProvider: mockAuthProvider });
-        vi.spyOn(global, 'fetch');
+        vi.spyOn(globalThis, 'fetch');
     });
 
     afterEach(async () => {
@@ -44,7 +44,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'test-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 202,
             headers: new Headers()
@@ -52,7 +52,7 @@ describe('StreamableHTTPClientTransport', () => {
 
         await transport.send(message);
 
-        expect(global.fetch).toHaveBeenCalledWith(
+        expect(globalThis.fetch).toHaveBeenCalledWith(
             expect.anything(),
             expect.objectContaining({
                 method: 'POST',
@@ -68,7 +68,7 @@ describe('StreamableHTTPClientTransport', () => {
             { jsonrpc: '2.0', method: 'test2', params: {}, id: 'id2' }
         ];
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/event-stream' }),
@@ -77,7 +77,7 @@ describe('StreamableHTTPClientTransport', () => {
 
         await transport.send(messages);
 
-        expect(global.fetch).toHaveBeenCalledWith(
+        expect(globalThis.fetch).toHaveBeenCalledWith(
             expect.anything(),
             expect.objectContaining({
                 method: 'POST',
@@ -98,7 +98,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'init-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/event-stream', 'mcp-session-id': 'test-session-id' })
@@ -107,7 +107,7 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.send(message);
 
         // Send a second message that should include the session ID
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 202,
             headers: new Headers()
@@ -116,8 +116,8 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.send({ jsonrpc: '2.0', method: 'test', params: {} } as JSONRPCMessage);
 
         // Check that second request included session ID header
-        const calls = (global.fetch as Mock).mock.calls;
-        const lastCall = calls[calls.length - 1]!;
+        const calls = (globalThis.fetch as Mock).mock.calls;
+        const lastCall = calls.at(-1)!;
         expect(lastCall[1].headers).toBeDefined();
         expect(lastCall[1].headers.get('mcp-session-id')).toBe('test-session-id');
     });
@@ -134,7 +134,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'init-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/event-stream', 'mcp-session-id': 'test-session-id' })
@@ -144,7 +144,7 @@ describe('StreamableHTTPClientTransport', () => {
         expect(transport.sessionId).toBe('test-session-id');
 
         // Now terminate the session
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers()
@@ -153,8 +153,8 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.terminateSession();
 
         // Verify the DELETE request was sent with the session ID
-        const calls = (global.fetch as Mock).mock.calls;
-        const lastCall = calls[calls.length - 1]!;
+        const calls = (globalThis.fetch as Mock).mock.calls;
+        const lastCall = calls.at(-1)!;
         expect(lastCall[1].method).toBe('DELETE');
         expect(lastCall[1].headers.get('mcp-session-id')).toBe('test-session-id');
 
@@ -174,7 +174,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'init-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/event-stream', 'mcp-session-id': 'test-session-id' })
@@ -183,7 +183,7 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.send(message);
 
         // Now terminate the session, but server responds with 405
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: false,
             status: 405,
             statusText: 'Method Not Allowed',
@@ -201,7 +201,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'test-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: false,
             status: 404,
             statusText: 'Not Found',
@@ -230,7 +230,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'test-id'
         };
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'application/json' }),
@@ -247,7 +247,7 @@ describe('StreamableHTTPClientTransport', () => {
 
     it('should attempt initial GET connection and handle 405 gracefully', async () => {
         // Mock the server not supporting GET for SSE (returning 405)
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: false,
             status: 405,
             statusText: 'Method Not Allowed'
@@ -258,7 +258,7 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.start();
         await expect(transport['_startOrAuthSse']({})).resolves.not.toThrow('Failed to open SSE stream: Method Not Allowed');
         // Check that GET was attempted
-        expect(global.fetch).toHaveBeenCalledWith(
+        expect(globalThis.fetch).toHaveBeenCalledWith(
             expect.anything(),
             expect.objectContaining({
                 method: 'GET',
@@ -267,14 +267,14 @@ describe('StreamableHTTPClientTransport', () => {
         );
 
         // Verify transport still works after 405
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 202,
             headers: new Headers()
         });
 
         await transport.send({ jsonrpc: '2.0', method: 'test', params: {} } as JSONRPCMessage);
-        expect(global.fetch).toHaveBeenCalledTimes(2);
+        expect(globalThis.fetch).toHaveBeenCalledTimes(2);
     });
 
     it('should handle successful initial GET connection for SSE', async () => {
@@ -289,7 +289,7 @@ describe('StreamableHTTPClientTransport', () => {
         });
 
         // Mock successful GET connection
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/event-stream' }),
@@ -326,7 +326,7 @@ describe('StreamableHTTPClientTransport', () => {
             });
         };
 
-        (global.fetch as Mock)
+        (globalThis.fetch as Mock)
             .mockResolvedValueOnce({
                 ok: true,
                 status: 200,
@@ -376,7 +376,7 @@ describe('StreamableHTTPClientTransport', () => {
         transport = new StreamableHTTPClientTransport(new URL('http://localhost:1234/mcp'), {
             reconnectionOptions: {
                 initialReconnectionDelay: 500,
-                maxReconnectionDelay: 10000,
+                maxReconnectionDelay: 10_000,
                 reconnectionDelayGrowFactor: 2,
                 maxRetries: 5
             }
@@ -396,7 +396,7 @@ describe('StreamableHTTPClientTransport', () => {
         transport = new StreamableHTTPClientTransport(new URL('http://localhost:1234/mcp'));
 
         // Mock fetch to verify headers sent
-        const fetchSpy = global.fetch as Mock;
+        const fetchSpy = globalThis.fetch as Mock;
         fetchSpy.mockReset();
         fetchSpy.mockResolvedValue({
             ok: true,
@@ -444,7 +444,7 @@ describe('StreamableHTTPClientTransport', () => {
         const errorSpy = vi.fn();
         transport.onerror = errorSpy;
 
-        (global.fetch as Mock).mockResolvedValueOnce({
+        (globalThis.fetch as Mock).mockResolvedValueOnce({
             ok: true,
             status: 200,
             headers: new Headers({ 'content-type': 'text/plain' }),
@@ -477,7 +477,7 @@ describe('StreamableHTTPClientTransport', () => {
         expect(customFetch).toHaveBeenCalled();
 
         // Global fetch should never have been called
-        expect(global.fetch).not.toHaveBeenCalled();
+        expect(globalThis.fetch).not.toHaveBeenCalled();
     });
 
     it('should always send specified custom headers', async () => {
@@ -493,7 +493,7 @@ describe('StreamableHTTPClientTransport', () => {
 
         let actualReqInit: RequestInit = {};
 
-        (global.fetch as Mock).mockImplementation(async (_url, reqInit) => {
+        (globalThis.fetch as Mock).mockImplementation(async (_url, reqInit) => {
             actualReqInit = reqInit;
             return new Response(null, { status: 200, headers: { 'content-type': 'text/event-stream' } });
         });
@@ -509,7 +509,7 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.send({ jsonrpc: '2.0', method: 'test', params: {} } as JSONRPCMessage);
         expect((actualReqInit.headers as Headers).get('x-custom-header')).toBe('SecondCustomValue');
 
-        expect(global.fetch).toHaveBeenCalledTimes(2);
+        expect(globalThis.fetch).toHaveBeenCalledTimes(2);
     });
 
     it('should always send specified custom headers (Headers class)', async () => {
@@ -525,7 +525,7 @@ describe('StreamableHTTPClientTransport', () => {
 
         let actualReqInit: RequestInit = {};
 
-        (global.fetch as Mock).mockImplementation(async (_url, reqInit) => {
+        (globalThis.fetch as Mock).mockImplementation(async (_url, reqInit) => {
             actualReqInit = reqInit;
             return new Response(null, { status: 200, headers: { 'content-type': 'text/event-stream' } });
         });
@@ -541,7 +541,7 @@ describe('StreamableHTTPClientTransport', () => {
         await transport.send({ jsonrpc: '2.0', method: 'test', params: {} } as JSONRPCMessage);
         expect((actualReqInit.headers as Headers).get('x-custom-header')).toBe('SecondCustomValue');
 
-        expect(global.fetch).toHaveBeenCalledTimes(2);
+        expect(globalThis.fetch).toHaveBeenCalledTimes(2);
     });
 
     it('should always send specified custom headers (array of tuples)', async () => {
@@ -556,7 +556,7 @@ describe('StreamableHTTPClientTransport', () => {
 
         let actualReqInit: RequestInit = {};
 
-        (global.fetch as Mock).mockImplementation(async (_url, reqInit) => {
+        (globalThis.fetch as Mock).mockImplementation(async (_url, reqInit) => {
             actualReqInit = reqInit;
             return new Response(null, { status: 200, headers: { 'content-type': 'text/event-stream' } });
         });
@@ -608,18 +608,22 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'test-id'
         };
 
-        (global.fetch as Mock)
+        (globalThis.fetch as Mock)
             .mockResolvedValueOnce({
                 ok: false,
                 status: 401,
                 statusText: 'Unauthorized',
                 headers: new Headers(),
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             })
             .mockResolvedValue({
                 ok: false,
                 status: 404,
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             });
 
         await expect(transport.send(message)).rejects.toThrow(UnauthorizedError);
@@ -634,7 +638,7 @@ describe('StreamableHTTPClientTransport', () => {
             id: 'test-id'
         };
 
-        const fetchMock = global.fetch as Mock;
+        const fetchMock = globalThis.fetch as Mock;
         fetchMock
             // First call: returns 403 with insufficient_scope
             .mockResolvedValueOnce({
@@ -685,7 +689,7 @@ describe('StreamableHTTPClientTransport', () => {
         };
 
         // Mock fetch calls to always return 403 with insufficient_scope
-        const fetchMock = global.fetch as Mock;
+        const fetchMock = globalThis.fetch as Mock;
         fetchMock.mockResolvedValue({
             ok: false,
             status: 403,
@@ -745,7 +749,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             // Mock the initial GET request, which will fail.
             fetchMock.mockResolvedValueOnce({
                 ok: true,
@@ -799,7 +803,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             // Mock the POST request. It returns a streaming content-type but a failing body.
             fetchMock.mockResolvedValueOnce({
                 ok: true,
@@ -854,7 +858,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             // First call: POST returns streaming response with priming event
             fetchMock.mockResolvedValueOnce({
                 ok: true,
@@ -917,7 +921,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             fetchMock.mockResolvedValueOnce({
                 ok: true,
                 status: 200,
@@ -966,7 +970,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
 
             // POST request returns streaming response
             fetchMock.mockResolvedValueOnce({
@@ -1016,7 +1020,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             fetchMock.mockResolvedValueOnce({
                 ok: true,
                 status: 200,
@@ -1065,9 +1069,11 @@ describe('StreamableHTTPClientTransport', () => {
             status: 401,
             statusText: 'Unauthorized',
             headers: new Headers(),
-            text: async () => Promise.reject('dont read my body')
+            text: async () => {
+                throw 'dont read my body';
+            }
         };
-        (global.fetch as Mock)
+        (globalThis.fetch as Mock)
             // Initial connection
             .mockResolvedValueOnce(unauthedResponse)
             // Resource discovery, path aware
@@ -1120,9 +1126,11 @@ describe('StreamableHTTPClientTransport', () => {
             status: 401,
             statusText: 'Unauthorized',
             headers: new Headers(),
-            text: async () => Promise.reject('dont read my body')
+            text: async () => {
+                throw 'dont read my body';
+            }
         };
-        (global.fetch as Mock)
+        (globalThis.fetch as Mock)
             // Initial connection
             .mockResolvedValueOnce(unauthedResponse)
             // Resource discovery, path aware
@@ -1147,7 +1155,9 @@ describe('StreamableHTTPClientTransport', () => {
             .mockResolvedValue({
                 ok: false,
                 status: 404,
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             });
 
         // As above, just ensure the auth flow completes without unhandled
@@ -1174,9 +1184,11 @@ describe('StreamableHTTPClientTransport', () => {
             status: 401,
             statusText: 'Unauthorized',
             headers: new Headers(),
-            text: async () => Promise.reject('dont read my body')
+            text: async () => {
+                throw 'dont read my body';
+            }
         };
-        (global.fetch as Mock)
+        (globalThis.fetch as Mock)
             // Initial connection
             .mockResolvedValueOnce(unauthedResponse)
             // Resource discovery, path aware
@@ -1201,7 +1213,9 @@ describe('StreamableHTTPClientTransport', () => {
             .mockResolvedValue({
                 ok: false,
                 status: 404,
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             });
 
         // Behavior for InvalidGrantError during auth is covered in dedicated OAuth
@@ -1217,7 +1231,9 @@ describe('StreamableHTTPClientTransport', () => {
                 status: 401,
                 statusText: 'Unauthorized',
                 headers: new Headers(),
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             };
 
             // Create custom fetch
@@ -1278,7 +1294,7 @@ describe('StreamableHTTPClientTransport', () => {
             expect(mockAuthProvider.redirectToAuthorization).toHaveBeenCalled();
 
             // Global fetch should never have been called
-            expect(global.fetch).not.toHaveBeenCalled();
+            expect(globalThis.fetch).not.toHaveBeenCalled();
         });
 
         it('uses custom fetch in finishAuth method - no global fetch fallback', async () => {
@@ -1353,14 +1369,14 @@ describe('StreamableHTTPClientTransport', () => {
             });
 
             // Global fetch should never have been called
-            expect(global.fetch).not.toHaveBeenCalled();
+            expect(globalThis.fetch).not.toHaveBeenCalled();
         });
     });
 
     describe('SSE retry field handling', () => {
         beforeEach(() => {
             vi.useFakeTimers();
-            (global.fetch as Mock).mockReset();
+            (globalThis.fetch as Mock).mockReset();
         });
         afterEach(() => vi.useRealTimers());
 
@@ -1387,7 +1403,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             fetchMock.mockResolvedValueOnce({
                 ok: true,
                 status: 200,
@@ -1463,7 +1479,7 @@ describe('StreamableHTTPClientTransport', () => {
                 }
             });
 
-            const fetchMock = global.fetch as Mock;
+            const fetchMock = globalThis.fetch as Mock;
             fetchMock.mockResolvedValueOnce({
                 ok: true,
                 status: 200,
@@ -1582,10 +1598,12 @@ describe('StreamableHTTPClientTransport', () => {
                 status: 401,
                 statusText: 'Unauthorized',
                 headers: new Headers(),
-                text: async () => Promise.reject('dont read my body')
+                text: async () => {
+                    throw 'dont read my body';
+                }
             };
 
-            (global.fetch as Mock)
+            (globalThis.fetch as Mock)
                 // First request - 401, triggers auth flow
                 .mockResolvedValueOnce(unauthedResponse)
                 // Resource discovery, path aware
diff --git a/packages/core/test/experimental/in-memory.test.ts b/packages/core/test/experimental/inMemory.test.ts
similarity index 99%
rename from packages/core/test/experimental/in-memory.test.ts
rename to packages/core/test/experimental/inMemory.test.ts
index 30e36a10..65e0a99a 100644
--- a/packages/core/test/experimental/in-memory.test.ts
+++ b/packages/core/test/experimental/inMemory.test.ts
@@ -18,7 +18,7 @@ describe('InMemoryTaskStore', () => {
     describe('createTask', () => {
         it('should create a new task with working status', async () => {
             const taskParams: TaskCreationParams = {
-                ttl: 60000
+                ttl: 60_000
             };
             const request: Request = {
                 method: 'tools/call',
@@ -32,7 +32,7 @@ describe('InMemoryTaskStore', () => {
             expect(typeof task.taskId).toBe('string');
             expect(task.taskId.length).toBeGreaterThan(0);
             expect(task.status).toBe('working');
-            expect(task.ttl).toBe(60000);
+            expect(task.ttl).toBe(60_000);
             expect(task.pollInterval).toBeDefined();
             expect(task.createdAt).toBeDefined();
             expect(new Date(task.createdAt).getTime()).toBeGreaterThan(0);
@@ -221,7 +221,7 @@ describe('InMemoryTaskStore', () => {
 
         beforeEach(async () => {
             const taskParams: TaskCreationParams = {
-                ttl: 60000
+                ttl: 60_000
             };
             const createdTask = await store.createTask(taskParams, 333, {
                 method: 'tools/call',
@@ -423,7 +423,7 @@ describe('InMemoryTaskStore', () => {
             });
 
             // Fast-forward a long time
-            vi.advanceTimersByTime(100000);
+            vi.advanceTimersByTime(100_000);
 
             // Task should still exist
             const task = await store.getTask(createdTask.taskId);
@@ -502,7 +502,7 @@ describe('InMemoryTaskStore', () => {
             expect(createdTask.ttl).toBeNull();
 
             // Task should not be cleaned up even after a long time
-            vi.advanceTimersByTime(100000);
+            vi.advanceTimersByTime(100_000);
             const task = await store.getTask(createdTask.taskId);
             expect(task).toBeDefined();
             expect(task?.taskId).toBe(createdTask.taskId);
@@ -639,7 +639,7 @@ describe('InMemoryTaskStore', () => {
             }
 
             // Get first 3 tasks
-            const allTaskIds = Array.from(store.getAllTasks().map(t => t.taskId));
+            const allTaskIds = store.getAllTasks().map(t => t.taskId);
             const result = await store.listTasks(allTaskIds[2]);
 
             // Should get tasks after the third task
@@ -920,7 +920,7 @@ describe('InMemoryTaskMessageQueue', () => {
                     jsonrpc: '2.0',
                     id: 1,
                     error: {
-                        code: -32600,
+                        code: -32_600,
                         message: 'Invalid Request'
                     }
                 },
diff --git a/packages/core/test/shared/auth-utils.test.ts b/packages/core/test/shared/authUtils.test.ts
similarity index 100%
rename from packages/core/test/shared/auth-utils.test.ts
rename to packages/core/test/shared/authUtils.test.ts
diff --git a/packages/core/test/shared/protocol-transport-handling.test.ts b/packages/core/test/shared/protocolTransportHandling.test.ts
similarity index 100%
rename from packages/core/test/shared/protocol-transport-handling.test.ts
rename to packages/core/test/shared/protocolTransportHandling.test.ts
diff --git a/packages/core/test/shared/uriTemplate.test.ts b/packages/core/test/shared/uriTemplate.test.ts
index 5bd54d2c..3954901c 100644
--- a/packages/core/test/shared/uriTemplate.test.ts
+++ b/packages/core/test/shared/uriTemplate.test.ts
@@ -200,7 +200,7 @@ describe('UriTemplate', () => {
 
     describe('security and edge cases', () => {
         it('should handle extremely long input strings', () => {
-            const longString = 'x'.repeat(100000);
+            const longString = 'x'.repeat(100_000);
             const template = new UriTemplate(`/api/{param}`);
             expect(template.expand({ param: longString })).toBe(`/api/${longString}`);
             expect(template.match(`/api/${longString}`)).toEqual({ param: longString });
@@ -234,7 +234,7 @@ describe('UriTemplate', () => {
         it('should handle pathological regex patterns', () => {
             const template = new UriTemplate('/api/{param}');
             // Create a string that could cause catastrophic backtracking
-            const input = '/api/' + 'a'.repeat(100000);
+            const input = '/api/' + 'a'.repeat(100_000);
             expect(() => template.match(input)).not.toThrow();
         });
 
@@ -273,15 +273,14 @@ describe('UriTemplate', () => {
 
         it('should handle maximum template expression limit', () => {
             // Create a template with many expressions
-            const expressions = Array(10000).fill('{param}').join('');
+            const expressions = Array.from({ length: 10_000 }).fill('{param}').join('');
             expect(() => new UriTemplate(expressions)).not.toThrow();
         });
 
         it('should handle maximum variable name length', () => {
-            const longName = 'a'.repeat(10000);
+            const longName = 'a'.repeat(10_000);
             const template = new UriTemplate(`{${longName}}`);
-            const vars: Record<string, string> = {};
-            vars[longName] = 'value';
+            const vars: Record<string, string> = { [longName]: 'value' };
             expect(() => template.expand(vars)).not.toThrow();
         });
 
diff --git a/packages/core/test/spec.types.test.ts b/packages/core/test/spec.types.test.ts
index f7f99fe2..8ec29b09 100644
--- a/packages/core/test/spec.types.test.ts
+++ b/packages/core/test/spec.types.test.ts
@@ -707,8 +707,8 @@ function extractExportedTypes(source: string): string[] {
 }
 
 describe('Spec Types', () => {
-    const specTypes = extractExportedTypes(fs.readFileSync(SPEC_TYPES_FILE, 'utf-8'));
-    const sdkTypes = extractExportedTypes(fs.readFileSync(SDK_TYPES_FILE, 'utf-8'));
+    const specTypes = extractExportedTypes(fs.readFileSync(SPEC_TYPES_FILE, 'utf8'));
+    const sdkTypes = extractExportedTypes(fs.readFileSync(SDK_TYPES_FILE, 'utf8'));
     const typesToCheck = specTypes.filter(type => !MISSING_SDK_TYPES.includes(type));
 
     it('should define some expected types', () => {
diff --git a/packages/core/test/types.test.ts b/packages/core/test/types.test.ts
index c14fe406..8798c496 100644
--- a/packages/core/test/types.test.ts
+++ b/packages/core/test/types.test.ts
@@ -912,7 +912,7 @@ describe('Types', () => {
         test('should validate all new stop reasons', () => {
             const stopReasons = ['endTurn', 'stopSequence', 'maxTokens', 'toolUse', 'refusal', 'other'];
 
-            stopReasons.forEach(stopReason => {
+            for (const stopReason of stopReasons) {
                 const result = {
                     model: 'test',
                     role: 'assistant',
@@ -922,7 +922,7 @@ describe('Types', () => {
 
                 const parseResult = CreateMessageResultSchema.safeParse(result);
                 expect(parseResult.success).toBe(true);
-            });
+            }
         });
 
         test('should allow custom stop reason string', () => {
diff --git a/packages/middleware/express/test/server-express.test.ts b/packages/middleware/express/test/express.test.ts
similarity index 99%
rename from packages/middleware/express/test/server-express.test.ts
rename to packages/middleware/express/test/express.test.ts
index 528cbbf1..64cf533b 100644
--- a/packages/middleware/express/test/server-express.test.ts
+++ b/packages/middleware/express/test/express.test.ts
@@ -35,7 +35,7 @@ describe('@modelcontextprotocol/express', () => {
                 expect.objectContaining({
                     jsonrpc: '2.0',
                     error: expect.objectContaining({
-                        code: -32000
+                        code: -32_000
                     }),
                     id: null
                 })
diff --git a/packages/middleware/hono/test/server-hono.test.ts b/packages/middleware/hono/test/hono.test.ts
similarity index 99%
rename from packages/middleware/hono/test/server-hono.test.ts
rename to packages/middleware/hono/test/hono.test.ts
index c9d14634..a080f1ff 100644
--- a/packages/middleware/hono/test/server-hono.test.ts
+++ b/packages/middleware/hono/test/hono.test.ts
@@ -17,7 +17,7 @@ describe('@modelcontextprotocol/hono', () => {
             expect.objectContaining({
                 jsonrpc: '2.0',
                 error: expect.objectContaining({
-                    code: -32000
+                    code: -32_000
                 }),
                 id: null
             })
diff --git a/packages/middleware/node/test/streamableHttp.test.ts b/packages/middleware/node/test/streamableHttp.test.ts
index 65f74d17..406194a2 100644
--- a/packages/middleware/node/test/streamableHttp.test.ts
+++ b/packages/middleware/node/test/streamableHttp.test.ts
@@ -26,7 +26,7 @@ async function getFreePort() {
         srv.listen(0, () => {
             const address = srv.address()!;
             if (typeof address === 'string') {
-                throw new Error('Unexpected address type: ' + typeof address);
+                throw new TypeError('Unexpected address type: ' + typeof address);
             }
             const port = (address as AddressInfo).port;
             srv.close(_err => res(port));
@@ -152,12 +152,13 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
     /**
      * Helper to create and start test HTTP server with MCP setup
      */
-    async function createTestServer(config: TestServerConfig = { sessionIdGenerator: () => randomUUID() }): Promise<{
+    async function createTestServer(config?: TestServerConfig): Promise<{
         server: Server;
         transport: NodeStreamableHTTPServerTransport;
         mcpServer: McpServer;
         baseUrl: URL;
     }> {
+        config ??= { sessionIdGenerator: () => randomUUID() };
         const mcpServer = new McpServer({ name: 'test-server', version: '1.0.0' }, { capabilities: { logging: {} } });
 
         mcpServer.tool(
@@ -182,11 +183,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
         const server = createServer(async (req, res) => {
             try {
-                if (config.customRequestHandler) {
-                    await config.customRequestHandler(req, res);
-                } else {
-                    await transport.handleRequest(req, res);
-                }
+                await (config.customRequestHandler ? config.customRequestHandler(req, res) : transport.handleRequest(req, res));
             } catch (error) {
                 console.error('Error handling request:', error);
                 if (!res.headersSent) res.writeHead(500).end();
@@ -299,7 +296,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32600, /Server already initialized/);
+            expectErrorResponse(errorData, -32_600, /Server already initialized/);
         });
 
         it('should reject batch initialize request', async () => {
@@ -320,7 +317,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32600, /Only one initialization request is allowed/);
+            expectErrorResponse(errorData, -32_600, /Only one initialization request is allowed/);
         });
 
         it('should handle post requests via sse response correctly', async () => {
@@ -338,7 +335,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
                 result: expect.objectContaining({
@@ -376,7 +373,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
                 result: {
@@ -436,7 +433,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
 
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
@@ -469,7 +466,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = (await response.json()) as JSONRPCErrorResponse;
-            expectErrorResponse(errorData, -32000, /Bad Request/);
+            expectErrorResponse(errorData, -32_000, /Bad Request/);
             expect(errorData.id).toBeNull();
         });
 
@@ -482,7 +479,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(404);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32001, /Session not found/);
+            expectErrorResponse(errorData, -32_001, /Session not found/);
         });
 
         it('should establish standalone SSE stream and receive server-initiated messages', async () => {
@@ -519,7 +516,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
                 method: 'notifications/message',
@@ -587,7 +584,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             // Should be rejected
             expect(secondStream.status).toBe(409); // Conflict
             const errorData = await secondStream.json();
-            expectErrorResponse(errorData, -32000, /Only one SSE stream is allowed per session/);
+            expectErrorResponse(errorData, -32_000, /Only one SSE stream is allowed per session/);
         });
 
         it('should reject GET requests without Accept: text/event-stream header', async () => {
@@ -605,7 +602,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(406);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32000, /Client must accept text\/event-stream/);
+            expectErrorResponse(errorData, -32_000, /Client must accept text\/event-stream/);
         });
 
         it('should reject POST requests without proper Accept header', async () => {
@@ -624,7 +621,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(406);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32000, /Client must accept both application\/json and text\/event-stream/);
+            expectErrorResponse(errorData, -32_000, /Client must accept both application\/json and text\/event-stream/);
         });
 
         it('should reject unsupported Content-Type', async () => {
@@ -643,7 +640,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(415);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32000, /Content-Type must be application\/json/);
+            expectErrorResponse(errorData, -32_000, /Content-Type must be application\/json/);
         });
 
         it('should handle JSON-RPC batch notification messages with 202 response', async () => {
@@ -701,7 +698,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32700, /Parse error/);
+            expectErrorResponse(errorData, -32_700, /Parse error/);
         });
 
         it('should include error data in parse error response for unexpected errors', async () => {
@@ -721,7 +718,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = (await response.json()) as JSONRPCErrorResponse;
-            expectErrorResponse(errorData, -32700, /Parse error/);
+            expectErrorResponse(errorData, -32_700, /Parse error/);
             // The error message should contain details about what went wrong
             expect(errorData.error.message).toContain('Invalid JSON');
         });
@@ -759,7 +756,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32000, /Server not initialized/);
+            expectErrorResponse(errorData, -32_000, /Server not initialized/);
 
             // Cleanup
             await stopTestServer({ server: uninitializedServer, transport: uninitializedTransport });
@@ -878,7 +875,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(404);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32001, /Session not found/);
+            expectErrorResponse(errorData, -32_001, /Session not found/);
         });
 
         describe('protocol version header validation', () => {
@@ -926,7 +923,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Bad Request: Unsupported protocol version: .+ \(supported versions: .+\)/);
+                expectErrorResponse(errorData, -32_000, /Bad Request: Unsupported protocol version: .+ \(supported versions: .+\)/);
             });
 
             it('should accept when protocol version differs from negotiated version', async () => {
@@ -963,7 +960,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Bad Request: Unsupported protocol version/);
+                expectErrorResponse(errorData, -32_000, /Bad Request: Unsupported protocol version/);
             });
 
             it('should reject unsupported protocol version on DELETE requests', async () => {
@@ -980,7 +977,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Bad Request: Unsupported protocol version/);
+                expectErrorResponse(errorData, -32_000, /Bad Request: Unsupported protocol version/);
             });
         });
     });
@@ -1032,7 +1029,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
                 result: {
@@ -1068,7 +1065,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const dataLine = eventLines.find(line => line.startsWith('data:'));
             expect(dataLine).toBeDefined();
 
-            const eventData = JSON.parse(dataLine!.substring(5));
+            const eventData = JSON.parse(dataLine!.slice(5));
             expect(eventData).toMatchObject({
                 jsonrpc: '2.0',
                 result: {
@@ -1183,11 +1180,11 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
             const result = await createTestServer({
                 customRequestHandler: async (req, res) => {
                     try {
-                        if (parsedBody !== null) {
+                        if (parsedBody === null) {
+                            await transport.handleRequest(req, res);
+                        } else {
                             await transport.handleRequest(req, res, parsedBody);
                             parsedBody = null; // Reset after use
-                        } else {
-                            await transport.handleRequest(req, res);
                         }
                     } catch (error) {
                         console.error('Error handling request:', error);
@@ -2334,7 +2331,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             // Verify we received the notification that was sent while disconnected
             expect(allText).toContain('Missed while disconnected');
-        }, 15000);
+        }, 15_000);
     });
 
     // Test onsessionclosed callback
@@ -2508,8 +2505,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
                     initializationOrder.push('async-start');
                     // Simulate async operation
                     await new Promise(resolve => setTimeout(resolve, 10));
-                    initializationOrder.push('async-end');
-                    initializationOrder.push(sessionId);
+                    initializationOrder.push('async-end', sessionId);
                 }
             });
 
@@ -2563,8 +2559,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
                     closureOrder.push('async-close-start');
                     // Simulate async operation
                     await new Promise(resolve => setTimeout(resolve, 10));
-                    closureOrder.push('async-close-end');
-                    closureOrder.push(sessionId);
+                    closureOrder.push('async-close-end', sessionId);
                 }
             });
 
diff --git a/packages/server/test/server/streamableHttp.test.ts b/packages/server/test/server/streamableHttp.test.ts
index be53a37f..bf264ced 100644
--- a/packages/server/test/server/streamableHttp.test.ts
+++ b/packages/server/test/server/streamableHttp.test.ts
@@ -105,7 +105,7 @@ function parseSSEData(text: string): unknown {
     if (!dataLine) {
         throw new Error('No data line found in SSE event');
     }
-    return JSON.parse(dataLine.substring(5).trim());
+    return JSON.parse(dataLine.slice(5).trim());
 }
 
 function expectErrorResponse(data: unknown, expectedCode: number, expectedMessagePattern: RegExp): void {
@@ -183,7 +183,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32600, /Server already initialized/);
+                expectErrorResponse(errorData, -32_600, /Server already initialized/);
             });
 
             it('should reject batch initialize request', async () => {
@@ -205,7 +205,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32600, /Only one initialization request is allowed/);
+                expectErrorResponse(errorData, -32_600, /Only one initialization request is allowed/);
             });
         });
 
@@ -278,7 +278,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = (await response.json()) as JSONRPCErrorResponse;
-                expectErrorResponse(errorData, -32000, /Bad Request/);
+                expectErrorResponse(errorData, -32_000, /Bad Request/);
                 expect(errorData.id).toBeNull();
             });
 
@@ -290,7 +290,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(404);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32001, /Session not found/);
+                expectErrorResponse(errorData, -32_001, /Session not found/);
             });
 
             it('should reject request with wrong Accept header', async () => {
@@ -299,7 +299,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(406);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Not Acceptable/);
+                expectErrorResponse(errorData, -32_000, /Not Acceptable/);
             });
 
             it('should reject request with wrong Content-Type header', async () => {
@@ -315,7 +315,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(415);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Unsupported Media Type/);
+                expectErrorResponse(errorData, -32_000, /Unsupported Media Type/);
             });
 
             it('should reject invalid JSON', async () => {
@@ -331,7 +331,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(400);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32700, /Parse error.*Invalid JSON/);
+                expectErrorResponse(errorData, -32_700, /Parse error.*Invalid JSON/);
             });
 
             it('should accept notifications without session and return 202', async () => {
@@ -369,7 +369,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response.status).toBe(406);
                 const errorData = await response.json();
-                expectErrorResponse(errorData, -32000, /Not Acceptable/);
+                expectErrorResponse(errorData, -32_000, /Not Acceptable/);
             });
 
             it('should reject second standalone SSE stream', async () => {
@@ -386,7 +386,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                 expect(response2.status).toBe(409);
                 const errorData = await response2.json();
-                expectErrorResponse(errorData, -32000, /Conflict/);
+                expectErrorResponse(errorData, -32_000, /Conflict/);
             });
         });
 
@@ -628,7 +628,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
                     // Replay events after lastEventId for the same stream
                     const streamId = lastEvent.streamId;
-                    const entries = Array.from(storedEvents.entries());
+                    const entries = [...storedEvents.entries()];
                     let foundLast = false;
 
                     for (const [eventId, event] of entries) {
@@ -739,7 +739,7 @@ describe.each(zodTestMatrix)('$zodVersionLabel', (entry: ZodMatrixEntry) => {
 
             expect(response.status).toBe(400);
             const errorData = await response.json();
-            expectErrorResponse(errorData, -32000, /Unsupported protocol version/);
+            expectErrorResponse(errorData, -32_000, /Unsupported protocol version/);
         });
     });
 
diff --git a/typedoc.config.mjs b/typedoc.config.mjs
index 41a9a0a4..2b4bacf8 100644
--- a/typedoc.config.mjs
+++ b/typedoc.config.mjs
@@ -1,30 +1,33 @@
-import { OptionDefaults } from "typedoc";
-import { findWorkspacePackages } from "@pnpm/workspace.find-packages";
-import { readWorkspaceManifest } from "@pnpm/workspace.read-manifest";
+import { OptionDefaults } from 'typedoc';
+import { findWorkspacePackages } from '@pnpm/workspace.find-packages';
+import { readWorkspaceManifest } from '@pnpm/workspace.read-manifest';
 
 // Read workspace manifest and find all public packages
 const workspaceManifest = await readWorkspaceManifest(process.cwd());
 const packages = await findWorkspacePackages(process.cwd(), {
-    patterns: workspaceManifest?.packages,
+    patterns: workspaceManifest?.packages
 });
 const publicPackages = packages.filter(p => p.manifest.private !== true);
 const entryPoints = publicPackages.map(p => p.rootDir);
 
-console.log('Typedoc selected public packages:', publicPackages.map(p => p.manifest.name));
+console.log(
+    'Typedoc selected public packages:',
+    publicPackages.map(p => p.manifest.name)
+);
 
 export default {
-    name: "MCP TypeScript SDK",
-    entryPointStrategy: "packages",
+    name: 'MCP TypeScript SDK',
+    entryPointStrategy: 'packages',
     entryPoints,
     packageOptions: {
-        blockTags: [...OptionDefaults.blockTags, "@format"]
+        blockTags: [...OptionDefaults.blockTags, '@format']
     },
-    projectDocuments: ["docs/documents.md"],
+    projectDocuments: ['docs/documents.md'],
     navigation: {
         compactFolders: true,
-        includeFolders: false,
+        includeFolders: false
     },
     headings: {
-        readme: false,
-    },
+        readme: false
+    }
 };