fix: Catch local API server various errors (#6548)

* fix: Catch local API server various errors

* chore: Add tests to cover error catches

src-tauri/src/core/server/proxy.rs

@@ -749,7 +749,13 @@ pub async fn start_server(
         }
     });
 
-    let server = Server::bind(&addr).serve(make_svc);
+    let server = match Server::try_bind(&addr) {
+        Ok(builder) => builder.serve(make_svc),
+        Err(e) => {
+            log::error!("Failed to bind to {}: {}", addr, e);
+            return Err(Box::new(e));
+        }
+    };
     log::info!("Jan API server started on http://{}", addr);
 
     let server_task = tokio::spawn(async move {

web-app/src/hooks/__tests__/useLocalApiServer.test.ts

@@ -419,7 +419,6 @@ describe('useLocalApiServer', () => {
       expect(result.current.serverHost).toBe('127.0.0.1') // Should remain default
       expect(result.current.apiPrefix).toBe('/v1') // Should remain default
 
-
       act(() => {
         result.current.addTrustedHost('example.com')
       })
@@ -428,4 +427,240 @@ describe('useLocalApiServer', () => {
       expect(result.current.serverPort).toBe(9000) // Should remain changed
     })
   })
+
+  describe('error handling scenarios', () => {
+    it('should provide correct configuration for port conflict error messages', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test common conflicting ports and verify they're stored correctly
+      // These values will be used in error messages when port conflicts occur
+      const conflictPorts = [
+        { port: 80, expectedMessage: 'Port 80 is already in use' },
+        { port: 443, expectedMessage: 'Port 443 is already in use' },
+        { port: 3000, expectedMessage: 'Port 3000 is already in use' },
+        { port: 8080, expectedMessage: 'Port 8080 is already in use' },
+        { port: 11434, expectedMessage: 'Port 11434 is already in use' }
+      ]
+
+      conflictPorts.forEach(({ port, expectedMessage }) => {
+        act(() => {
+          result.current.setServerPort(port)
+        })
+
+        expect(result.current.serverPort).toBe(port)
+        // Verify the port value that would be used in error message construction
+        expect(`Port ${result.current.serverPort} is already in use`).toBe(expectedMessage)
+      })
+    })
+
+    it('should validate API key requirements for error prevention', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test empty API key - should trigger validation error
+      act(() => {
+        result.current.setApiKey('')
+      })
+      expect(result.current.apiKey).toBe('')
+      expect(result.current.apiKey.trim().length === 0).toBe(true) // Would fail validation
+
+      // Test whitespace only API key - should trigger validation error
+      act(() => {
+        result.current.setApiKey('   ')
+      })
+      expect(result.current.apiKey).toBe('   ')
+      expect(result.current.apiKey.toString().trim().length === 0).toBe(true) // Would fail validation
+
+      // Test valid API key - should pass validation
+      act(() => {
+        result.current.setApiKey('sk-valid-api-key-123')
+      })
+      expect(result.current.apiKey).toBe('sk-valid-api-key-123')
+      expect(result.current.apiKey.toString().trim().length > 0).toBe(true) // Would pass validation
+    })
+
+    it('should configure trusted hosts for CORS error handling', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Add hosts that are commonly involved in CORS errors
+      const corsRelatedHosts = ['localhost', '127.0.0.1', '0.0.0.0', 'example.com']
+
+      corsRelatedHosts.forEach((host) => {
+        act(() => {
+          result.current.addTrustedHost(host)
+        })
+      })
+
+      expect(result.current.trustedHosts).toEqual(corsRelatedHosts)
+      expect(result.current.trustedHosts.length).toBe(4) // Verify count for error context
+
+      // Test removing a critical host that might cause access errors
+      act(() => {
+        result.current.removeTrustedHost('127.0.0.1')
+      })
+
+      expect(result.current.trustedHosts).toEqual(['localhost', '0.0.0.0', 'example.com'])
+      expect(result.current.trustedHosts.includes('127.0.0.1')).toBe(false) // Might cause localhost access errors
+    })
+
+    it('should configure timeout values that prevent timeout errors', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test very short timeout - likely to cause timeout errors
+      act(() => {
+        result.current.setProxyTimeout(1)
+      })
+      expect(result.current.proxyTimeout).toBe(1)
+      expect(result.current.proxyTimeout < 60).toBe(true) // Likely to timeout
+
+      // Test reasonable timeout - should prevent timeout errors
+      act(() => {
+        result.current.setProxyTimeout(600)
+      })
+      expect(result.current.proxyTimeout).toBe(600)
+      expect(result.current.proxyTimeout >= 600).toBe(true) // Should be sufficient
+
+      // Test very long timeout - prevents timeout but might cause UX issues
+      act(() => {
+        result.current.setProxyTimeout(3600)
+      })
+      expect(result.current.proxyTimeout).toBe(3600)
+      expect(result.current.proxyTimeout > 1800).toBe(true) // Very long timeout
+    })
+
+    it('should configure server host to prevent binding errors', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test localhost binding - generally safe
+      act(() => {
+        result.current.setServerHost('127.0.0.1')
+      })
+      expect(result.current.serverHost).toBe('127.0.0.1')
+      expect(result.current.serverHost === '127.0.0.1').toBe(true) // Localhost binding
+
+      // Test all interfaces binding - might cause permission errors on some systems
+      act(() => {
+        result.current.setServerHost('0.0.0.0')
+      })
+      expect(result.current.serverHost).toBe('0.0.0.0')
+      expect(result.current.serverHost === '0.0.0.0').toBe(true) // All interfaces binding (potential permission issues)
+
+      // Verify host format for error message construction
+      expect(result.current.serverHost.includes('.')).toBe(true) // Valid IP format
+    })
+  })
+
+  describe('integration error scenarios', () => {
+    it('should provide configuration data that matches error message patterns', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Set up configuration that would be used in actual error messages
+      act(() => {
+        result.current.setServerHost('127.0.0.1')
+        result.current.setServerPort(8080)
+        result.current.setApiKey('test-key')
+      })
+
+      // Verify values match what error handling expects
+      const config = {
+        host: result.current.serverHost,
+        port: result.current.serverPort,
+        apiKey: result.current.apiKey
+      }
+
+      expect(config.host).toBe('127.0.0.1')
+      expect(config.port).toBe(8080)
+      expect(config.apiKey).toBe('test-key')
+
+      // These values would be used in error messages like:
+      // "Failed to bind to 127.0.0.1:8080: Address already in use"
+      // "Port 8080 is already in use. Please try a different port."
+      const expectedErrorContext = `${config.host}:${config.port}`
+      expect(expectedErrorContext).toBe('127.0.0.1:8080')
+    })
+
+    it('should detect invalid configurations that would cause startup errors', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test configuration that would prevent server startup
+      act(() => {
+        result.current.setApiKey('') // Invalid - empty API key
+        result.current.setServerPort(0) // Invalid - port 0
+      })
+
+      // Verify conditions that would trigger validation errors
+      const hasValidApiKey = !!(result.current.apiKey && result.current.apiKey.toString().trim().length > 0)
+      const hasValidPort = result.current.serverPort > 0 && result.current.serverPort <= 65535
+
+      expect(hasValidApiKey).toBe(false) // Would trigger "Missing API key" error
+      expect(hasValidPort).toBe(false) // Would trigger "Invalid port" error
+
+      // Fix configuration
+      act(() => {
+        result.current.setApiKey('valid-key')
+        result.current.setServerPort(3000)
+      })
+
+      const hasValidApiKeyFixed = !!(result.current.apiKey && result.current.apiKey.toString().trim().length > 0)
+      const hasValidPortFixed = result.current.serverPort > 0 && result.current.serverPort <= 65535
+
+      expect(hasValidApiKeyFixed).toBe(true) // Should pass validation
+      expect(hasValidPortFixed).toBe(true) // Should pass validation
+    })
+  })
+
+  describe('configuration validation', () => {
+    it('should maintain consistent state for server configuration', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Set up a complete server configuration
+      act(() => {
+        result.current.setServerHost('127.0.0.1')
+        result.current.setServerPort(8080)
+        result.current.setApiPrefix('/api/v1')
+        result.current.setApiKey('test-key-123')
+        result.current.setTrustedHosts(['localhost', '127.0.0.1'])
+        result.current.setProxyTimeout(300)
+        result.current.setCorsEnabled(true)
+        result.current.setVerboseLogs(false)
+      })
+
+      // Verify all settings are consistent
+      expect(result.current.serverHost).toBe('127.0.0.1')
+      expect(result.current.serverPort).toBe(8080)
+      expect(result.current.apiPrefix).toBe('/api/v1')
+      expect(result.current.apiKey).toBe('test-key-123')
+      expect(result.current.trustedHosts).toEqual(['localhost', '127.0.0.1'])
+      expect(result.current.proxyTimeout).toBe(300)
+      expect(result.current.corsEnabled).toBe(true)
+      expect(result.current.verboseLogs).toBe(false)
+    })
+
+    it('should handle edge cases in configuration values', () => {
+      const { result } = renderHook(() => useLocalApiServer())
+
+      // Test edge case: empty API prefix
+      act(() => {
+        result.current.setApiPrefix('')
+      })
+      expect(result.current.apiPrefix).toBe('')
+
+      // Test edge case: API prefix without leading slash
+      act(() => {
+        result.current.setApiPrefix('v1')
+      })
+      expect(result.current.apiPrefix).toBe('v1')
+
+      // Test edge case: minimum port number
+      act(() => {
+        result.current.setServerPort(1)
+      })
+      expect(result.current.serverPort).toBe(1)
+
+      // Test edge case: maximum valid port number
+      act(() => {
+        result.current.setServerPort(65535)
+      })
+      expect(result.current.serverPort).toBe(65535)
+    })
+  })
 })

web-app/src/routes/settings/local-api-server.tsx

@@ -22,6 +22,7 @@ import { ApiKeyInput } from '@/containers/ApiKeyInput'
 import { useEffect, useState } from 'react'
 import { PlatformGuard } from '@/lib/platform/PlatformGuard'
 import { PlatformFeature } from '@/lib/platform'
+import { toast } from 'sonner'
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export const Route = createFileRoute(route.settings.local_api_server as any)({
@@ -133,6 +134,11 @@ function LocalAPIServerContent() {
   const toggleAPIServer = async () => {
     // Validate API key before starting server
     if (serverStatus === 'stopped') {
+      console.log('Starting server with port:', serverPort)
+      toast.info('Starting server...', {
+        description: `Attempting to start server on port ${serverPort}`
+      })
+
       if (!apiKey || apiKey.toString().trim().length === 0) {
         setShowApiKeyError(true)
         return
@@ -179,9 +185,39 @@ function LocalAPIServerContent() {
           setServerStatus('running')
         })
         .catch((error: unknown) => {
-          console.error('Error starting server:', error)
+          console.error('Error starting server or model:', error)
           setServerStatus('stopped')
           setIsModelLoading(false) // Reset loading state on error
+          toast.dismiss()
+
+          // Extract error message from various error formats
+          const errorMsg = error && typeof error === 'object' && 'message' in error
+            ? String(error.message)
+            : String(error)
+
+          // Port-related errors (highest priority)
+          if (errorMsg.includes('Address already in use')) {
+            toast.error('Port has been occupied', {
+              description: `Port ${serverPort} is already in use. Please try a different port.`
+            })
+          }
+          // Model-related errors
+          else if (errorMsg.includes('Invalid or inaccessible model path')) {
+            toast.error('Invalid or inaccessible model path', {
+              description: errorMsg
+            })
+          }
+          else if (errorMsg.includes('model')) {
+            toast.error('Failed to start model', {
+              description: errorMsg
+            })
+          }
+          // Generic server errors
+          else {
+            toast.error('Failed to start server', {
+              description: errorMsg
+            })
+          }
         })
     } else {
       setServerStatus('pending')