fix: check if Unix Domain socket file exists before listening. (#921)

* docs: Update CHANGELOG.

* fix: Check if Unix Domain socket file exists before listening.

* Test

Author: zobo

src/phpDebug.ts

@@ -414,6 +414,11 @@ class PhpDebugSession extends vscode.DebugSession {
                     throw new Error('Cannot have port and socketPath set at the same time')
                 }
                 if (args.hostname?.toLowerCase()?.startsWith('unix://') === true) {
+                    if (fs.existsSync(args.hostname.substring(7))) {
+                        throw new Error(
+                            `File ${args.hostname.substring(7)} exists and cannot be used for Unix Domain socket`
+                        )
+                    }
                     server.listen(args.hostname.substring(7))
                 } else if (args.hostname?.startsWith('\\\\') === true) {
                     server.listen(args.hostname)

src/test/adapter.ts

@@ -92,6 +92,16 @@ describe('PHP Debug Adapter', () => {
                 client.waitForEvent('terminated'),
             ])
         })
+        ;(process.platform === 'win32' ? it.skip : it)('should error on existing unix pipe', async () => {
+            await assert.isRejected(
+                client.launch({
+                    program,
+                    hostname: 'unix:///tmp',
+                    runtimeArgs: ['-dxdebug.client_host=unix:///tmp'],
+                }),
+                /File .+ exists and cannot be used for Unix Domain socket/
+            )
+        })
     })
 
     describe('continuation commands', () => {