From 4ebc38a8e018eb2238086910600349c7d61a01c8 Mon Sep 17 00:00:00 2001
From: Steve Yegge <stevey@sourcegraph.com>
Date: Mon, 29 Jan 2024 09:35:34 -0800
Subject: [PATCH] Allow agent to be debugged by IntelliJ

If you set some new env vars you can spawn the agent with --inspect,
which allows IntelliJ to connect to it. There is also an option to
have the agent listen on a socket for the client to attach.
---
 .gitignore                    |  1 +
 agent/src/agent.ts            |  2 +-
 agent/src/cli/jsonrpc.ts      | 51 +++++++++++++++++++++++++----------
 vscode/src/chat/protocol.ts   |  2 +-
 vscode/src/jsonrpc/jsonrpc.ts |  2 +-
 5 files changed, 41 insertions(+), 17 deletions(-)

diff --git a/.gitignore b/.gitignore
index 4fa4b43995a..a4bec3de8ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ dist/
 .DS_Store
 .env
 .idea/
+.run/
 playwright/**/*.webm
 **/*.iml
 **/*.vsix
diff --git a/agent/src/agent.ts b/agent/src/agent.ts
index f3dc2f2e0de..d0fda94a5bb 100644
--- a/agent/src/agent.ts
+++ b/agent/src/agent.ts
@@ -142,7 +142,7 @@ export class Agent extends MessageHandler {
     public workspace = new AgentWorkspaceDocuments({
         edit: (uri, callback, options) => {
             if (this.clientInfo?.capabilities?.edit !== 'enabled') {
-                logDebug('CodyAgent', 'client does not support operation: AgenTextDocument.edit()')
+                logDebug('CodyAgent', 'client does not support operation: textDocument/edit')
                 return Promise.resolve(false)
             }
             const edits: TextEdit[] = []
diff --git a/agent/src/cli/jsonrpc.ts b/agent/src/cli/jsonrpc.ts
index 6fa08183c11..551e1ccaf76 100644
--- a/agent/src/cli/jsonrpc.ts
+++ b/agent/src/cli/jsonrpc.ts
@@ -1,6 +1,7 @@
 import type { EXPIRY_STRATEGY, MODE, Polly, Request } from '@pollyjs/core'
 import * as commander from 'commander'
 import { Command, Option } from 'commander'
+import { createServer } from 'net'
 
 import { startPollyRecording } from '../../../vscode/src/testutils/polly'
 import { Agent } from '../agent'
@@ -44,6 +45,11 @@ function expiryStrategyOption(value: string): EXPIRY_STRATEGY {
     }
 }
 
+const isDebugMode = process.env.CODY_AGENT_DEBUG_REMOTE === 'true'
+const debugPort = process.env.CODY_AGENT_DEBUG_PORT
+    ? parseInt(process.env.CODY_AGENT_DEBUG_PORT, 10)
+    : 3113
+
 export const jsonrpcCommand = new Command('jsonrpc')
     .description(
         'Interact with the Agent using JSON-RPC via stdout/stdin. ' +
@@ -132,21 +138,38 @@ export const jsonrpcCommand = new Command('jsonrpc')
             process.exit(1)
         }
 
-        if (process.env.CODY_DEBUG === 'true') {
-            process.stderr.write('Starting Cody Agent...\n')
+        if (isDebugMode) {
+            const server = createServer(socket => {
+                setupAgentCommunication(polly, networkRequests, socket, socket)
+            })
+
+            server.listen(debugPort, () => {
+                console.log(`Agent debug server listening on port ${debugPort}`)
+            })
+        } else {
+            setupAgentCommunication(polly, networkRequests, process.stdin, process.stdout)
         }
+    })
 
-        const agent = new Agent({ polly, networkRequests })
+function setupAgentCommunication(
+    polly: Polly | undefined,
+    networkRequests: Request[],
+    stdin: NodeJS.ReadableStream,
+    stdout: NodeJS.WritableStream
+) {
+    const agent = new Agent({ polly, networkRequests })
 
-        // Force the agent process to exit when stdin/stdout close as an attempt to
-        // prevent zombie agent processes. We experienced this problem when we
-        // forcefully exit the IntelliJ process during local `./gradlew :runIde`
-        // workflows. We manually confirmed that this logic makes the agent exit even
-        // when we forcefully quit IntelliJ
-        // https://github.com/sourcegraph/cody/pull/1439#discussion_r1365610354
-        process.stdout.on('close', () => process.exit(1))
-        process.stdin.on('close', () => process.exit(1))
+    // Force the agent process to exit when stdin/stdout close as an attempt to
+    // prevent zombie agent processes. We experienced this problem when we
+    // forcefully exit the IntelliJ process during local `./gradlew :runIde`
+    // workflows. We manually confirmed that this logic makes the agent exit even
+    // when we forcefully quit IntelliJ
+    // https://github.com/sourcegraph/cody/pull/1439#discussion_r1365610354
+    if (!isDebugMode) {
+        stdout.on('close', () => process.exit(1))
+        stdin.on('close', () => process.exit(1))
+    }
 
-        process.stdin.pipe(agent.messageDecoder)
-        agent.messageEncoder.pipe(process.stdout)
-    })
+    stdin.pipe(agent.messageDecoder)
+    agent.messageEncoder.pipe(stdout)
+}
diff --git a/vscode/src/chat/protocol.ts b/vscode/src/chat/protocol.ts
index c08330d5e82..12fa877f3d0 100644
--- a/vscode/src/chat/protocol.ts
+++ b/vscode/src/chat/protocol.ts
@@ -50,7 +50,7 @@ export type WebviewMessage =
           command: 'openLocalFileWithRange'
           filePath: string
           // Note: we're not using vscode.Range objects or nesting here, as the protocol
-          // tends ot munge the type in a weird way (nested fields become array indices).
+          // tends to munge the type in a weird way (nested fields become array indices).
           range?: {
               startLine: number
               startCharacter: number
diff --git a/vscode/src/jsonrpc/jsonrpc.ts b/vscode/src/jsonrpc/jsonrpc.ts
index bb7a5fbb21d..f516040fd1d 100644
--- a/vscode/src/jsonrpc/jsonrpc.ts
+++ b/vscode/src/jsonrpc/jsonrpc.ts
@@ -105,7 +105,7 @@ type MessageHandlerCallback = (err: Error | null, msg: Message | null) => void
 
 /**
  * Absolute path to a file where the agent can write low-level debugging logs to
- * trace all incoming/outgoin JSON messages.
+ * trace all incoming/outgoing JSON messages.
  */
 const tracePath = process.env.CODY_AGENT_TRACE_PATH ?? ''