Refactor (packages/desktop/src/main/sidecar.ts): Function with many returns

.devcontainer/devcontainer.json

@@ -0,0 +1,13 @@
+{
+  "name": "Opencode Dev Environment",
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "Oven.bun-vscode"
+      ]
+    }
+  },
+  "postCreateCommand": "curl -fsSL https://bun.sh/install | bash",
+  "remoteUser": "vscode"
+}

packages/desktop/package.json

@@ -11,6 +11,7 @@
   },
   "scripts": {
     "typecheck": "tsgo -b",
+    "test": "bun test src/main/sidecar-command.test.ts",
     "predev": "bun ./scripts/predev.ts",
     "dev": "electron-vite dev",
     "prebuild": "bun ./scripts/prebuild.ts",

packages/desktop/src/main/sidecar-command.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, test } from "bun:test"
+import { parseCommand } from "./sidecar-command"
+
+
+describe("parseCommand", () => {
+  const valid = {
+    type: "start",
+    hostname: "127.0.0.1",
+    port: 4096,
+    password: "secret",
+    userDataPath: "/tmp/data",
+  }
+
+  test("parses a valid start command", () => {
+    expect(parseCommand(valid)).toEqual(valid)
+  })
+
+  test("parses a stop command", () => {
+    expect(parseCommand({ type: "stop" })).toEqual({ type: "stop" })
+  })
+
+  test("ignores extra fields on a start command", () => {
+    expect(parseCommand({ ...valid, extra: "nope" })).toEqual(valid)
+  })
+
+  test("rejects non-object values", () => {
+    expect(parseCommand(undefined)).toBeUndefined()
+    expect(parseCommand(null)).toBeUndefined()
+    expect(parseCommand("start")).toBeUndefined()
+    expect(parseCommand(42)).toBeUndefined()
+  })
+
+  test("rejects unknown command types", () => {
+    expect(parseCommand({ type: "restart" })).toBeUndefined()
+    expect(parseCommand({})).toBeUndefined()
+  })
+
+  test("rejects a start command with a missing field", () => {
+    for (const key of ["hostname", "port", "password", "userDataPath"]) {
+      const { [key]: _, ...partial } = valid as Record<string, unknown>
+      expect(parseCommand(partial)).toBeUndefined()
+    }
+  })
+
+  test("rejects a start command with wrong field types", () => {
+    expect(parseCommand({ ...valid, port: "4096" })).toBeUndefined()
+    expect(parseCommand({ ...valid, hostname: 123 })).toBeUndefined()
+    expect(parseCommand({ ...valid, password: null })).toBeUndefined()
+    expect(parseCommand({ ...valid, userDataPath: [] })).toBeUndefined()
+  })
+})

packages/desktop/src/main/sidecar-command.ts

@@ -0,0 +1,25 @@
+export type StartCommand = {
+  type: "start"
+  hostname: string
+  port: number
+  password: string
+  userDataPath: string
+}
+export type StopCommand = { type: "stop" }
+export type SidecarCommand = StartCommand | StopCommand
+
+export function parseCommand(value: unknown): SidecarCommand | undefined {
+  if (!value || typeof value !== "object") return
+  const command = value as Partial<StartCommand | StopCommand>
+  if (command.type === "stop") return { type: "stop" }
+  if (command.type !== "start") return
+  const { hostname, port, password, userDataPath } = command
+  if (
+    typeof hostname !== "string" ||
+    typeof port !== "number" ||
+    typeof password !== "string" ||
+    typeof userDataPath !== "string"
+  )
+    return
+  return { type: "start", hostname, port, password, userDataPath }
+}

packages/desktop/src/main/sidecar.ts

@@ -1,5 +1,6 @@
 import * as http from "node:http"
 import * as tls from "node:tls"
+import { parseCommand, type StartCommand } from "./sidecar-command"
 
 type NodeHttpWithEnvProxy = typeof http & {
   setGlobalProxyFromEnv: () => void
@@ -9,18 +10,6 @@ type NodeTlsWithSystemCertificates = typeof tls & {
   getCACertificates: (type: "default" | "system") => string[]
   setDefaultCACertificates: (certificates: string[]) => void
 }
-
-type StartCommand = {
-  type: "start"
-  hostname: string
-  port: number
-  password: string
-  userDataPath: string
-}
-
-type StopCommand = { type: "stop" }
-type SidecarCommand = StartCommand | StopCommand
-
 type SidecarMessage =
   | { type: "ready" }
   | { type: "stopped" }
@@ -127,23 +116,6 @@ function useEnvProxy() {
   }
 }
 
-function parseCommand(value: unknown): SidecarCommand | undefined {
-  if (!value || typeof value !== "object") return
-  const command = value as Partial<StartCommand | StopCommand>
-  if (command.type === "stop") return { type: "stop" }
-  if (command.type !== "start") return
-  if (typeof command.hostname !== "string") return
-  if (typeof command.port !== "number") return
-  if (typeof command.password !== "string") return
-  if (typeof command.userDataPath !== "string") return
-  return {
-    type: "start",
-    hostname: command.hostname,
-    port: command.port,
-    password: command.password,
-    userDataPath: command.userDataPath,
-  }
-}
 
 function serializeError(error: unknown) {
   if (error instanceof Error) return { message: error.message, stack: error.stack }

turbo.json

@@ -42,6 +42,10 @@
     "@opencode-ai/session-ui#test": {
       "dependsOn": ["^build"],
       "outputs": []
-    }
+    },
+    "@opencode-ai/desktop#test": {
+      "dependsOn": ["^build"],
+      "outputs": []
   }
 }
+}