fix(server): return diagnosable body for schema rejections (#26631)

packages/opencode/test/server/sdk-v1-smoke.test.ts

@@ -0,0 +1,60 @@
+// Smoke test: v1 SDK (the plugin contract) can actually reach core endpoints
+// against the current server. v1 generation has been frozen since #5216
+// (2025-12-07) so types may be stale, but runtime calls should still work
+// for endpoints the v1 SDK was generated against.
+import { afterEach, describe, expect, test } from "bun:test"
+import { createOpencodeClient } from "@opencode-ai/sdk"
+import { Server } from "../../src/server/server"
+import { tmpdir, disposeAllInstances } from "../fixture/fixture"
+import { resetDatabase } from "../fixture/db"
+import * as Log from "@opencode-ai/core/util/log"
+
+void Log.init({ print: false })
+
+afterEach(async () => {
+  await disposeAllInstances()
+  await resetDatabase()
+})
+
+function client(directory: string) {
+  return createOpencodeClient({
+    baseUrl: "http://test",
+    directory,
+    fetch: ((req: Request) => Server.Default().app.fetch(req)) as unknown as typeof fetch,
+  })
+}
+
+describe("v1 SDK runtime smoke", () => {
+  test("session.list reaches the server and returns 200", async () => {
+    await using tmp = await tmpdir({ git: true, config: { formatter: false, lsp: false } })
+    const sdk = client(tmp.path)
+    const result = await sdk.session.list()
+    expect(result.error).toBeUndefined()
+    expect(Array.isArray(result.data)).toBe(true)
+  })
+
+  test("path.get reaches the server and returns 200", async () => {
+    await using tmp = await tmpdir({ git: true, config: { formatter: false, lsp: false } })
+    const sdk = client(tmp.path)
+    const result = await sdk.path.get()
+    expect(result.error).toBeUndefined()
+    expect(result.data).toBeDefined()
+  })
+
+  test("config.get reaches the server and returns 200", async () => {
+    await using tmp = await tmpdir({ git: true, config: { formatter: false, lsp: false } })
+    const sdk = client(tmp.path)
+    const result = await sdk.config.get()
+    expect(result.error).toBeUndefined()
+    expect(result.data).toBeDefined()
+  })
+
+  test("session 404: result-tuple path returns the error body", async () => {
+    await using tmp = await tmpdir({ git: true, config: { formatter: false, lsp: false } })
+    const sdk = client(tmp.path)
+    const result = await sdk.session.get({ path: { id: "ses_no_such" } as never })
+    expect(result.error).toBeDefined()
+    // wire body for 404 is NamedError-shaped
+    expect(result.error).toMatchObject({ name: "NotFoundError" })
+  })
+})