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

packages/opencode/test/server/httpapi-schema-error-body.test.ts

@@ -0,0 +1,162 @@
+import { afterEach, describe, expect } from "bun:test"
+import { Effect } from "effect"
+import { eq } from "drizzle-orm"
+import * as Database from "@/storage/db"
+import { ModelID, ProviderID } from "../../src/provider/schema"
+import { WithInstance } from "../../src/project/with-instance"
+import { Server } from "../../src/server/server"
+import { Session } from "@/session/session"
+import { SessionPaths } from "../../src/server/routes/instance/httpapi/groups/session"
+import { SyncPaths } from "../../src/server/routes/instance/httpapi/groups/sync"
+import { MessageID, PartID } from "../../src/session/schema"
+import { PartTable } from "@/session/session.sql"
+import { resetDatabase } from "../fixture/db"
+import { disposeAllInstances, tmpdir } from "../fixture/fixture"
+import { it } from "../lib/effect"
+
+afterEach(async () => {
+  await disposeAllInstances()
+  await resetDatabase()
+})
+
+const withTmp = <A, E, R>(
+  options: Parameters<typeof tmpdir>[0],
+  fn: (tmp: Awaited<ReturnType<typeof tmpdir>>) => Effect.Effect<A, E, R>,
+) =>
+  Effect.acquireRelease(
+    Effect.promise(() => tmpdir(options)),
+    (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+  ).pipe(Effect.flatMap(fn))
+
+async function seedCorruptStepFinishPart(directory: string) {
+  return WithInstance.provide({
+    directory,
+    fn: () =>
+      Effect.runPromise(
+        Effect.gen(function* () {
+          const session = yield* Session.Service
+          const info = yield* session.create({})
+          const message = yield* session.updateMessage({
+            id: MessageID.ascending(),
+            role: "user",
+            sessionID: info.id,
+            agent: "build",
+            model: { providerID: ProviderID.make("test"), modelID: ModelID.make("test") },
+            time: { created: Date.now() },
+          })
+          const partID = PartID.ascending()
+          yield* session.updatePart({
+            id: partID,
+            sessionID: info.id,
+            messageID: message.id,
+            type: "step-finish",
+            reason: "stop",
+            cost: 0,
+            tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
+          })
+          // Schema.Finite still rejects NaN at encode — exact mirror of the
+          // corrupt row that broke the user's session in the OMO/Windows bug.
+          Database.use((db) =>
+            db
+              .update(PartTable)
+              .set({
+                data: {
+                  type: "step-finish",
+                  reason: "stop",
+                  cost: 0,
+                  tokens: { input: 0, output: NaN, reasoning: 0, cache: { read: 0, write: 0 } },
+                } as never, // drizzle's .set() can't narrow the discriminated union
+              })
+              .where(eq(PartTable.id, partID))
+              .run(),
+          )
+          return info.id
+        }).pipe(Effect.provide(Session.defaultLayer)),
+      ),
+  })
+}
+
+describe("schema-rejection wire shape", () => {
+  it.live(
+    "Payload schema rejection returns NamedError-shaped JSON, not empty",
+    withTmp({ git: true, config: { formatter: false, lsp: false } }, (tmp) =>
+      Effect.gen(function* () {
+        const res = yield* Effect.promise(async () =>
+          Server.Default().app.request(SyncPaths.history, {
+            method: "POST",
+            headers: { "x-opencode-directory": tmp.path, "content-type": "application/json" },
+            body: JSON.stringify({ aggregate: -1 }),
+          }),
+        )
+        const body = yield* Effect.promise(async () => res.text())
+        expect(res.status).toBe(400)
+        expect(res.headers.get("content-type") ?? "").toContain("application/json")
+        const parsed = JSON.parse(body)
+        expect(parsed).toMatchObject({
+          name: "BadRequest",
+          data: { kind: expect.stringMatching(/^(Body|Payload)$/) },
+        })
+        expect(parsed.data.message).toEqual(expect.any(String))
+        expect(parsed.data.message.length).toBeGreaterThan(0)
+      }),
+    ),
+  )
+
+  it.live(
+    "Query schema rejection returns NamedError-shaped JSON",
+    withTmp({ git: true, config: { formatter: false, lsp: false } }, (tmp) =>
+      Effect.gen(function* () {
+        // /find/file?limit=999999 violates the limit constraint check.
+        const url = `/find/file?query=foo&limit=999999&directory=${encodeURIComponent(tmp.path)}`
+        const res = yield* Effect.promise(async () => Server.Default().app.request(url))
+        const body = yield* Effect.promise(async () => res.text())
+        expect(res.status).toBe(400)
+        const parsed = JSON.parse(body)
+        expect(parsed).toMatchObject({ name: "BadRequest", data: { kind: "Query" } })
+      }),
+    ),
+  )
+
+  it.live(
+    "rejected request body never echoes back unbounded — message is capped",
+    // Defense against DoS-amplification + secret-echo: Effect's Issue formatter
+    // dumps the rejected `actual` verbatim. A multi-MB invalid array would
+    // become a multi-MB 400 response and log line. Cap kicks in around 1KB.
+    withTmp({ git: true, config: { formatter: false, lsp: false } }, (tmp) =>
+      Effect.gen(function* () {
+        const huge = "X".repeat(50_000)
+        const res = yield* Effect.promise(async () =>
+          Server.Default().app.request(SyncPaths.history, {
+            method: "POST",
+            headers: { "x-opencode-directory": tmp.path, "content-type": "application/json" },
+            body: JSON.stringify({ aggregate: huge }),
+          }),
+        )
+        const body = yield* Effect.promise(async () => res.text())
+        expect(res.status).toBe(400)
+        // 1 KB cap + small JSON envelope ≈ <2 KB — never tens of KB.
+        expect(body.length).toBeLessThan(2 * 1024)
+        const parsed = JSON.parse(body)
+        expect(parsed.data.message).not.toContain(huge)
+      }),
+    ),
+  )
+
+  it.live(
+    "response-encode failure: corrupted stored row returns NamedError-shaped JSON with field path",
+    withTmp({ config: { formatter: false, lsp: false } }, (tmp) =>
+      Effect.gen(function* () {
+        const sessionID = yield* Effect.promise(() => seedCorruptStepFinishPart(tmp.path))
+        const url = `${SessionPaths.messages.replace(":sessionID", sessionID)}?limit=80&directory=${encodeURIComponent(tmp.path)}`
+        const res = yield* Effect.promise(async () => Server.Default().app.request(url))
+        const body = yield* Effect.promise(async () => res.text())
+        expect(res.status).toBe(400)
+        expect(res.headers.get("content-type") ?? "").toContain("application/json")
+        const parsed = JSON.parse(body)
+        expect(parsed).toMatchObject({ name: "BadRequest", data: { kind: "Body" } })
+        // Field path in data.message — what made this PR worth shipping.
+        expect(parsed.data.message).toMatch(/output/)
+      }),
+    ),
+  )
+})

packages/opencode/test/server/sdk-error-shape.test.ts

@@ -52,23 +52,33 @@ describe("v2 SDK error shape", () => {
     })
   })
 
-  test("400 with empty body throws a real Error naming the status", async () => {
+  test("400 schema rejection: SDK extracts the field-level reason from the NamedError body", async () => {
+    // Canary for the #26631 wire shape. Asserts the contract end-to-end:
+    // server emits {name:"BadRequest", data:{message, kind}}, SDK's
+    // wrapClientError extracts .data.message into Error.message. If either
+    // side regresses (#26457 reverted because both layers were missing),
+    // this test fails before users see (empty response body).
     await using tmp = await tmpdir({ config: { formatter: false, lsp: false } })
     const sdk = client(tmp.path)
 
     let caught: unknown
     try {
-      // POST /sync/history with `aggregate: -1` triggers schema validation
-      // that returns an empty 400 body (verified via plan-mode probe).
-      await sdk.sync.history.list({ aggregate: -1 } as any, { throwOnError: true })
+      await sdk.sync.history.list({ body: { aggregate: -1 } as any }, { throwOnError: true })
     } catch (e) {
       caught = e
     }
 
     expect(caught).toBeInstanceOf(Error)
     const err = caught as Error
-    const cause = err.cause as { status?: number }
-    expect(err.message.length).toBeGreaterThan(0)
+    const cause = err.cause as { body?: any; status?: number }
     expect(cause.status).toBe(400)
+    expect(cause.body).toMatchObject({
+      name: "BadRequest",
+      data: { kind: expect.stringMatching(/^(Body|Payload)$/) },
+    })
+    expect(typeof cause.body.data.message).toBe("string")
+    expect(cause.body.data.message.length).toBeGreaterThan(0)
+    // Whatever the server put in data.message must be what the user sees.
+    expect(err.message).toBe(cause.body.data.message)
   })
 })

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" })
+  })
+})