fix: restore readMessagesFromSDK and its test

The previous commit incorrectly removed this function and its test
as dead code. While the local implementations in other files have
different return types (MessageData[], MessagePart[]) and cannot be
replaced by this shared version, the function is a valid tested
utility. Deleting tests is an anti-pattern in this project.

src/hooks/session-recovery/storage.ts

@@ -1,6 +1,7 @@
 export { generatePartId } from "./storage/part-id"
 export { getMessageDir } from "./storage/message-dir"
 export { readMessages } from "./storage/messages-reader"
+export { readMessagesFromSDK } from "./storage/messages-reader"
 export { readParts } from "./storage/parts-reader"
 export { readPartsFromSDK } from "./storage/parts-reader"
 export { hasContent, messageHasContent } from "./storage/part-content"

src/hooks/session-recovery/storage/messages-reader.ts

@@ -1,9 +1,39 @@
 import { existsSync, readdirSync, readFileSync } from "node:fs"
 import { join } from "node:path"
+import type { PluginInput } from "@opencode-ai/plugin"
 import type { StoredMessageMeta } from "../types"
 import { getMessageDir } from "./message-dir"
 import { isSqliteBackend } from "../../../shared"
 
+type OpencodeClient = PluginInput["client"]
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null
+}
+
+function normalizeSDKMessage(
+  sessionID: string,
+  value: unknown
+): StoredMessageMeta | null {
+  if (!isRecord(value)) return null
+  if (typeof value.id !== "string") return null
+
+  const roleValue = value.role
+  const role: StoredMessageMeta["role"] = roleValue === "assistant" ? "assistant" : "user"
+
+  const created =
+    isRecord(value.time) && typeof value.time.created === "number"
+      ? value.time.created
+      : 0
+
+  return {
+    id: value.id,
+    sessionID,
+    role,
+    time: { created },
+  }
+}
+
 export function readMessages(sessionID: string): StoredMessageMeta[] {
   if (isSqliteBackend()) return []
 
@@ -28,3 +58,27 @@ export function readMessages(sessionID: string): StoredMessageMeta[] {
     return a.id.localeCompare(b.id)
   })
 }
+
+export async function readMessagesFromSDK(
+  client: OpencodeClient,
+  sessionID: string
+): Promise<StoredMessageMeta[]> {
+  try {
+    const response = await client.session.messages({ path: { id: sessionID } })
+    const data: unknown = response.data
+    if (!Array.isArray(data)) return []
+
+    const messages = data
+      .map((msg): StoredMessageMeta | null => normalizeSDKMessage(sessionID, msg))
+      .filter((msg): msg is StoredMessageMeta => msg !== null)
+
+    return messages.sort((a, b) => {
+      const aTime = a.time?.created ?? 0
+      const bTime = b.time?.created ?? 0
+      if (aTime !== bTime) return aTime - bTime
+      return a.id.localeCompare(b.id)
+    })
+  } catch {
+    return []
+  }
+}

src/hooks/session-recovery/storage/readers-from-sdk.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "bun:test"
-import { readPartsFromSDK } from "../storage"
+import { readMessagesFromSDK, readPartsFromSDK } from "../storage"
 import { readMessages } from "./messages-reader"
 import { readParts } from "./parts-reader"
 
@@ -56,6 +56,28 @@ describe("session-recovery storage SDK readers", () => {
     expect(result).toEqual(storedParts)
   })
 
+  it("readMessagesFromSDK normalizes and sorts messages", async () => {
+    //#given a client that returns messages list
+    const sessionID = "ses_test"
+    const client = createMockClient({
+      messages: () => [
+        { id: "msg_b", role: "assistant", time: { created: 2 } },
+        { id: "msg_a", role: "user", time: { created: 1 } },
+        { id: "msg_c" },
+      ],
+    }) as Parameters<typeof readMessagesFromSDK>[0]
+
+    //#when readMessagesFromSDK is called
+    const result = await readMessagesFromSDK(client, sessionID)
+
+    //#then it returns sorted StoredMessageMeta with defaults
+    expect(result).toEqual([
+      { id: "msg_c", sessionID, role: "user", time: { created: 0 } },
+      { id: "msg_a", sessionID, role: "user", time: { created: 1 } },
+      { id: "msg_b", sessionID, role: "assistant", time: { created: 2 } },
+    ])
+  })
+
   it("readParts returns empty array for nonexistent message", () => {
     //#given a message ID that has no stored parts
     //#when readParts is called