Fix model fallback across main/background/sync agents

src/shared/model-error-classifier.test.ts

@@ -0,0 +1,76 @@
+import { describe, expect, test, beforeEach, afterEach, spyOn } from "bun:test"
+
+import { mkdirSync, rmSync, writeFileSync, existsSync } from "node:fs"
+import { join } from "node:path"
+import * as dataPath from "./data-path"
+import { shouldRetryError, selectFallbackProvider } from "./model-error-classifier"
+
+const TEST_CACHE_DIR = join(import.meta.dir, "__test-cache__")
+
+describe("model-error-classifier", () => {
+  let cacheDirSpy: ReturnType<typeof spyOn>
+
+  beforeEach(() => {
+    cacheDirSpy = spyOn(dataPath, "getOmoOpenCodeCacheDir").mockReturnValue(TEST_CACHE_DIR)
+    if (existsSync(TEST_CACHE_DIR)) {
+      rmSync(TEST_CACHE_DIR, { recursive: true })
+    }
+    mkdirSync(TEST_CACHE_DIR, { recursive: true })
+  })
+
+  afterEach(() => {
+    cacheDirSpy.mockRestore()
+    if (existsSync(TEST_CACHE_DIR)) {
+      rmSync(TEST_CACHE_DIR, { recursive: true })
+    }
+  })
+
+  test("treats overloaded retry messages as retryable", () => {
+    //#given
+    const error = { message: "Provider is overloaded" }
+
+    //#when
+    const result = shouldRetryError(error)
+
+    //#then
+    expect(result).toBe(true)
+  })
+
+  test("selectFallbackProvider prefers first connected provider in preference order", () => {
+    //#given
+    writeFileSync(
+      join(TEST_CACHE_DIR, "connected-providers.json"),
+      JSON.stringify({ connected: ["quotio", "nvidia"], updatedAt: new Date().toISOString() }, null, 2),
+    )
+
+    //#when
+    const provider = selectFallbackProvider(["quotio", "nvidia"], "nvidia")
+
+    //#then
+    expect(provider).toBe("quotio")
+  })
+
+  test("selectFallbackProvider falls back to next connected provider when first is disconnected", () => {
+    //#given
+    writeFileSync(
+      join(TEST_CACHE_DIR, "connected-providers.json"),
+      JSON.stringify({ connected: ["nvidia"], updatedAt: new Date().toISOString() }, null, 2),
+    )
+
+    //#when
+    const provider = selectFallbackProvider(["quotio", "nvidia"])
+
+    //#then
+    expect(provider).toBe("nvidia")
+  })
+
+  test("selectFallbackProvider uses provider preference order when cache is missing", () => {
+    //#given - no cache file
+
+    //#when
+    const provider = selectFallbackProvider(["quotio", "nvidia"], "nvidia")
+
+    //#then
+    expect(provider).toBe("quotio")
+  })
+})