refactor(server): canonicalize service API (#31049)

packages/tui/test/util/error.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, test } from "bun:test"
+import { errorData, errorFormat, errorMessage } from "../../src/util/error"
+
+describe("util.error", () => {
+  test("formats native Error instances", () => {
+    const err = new Error("boom")
+    expect(errorMessage(err)).toBe("boom")
+    expect(errorFormat(err)).toContain("boom")
+
+    const data = errorData(err)
+    expect(data.type).toBe("Error")
+    expect(data.message).toBe("boom")
+    expect(String(data.formatted)).toContain("boom")
+  })
+
+  test("extracts message from record-like values", () => {
+    const err = { message: "bad input", code: "E_BAD" }
+    expect(errorMessage(err)).toBe("bad input")
+
+    const data = errorData(err)
+    expect(data.message).toBe("bad input")
+    expect(data.code).toBe("E_BAD")
+  })
+
+  test("never returns bare {} for opaque object errors", () => {
+    expect(errorFormat({})).not.toBe("{}")
+    expect(errorFormat({})).toContain("no message")
+
+    class OpaqueError {}
+    const opaque = new OpaqueError()
+    Object.defineProperty(opaque, "secret", { value: "hidden", enumerable: false })
+    expect(errorFormat(opaque)).not.toBe("{}")
+    expect(errorFormat(opaque)).toContain("OpaqueError")
+  })
+
+  test("handles opaque throwables with custom toString", () => {
+    const err = {
+      toString() {
+        return "ResolveMessage: Cannot resolve module"
+      },
+    }
+
+    expect(errorMessage(err)).toBe("ResolveMessage: Cannot resolve module")
+
+    const data = errorData(err)
+    expect(data.message).toBe("ResolveMessage: Cannot resolve module")
+    expect(String(data.formatted)).toContain("ResolveMessage")
+  })
+})