refactor(test): reuse sanitize session history fixtures

src/agents/pi-embedded-runner.sanitize-session-history.test-harness.ts

@@ -0,0 +1,58 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { SessionManager } from "@mariozechner/pi-coding-agent";
+import { vi } from "vitest";
+
+export type SessionEntry = { type: string; customType: string; data: unknown };
+
+export function makeModelSnapshotEntry(data: {
+  timestamp?: number;
+  provider: string;
+  modelApi: string;
+  modelId: string;
+}): SessionEntry {
+  return {
+    type: "custom",
+    customType: "model-snapshot",
+    data: {
+      timestamp: data.timestamp ?? Date.now(),
+      provider: data.provider,
+      modelApi: data.modelApi,
+      modelId: data.modelId,
+    },
+  };
+}
+
+export function makeInMemorySessionManager(entries: SessionEntry[]): SessionManager {
+  return {
+    getEntries: vi.fn(() => entries),
+    appendCustomEntry: vi.fn((customType: string, data: unknown) => {
+      entries.push({ type: "custom", customType, data });
+    }),
+  } as unknown as SessionManager;
+}
+
+export function makeReasoningAssistantMessages(opts?: {
+  thinkingSignature?: "object" | "json";
+}): AgentMessage[] {
+  const thinkingSignature: unknown =
+    opts?.thinkingSignature === "json"
+      ? JSON.stringify({ id: "rs_test", type: "reasoning" })
+      : { id: "rs_test", type: "reasoning" };
+
+  // Intentional: we want to build message payloads that can carry non-string
+  // signatures, but core typing currently expects a string.
+  const messages = [
+    {
+      role: "assistant",
+      content: [
+        {
+          type: "thinking",
+          thinking: "reasoning",
+          thinkingSignature,
+        },
+      ],
+    },
+  ];
+
+  return messages as unknown as AgentMessage[];
+}