test(agents): fix context-pruning malformed-block fixture typing

src/agents/pi-extensions/context-pruning/pruner.test.ts

@@ -1,60 +1,111 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { ExtensionContext } from "@mariozechner/pi-coding-agent";
 import { describe, expect, it } from "vitest";
 import { pruneContextMessages } from "./pruner.js";
 import { DEFAULT_CONTEXT_PRUNING_SETTINGS } from "./settings.js";
 
-const MODEL = { contextWindow: 1_000_000 };
+type AssistantMessage = Extract<AgentMessage, { role: "assistant" }>;
+type AssistantContentBlock = AssistantMessage["content"][number];
+
+const CONTEXT_WINDOW_1M = {
+  model: { contextWindow: 1_000_000 },
+} as unknown as ExtensionContext;
+
+function makeUser(text: string): AgentMessage {
+  return {
+    role: "user",
+    content: text,
+    timestamp: Date.now(),
+  };
+}
+
+function makeAssistant(content: AssistantMessage["content"]): AgentMessage {
+  return {
+    role: "assistant",
+    content,
+    api: "openai-responses",
+    provider: "openai",
+    model: "test-model",
+    usage: {
+      input: 1,
+      output: 1,
+      cacheRead: 0,
+      cacheWrite: 0,
+      totalTokens: 2,
+      cost: {
+        input: 0,
+        output: 0,
+        cacheRead: 0,
+        cacheWrite: 0,
+        total: 0,
+      },
+    },
+    stopReason: "stop",
+    timestamp: Date.now(),
+  };
+}
 
 describe("pruneContextMessages", () => {
   it("does not crash on assistant message with malformed thinking block (missing thinking string)", () => {
     const messages: AgentMessage[] = [
-      { role: "user", content: "hello" },
-      {
-        role: "assistant",
-        content: [{ type: "thinking" } as never, { type: "text", text: "ok" }],
-      },
+      makeUser("hello"),
+      makeAssistant([
+        { type: "thinking" } as unknown as AssistantContentBlock,
+        { type: "text", text: "ok" },
+      ]),
     ];
     expect(() =>
       pruneContextMessages({
         messages,
         settings: DEFAULT_CONTEXT_PRUNING_SETTINGS,
-        ctx: { model: MODEL },
+        ctx: CONTEXT_WINDOW_1M,
       }),
     ).not.toThrow();
   });
 
   it("does not crash on assistant message with null content entries", () => {
     const messages: AgentMessage[] = [
-      { role: "user", content: "hello" },
-      {
-        role: "assistant",
-        content: [null as never, { type: "text", text: "world" }],
-      },
+      makeUser("hello"),
+      makeAssistant([null as unknown as AssistantContentBlock, { type: "text", text: "world" }]),
     ];
     expect(() =>
       pruneContextMessages({
         messages,
         settings: DEFAULT_CONTEXT_PRUNING_SETTINGS,
-        ctx: { model: MODEL },
+        ctx: CONTEXT_WINDOW_1M,
+      }),
+    ).not.toThrow();
+  });
+
+  it("does not crash on assistant message with malformed text block (missing text string)", () => {
+    const messages: AgentMessage[] = [
+      makeUser("hello"),
+      makeAssistant([
+        { type: "text" } as unknown as AssistantContentBlock,
+        { type: "thinking", thinking: "still fine" },
+      ]),
+    ];
+    expect(() =>
+      pruneContextMessages({
+        messages,
+        settings: DEFAULT_CONTEXT_PRUNING_SETTINGS,
+        ctx: CONTEXT_WINDOW_1M,
       }),
     ).not.toThrow();
   });
 
   it("handles well-formed thinking blocks correctly", () => {
     const messages: AgentMessage[] = [
-      { role: "user", content: "hello" },
-      {
-        role: "assistant",
-        content: [
-          { type: "thinking", thinking: "let me think" },
-          { type: "text", text: "here is the answer" },
-        ],
-      },
+      makeUser("hello"),
+      makeAssistant([
+        { type: "thinking", thinking: "let me think" },
+        { type: "text", text: "here is the answer" },
+      ]),
     ];
     const result = pruneContextMessages({
       messages,
       settings: DEFAULT_CONTEXT_PRUNING_SETTINGS,
-      ctx: { model: MODEL },
+      ctx: CONTEXT_WINDOW_1M,
     });
     expect(result).toHaveLength(2);
   });