test(agents): centralize AgentMessage fixtures and remove unsafe casts

src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.test.ts

@@ -5,6 +5,7 @@ import {
   sanitizeGoogleTurnOrdering,
   sanitizeSessionMessagesImages,
 } from "./pi-embedded-helpers.js";
+import { castAgentMessages } from "./test-helpers/agent-message-fixtures.js";
 
 let testTimestamp = 1;
 const nextTimestamp = () => testTimestamp++;
@@ -93,7 +94,7 @@ describe("sanitizeSessionMessagesImages", () => {
   });
 
   it("does not synthesize tool call input when missing", async () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_1", name: "read" }],
@@ -111,7 +112,7 @@ describe("sanitizeSessionMessagesImages", () => {
         stopReason: "toolUse",
         timestamp: nextTimestamp(),
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
     const assistant = out[0] as { content?: Array<Record<string, unknown>> };
@@ -122,7 +123,7 @@ describe("sanitizeSessionMessagesImages", () => {
   });
 
   it("removes empty assistant text blocks but preserves tool calls", async () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -143,7 +144,7 @@ describe("sanitizeSessionMessagesImages", () => {
         stopReason: "toolUse",
         timestamp: nextTimestamp(),
       },
-    ] as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
 
@@ -153,7 +154,7 @@ describe("sanitizeSessionMessagesImages", () => {
   });
 
   it("sanitizes tool ids in strict mode (alphanumeric only)", async () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -171,7 +172,7 @@ describe("sanitizeSessionMessagesImages", () => {
         toolUseId: "call_abc|item:123",
         content: [{ type: "text", text: "ok" }],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test", {
       sanitizeToolCallIds: true,
@@ -188,7 +189,7 @@ describe("sanitizeSessionMessagesImages", () => {
   });
 
   it("sanitizes tool IDs in images-only mode when explicitly enabled", async () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_123|fc_456", name: "read", arguments: {} }],
@@ -214,7 +215,7 @@ describe("sanitizeSessionMessagesImages", () => {
         isError: false,
         timestamp: nextTimestamp(),
       },
-    ] as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test", {
       sanitizeMode: "images-only",
@@ -236,7 +237,7 @@ describe("sanitizeSessionMessagesImages", () => {
     }
   });
   it("filters whitespace-only assistant text blocks", async () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -257,7 +258,7 @@ describe("sanitizeSessionMessagesImages", () => {
         stopReason: "stop",
         timestamp: nextTimestamp(),
       },
-    ] as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
 
@@ -266,7 +267,7 @@ describe("sanitizeSessionMessagesImages", () => {
     });
   });
   it("drops assistant messages that only contain empty text", async () => {
-    const input = [
+    const input = castAgentMessages([
       { role: "user", content: "hello", timestamp: nextTimestamp() } satisfies UserMessage,
       {
         role: "assistant",
@@ -285,7 +286,7 @@ describe("sanitizeSessionMessagesImages", () => {
         stopReason: "stop",
         timestamp: nextTimestamp(),
       } satisfies AssistantMessage,
-    ];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
 
@@ -293,7 +294,7 @@ describe("sanitizeSessionMessagesImages", () => {
     expect(out[0]?.role).toBe("user");
   });
   it("keeps empty assistant error messages", async () => {
-    const input = [
+    const input = castAgentMessages([
       { role: "user", content: "hello", timestamp: nextTimestamp() } satisfies UserMessage,
       {
         role: "assistant",
@@ -329,7 +330,7 @@ describe("sanitizeSessionMessagesImages", () => {
         },
         timestamp: nextTimestamp(),
       } satisfies AssistantMessage,
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
 
@@ -360,7 +361,7 @@ describe("sanitizeSessionMessagesImages", () => {
 
   describe("thought_signature stripping", () => {
     it("strips msg_-prefixed thought_signature from assistant message content blocks", async () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [
@@ -372,7 +373,7 @@ describe("sanitizeSessionMessagesImages", () => {
             },
           ],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = await sanitizeSessionMessagesImages(input, "test");
 
@@ -387,19 +388,19 @@ describe("sanitizeSessionMessagesImages", () => {
 
 describe("sanitizeGoogleTurnOrdering", () => {
   it("prepends a synthetic user turn when history starts with assistant", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_1", name: "exec", arguments: {} }],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeGoogleTurnOrdering(input);
     expect(out[0]?.role).toBe("user");
     expect(out[1]?.role).toBe("assistant");
   });
   it("is a no-op when history starts with user", () => {
-    const input = [{ role: "user", content: "hi" }] as unknown as AgentMessage[];
+    const input = castAgentMessages([{ role: "user", content: "hi" }]);
     const out = sanitizeGoogleTurnOrdering(input);
     expect(out).toBe(input);
   });

src/agents/pi-embedded-runner.applygoogleturnorderingfix.test.ts

@@ -2,13 +2,14 @@ import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { SessionManager } from "@mariozechner/pi-coding-agent";
 import { describe, expect, it, vi } from "vitest";
 import { applyGoogleTurnOrderingFix } from "./pi-embedded-runner.js";
+import { castAgentMessage } from "./test-helpers/agent-message-fixtures.js";
 
 describe("applyGoogleTurnOrderingFix", () => {
   const makeAssistantFirst = (): AgentMessage[] => [
-    {
+    castAgentMessage({
       role: "assistant",
       content: [{ type: "toolCall", id: "call_1", name: "exec", arguments: {} }],
-    } as unknown as AgentMessage,
+    }),
   ];
 
   it("prepends a bootstrap once and records a marker for Google models", () => {

src/agents/pi-embedded-runner.openai-tool-id-preservation.test.ts

@@ -5,6 +5,7 @@ import {
   makeModelSnapshotEntry,
 } from "./pi-embedded-runner.sanitize-session-history.test-harness.js";
 import { sanitizeSessionHistory } from "./pi-embedded-runner/google.js";
+import { castAgentMessage } from "./test-helpers/agent-message-fixtures.js";
 
 describe("sanitizeSessionHistory openai tool id preservation", () => {
   const makeSessionManager = () =>
@@ -17,7 +18,7 @@ describe("sanitizeSessionHistory openai tool id preservation", () => {
     ]);
 
   const makeMessages = (withReasoning: boolean): AgentMessage[] => [
-    {
+    castAgentMessage({
       role: "assistant",
       content: [
         ...(withReasoning
@@ -31,14 +32,14 @@ describe("sanitizeSessionHistory openai tool id preservation", () => {
           : []),
         { type: "toolCall", id: "call_123|fc_123", name: "noop", arguments: {} },
       ],
-    } as unknown as AgentMessage,
+    }),
-    {
+    castAgentMessage({
       role: "toolResult",
       toolCallId: "call_123|fc_123",
       toolName: "noop",
       content: [{ type: "text", text: "ok" }],
       isError: false,
-    } as unknown as AgentMessage,
+    }),
   ];
 
   it.each([

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

@@ -15,6 +15,7 @@ import {
   sanitizeWithOpenAIResponses,
   TEST_SESSION_ID,
 } from "./pi-embedded-runner.sanitize-session-history.test-harness.js";
+import { castAgentMessage, castAgentMessages } from "./test-helpers/agent-message-fixtures.js";
 import { makeZeroUsageSnapshot } from "./usage.js";
 
 vi.mock("./pi-embedded-helpers.js", async () => ({
@@ -136,12 +137,12 @@ describe("sanitizeSessionHistory", () => {
   });
 
   const makeCompactionSummaryMessage = (tokensBefore: number, timestamp: string) =>
-    ({
+    castAgentMessage({
       role: "compactionSummary",
       summary: "compressed",
       tokensBefore,
       timestamp,
-    }) as unknown as AgentMessage;
+    });
 
   const sanitizeOpenAIHistory = async (
     messages: AgentMessage[],
@@ -258,7 +259,7 @@ describe("sanitizeSessionHistory", () => {
     setNonGoogleModelApi();
 
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "user",
         content: "forwarded instruction",
         provenance: {
@@ -266,7 +267,7 @@ describe("sanitizeSessionHistory", () => {
           sourceSessionKey: "agent:main:req",
           sourceTool: "sessions_send",
         },
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const result = await sanitizeSessionHistory({
@@ -287,14 +288,14 @@ describe("sanitizeSessionHistory", () => {
   it("drops stale assistant usage snapshots kept before latest compaction summary", async () => {
     vi.mocked(helpers.isGoogleModelApi).mockReturnValue(false);
 
-    const messages = [
+    const messages = castAgentMessages([
       { role: "user", content: "old context" },
       makeAssistantUsageMessage({
         text: "old answer",
         usage: makeUsage(191_919, 2_000, 193_919),
       }),
       makeCompactionSummaryMessage(191_919, new Date().toISOString()),
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = await sanitizeOpenAIHistory(messages);
 
@@ -308,7 +309,7 @@ describe("sanitizeSessionHistory", () => {
   it("preserves fresh assistant usage snapshots created after latest compaction summary", async () => {
     vi.mocked(helpers.isGoogleModelApi).mockReturnValue(false);
 
-    const messages = [
+    const messages = castAgentMessages([
       makeAssistantUsageMessage({
         text: "pre-compaction answer",
         usage: makeUsage(120_000, 3_000, 123_000),
@@ -319,7 +320,7 @@ describe("sanitizeSessionHistory", () => {
         text: "fresh answer",
         usage: makeUsage(1_000, 250, 1_250),
       }),
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = await sanitizeOpenAIHistory(messages);
 
@@ -333,14 +334,14 @@ describe("sanitizeSessionHistory", () => {
     vi.mocked(helpers.isGoogleModelApi).mockReturnValue(false);
 
     const compactionTs = Date.parse("2026-02-26T12:00:00.000Z");
-    const messages = [
+    const messages = castAgentMessages([
       makeCompactionSummaryMessage(191_919, new Date(compactionTs).toISOString()),
       makeAssistantUsageMessage({
         text: "kept pre-compaction answer",
         timestamp: compactionTs - 1_000,
         usage: makeUsage(191_919, 2_000, 193_919),
       }),
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = await sanitizeOpenAIHistory(messages);
 
@@ -354,7 +355,7 @@ describe("sanitizeSessionHistory", () => {
     vi.mocked(helpers.isGoogleModelApi).mockReturnValue(false);
 
     const compactionTs = Date.parse("2026-02-26T12:00:00.000Z");
-    const messages = [
+    const messages = castAgentMessages([
       makeCompactionSummaryMessage(123_000, new Date(compactionTs).toISOString()),
       makeAssistantUsageMessage({
         text: "kept pre-compaction answer",
@@ -367,7 +368,7 @@ describe("sanitizeSessionHistory", () => {
         timestamp: compactionTs + 2_000,
         usage: makeUsage(1_000, 250, 1_250),
       }),
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = await sanitizeOpenAIHistory(messages);
 
@@ -431,13 +432,13 @@ describe("sanitizeSessionHistory", () => {
     {
       name: "missing input or arguments",
       makeMessages: () =>
-        [
+        castAgentMessages([
-          {
+          castAgentMessage({
             role: "assistant",
             content: [{ type: "toolCall", id: "call_1", name: "read" }],
-          } as unknown as AgentMessage,
+          }),
           makeUserMessage("hello"),
-        ] as AgentMessage[],
+        ]),
       overrides: { sessionId: "test-session" } as Partial<
         Parameters<typeof sanitizeOpenAIHistory>[1]
       >,
@@ -445,7 +446,7 @@ describe("sanitizeSessionHistory", () => {
     {
       name: "invalid or overlong names",
       makeMessages: () =>
-        [
+        castAgentMessages([
           makeAssistantMessage(
             [
               {
@@ -464,7 +465,7 @@ describe("sanitizeSessionHistory", () => {
             { stopReason: "toolUse" },
           ),
           makeUserMessage("hello"),
-        ] as AgentMessage[],
+        ]),
       overrides: {} as Partial<Parameters<typeof sanitizeOpenAIHistory>[1]>,
     },
   ])("drops malformed tool calls: $name", async ({ makeMessages, overrides }) => {

src/agents/pi-embedded-runner/run/compaction-timeout.test.ts

@@ -1,5 +1,5 @@
-import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { describe, expect, it } from "vitest";
+import { castAgentMessage } from "../../test-helpers/agent-message-fixtures.js";
 import {
   selectCompactionTimeoutSnapshot,
   shouldFlagCompactionTimeout,
@@ -32,8 +32,8 @@ describe("compaction-timeout helpers", () => {
   });
 
   it("uses pre-compaction snapshot when compaction timeout occurs", () => {
-    const pre = [{ role: "assistant", content: "pre" } as unknown as AgentMessage] as const;
+    const pre = [castAgentMessage({ role: "assistant", content: "pre" })] as const;
-    const current = [{ role: "assistant", content: "current" } as unknown as AgentMessage] as const;
+    const current = [castAgentMessage({ role: "assistant", content: "current" })] as const;
     const selected = selectCompactionTimeoutSnapshot({
       timedOutDuringCompaction: true,
       preCompactionSnapshot: [...pre],
@@ -47,7 +47,7 @@ describe("compaction-timeout helpers", () => {
   });
 
   it("falls back to current snapshot when pre-compaction snapshot is unavailable", () => {
-    const current = [{ role: "assistant", content: "current" } as unknown as AgentMessage] as const;
+    const current = [castAgentMessage({ role: "assistant", content: "current" })] as const;
     const selected = selectCompactionTimeoutSnapshot({
       timedOutDuringCompaction: true,
       preCompactionSnapshot: null,

src/agents/pi-embedded-runner/run/history-image-prune.test.ts

@@ -1,6 +1,7 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { ImageContent } from "@mariozechner/pi-ai";
 import { describe, expect, it } from "vitest";
+import { castAgentMessage } from "../../test-helpers/agent-message-fixtures.js";
 import { PRUNED_HISTORY_IMAGE_MARKER, pruneProcessedHistoryImages } from "./history-image-prune.js";
 
 describe("pruneProcessedHistoryImages", () => {
@@ -8,14 +9,14 @@ describe("pruneProcessedHistoryImages", () => {
 
   it("prunes image blocks from user messages that already have assistant replies", () => {
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "user",
         content: [{ type: "text", text: "See /tmp/photo.png" }, { ...image }],
-      } as AgentMessage,
+      }),
-      {
+      castAgentMessage({
         role: "assistant",
         content: "got it",
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const didMutate = pruneProcessedHistoryImages(messages);
@@ -31,10 +32,10 @@ describe("pruneProcessedHistoryImages", () => {
 
   it("does not prune latest user message when no assistant response exists yet", () => {
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "user",
         content: [{ type: "text", text: "See /tmp/photo.png" }, { ...image }],
-      } as AgentMessage,
+      }),
     ];
 
     const didMutate = pruneProcessedHistoryImages(messages);
@@ -50,10 +51,10 @@ describe("pruneProcessedHistoryImages", () => {
 
   it("does not change messages when no assistant turn exists", () => {
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "user",
         content: "noop",
-      } as AgentMessage,
+      }),
     ];
 
     const didMutate = pruneProcessedHistoryImages(messages);

src/agents/pi-embedded-runner/thinking.test.ts

@@ -1,15 +1,16 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { describe, expect, it } from "vitest";
+import { castAgentMessage } from "../test-helpers/agent-message-fixtures.js";
 import { dropThinkingBlocks, isAssistantMessageWithContent } from "./thinking.js";
 
 describe("isAssistantMessageWithContent", () => {
   it("accepts assistant messages with array content and rejects others", () => {
-    const assistant = {
+    const assistant = castAgentMessage({
       role: "assistant",
       content: [{ type: "text", text: "ok" }],
-    } as AgentMessage;
+    });
-    const user = { role: "user", content: "hi" } as AgentMessage;
+    const user = castAgentMessage({ role: "user", content: "hi" });
-    const malformed = { role: "assistant", content: "not-array" } as unknown as AgentMessage;
+    const malformed = castAgentMessage({ role: "assistant", content: "not-array" });
 
     expect(isAssistantMessageWithContent(assistant)).toBe(true);
     expect(isAssistantMessageWithContent(user)).toBe(false);
@@ -20,8 +21,8 @@ describe("isAssistantMessageWithContent", () => {
 describe("dropThinkingBlocks", () => {
   it("returns the original reference when no thinking blocks are present", () => {
     const messages: AgentMessage[] = [
-      { role: "user", content: "hello" } as AgentMessage,
+      castAgentMessage({ role: "user", content: "hello" }),
-      { role: "assistant", content: [{ type: "text", text: "world" }] } as AgentMessage,
+      castAgentMessage({ role: "assistant", content: [{ type: "text", text: "world" }] }),
     ];
 
     const result = dropThinkingBlocks(messages);
@@ -30,13 +31,13 @@ describe("dropThinkingBlocks", () => {
 
   it("drops thinking blocks while preserving non-thinking assistant content", () => {
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "assistant",
         content: [
           { type: "thinking", thinking: "internal" },
           { type: "text", text: "final" },
         ],
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const result = dropThinkingBlocks(messages);
@@ -47,10 +48,10 @@ describe("dropThinkingBlocks", () => {
 
   it("keeps assistant turn structure when all content blocks were thinking", () => {
     const messages: AgentMessage[] = [
-      {
+      castAgentMessage({
         role: "assistant",
         content: [{ type: "thinking", thinking: "internal-only" }],
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const result = dropThinkingBlocks(messages);

src/agents/pi-embedded-runner/tool-result-context-guard.test.ts

@@ -1,5 +1,6 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { describe, expect, it } from "vitest";
+import { castAgentMessage } from "../test-helpers/agent-message-fixtures.js";
 import {
   CONTEXT_LIMIT_TRUNCATION_NOTICE,
   PREEMPTIVE_TOOL_RESULT_COMPACTION_PLACEHOLDER,
@@ -7,35 +8,35 @@ import {
 } from "./tool-result-context-guard.js";
 
 function makeUser(text: string): AgentMessage {
-  return {
+  return castAgentMessage({
     role: "user",
     content: text,
     timestamp: Date.now(),
-  } as unknown as AgentMessage;
+  });
 }
 
 function makeToolResult(id: string, text: string): AgentMessage {
-  return {
+  return castAgentMessage({
     role: "toolResult",
     toolCallId: id,
     toolName: "read",
     content: [{ type: "text", text }],
     isError: false,
     timestamp: Date.now(),
-  } as unknown as AgentMessage;
+  });
 }
 
 function makeLegacyToolResult(id: string, text: string): AgentMessage {
-  return {
+  return castAgentMessage({
     role: "tool",
     tool_call_id: id,
     tool_name: "read",
     content: text,
-  } as unknown as AgentMessage;
+  });
 }
 
 function makeToolResultWithDetails(id: string, text: string, detailText: string): AgentMessage {
-  return {
+  return castAgentMessage({
     role: "toolResult",
     toolCallId: id,
     toolName: "read",
@@ -49,7 +50,7 @@ function makeToolResultWithDetails(id: string, text: string, detailText: string)
     },
     isError: false,
     timestamp: Date.now(),
-  } as unknown as AgentMessage;
+  });
 }
 
 function getToolResultText(msg: AgentMessage): string {
@@ -199,11 +200,10 @@ describe("installToolResultContextGuard", () => {
 
   it("wraps an existing transformContext and guards the transformed output", async () => {
     const agent = makeGuardableAgent((messages) => {
-      return messages.map(
+      return messages.map((msg) =>
-        (msg) =>
+        castAgentMessage({
-          ({
+          ...(msg as unknown as Record<string, unknown>),
-            ...(msg as unknown as Record<string, unknown>),
+        }),
-          }) as unknown as AgentMessage,
       );
     });
     const contextForNextCall = makeTwoToolResultOverflowContext();
@@ -254,10 +254,10 @@ describe("installToolResultContextGuard", () => {
 
     await agent.transformContext?.(contextForNextCall, new AbortController().signal);
 
-    const oldResult = contextForNextCall[1] as unknown as {
+    const oldResult = contextForNextCall[1] as {
       details?: unknown;
     };
-    const newResult = contextForNextCall[2] as unknown as {
+    const newResult = contextForNextCall[2] as {
       details?: unknown;
     };
     const oldResultText = getToolResultText(contextForNextCall[1]);

src/agents/pi-extensions/compaction-safeguard.test.ts

@@ -5,6 +5,7 @@ import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { Api, Model } from "@mariozechner/pi-ai";
 import type { ExtensionAPI, ExtensionContext } from "@mariozechner/pi-coding-agent";
 import { describe, expect, it, vi } from "vitest";
+import { castAgentMessage } from "../test-helpers/agent-message-fixtures.js";
 import {
   getCompactionSafeguardRuntime,
   setCompactionSafeguardRuntime,
@@ -218,11 +219,11 @@ describe("computeAdaptiveChunkRatio", () => {
     // Small messages: 1000 tokens each, well under 10% of context
     const messages: AgentMessage[] = [
       { role: "user", content: "x".repeat(1000), timestamp: Date.now() },
-      {
+      castAgentMessage({
         role: "assistant",
         content: [{ type: "text", text: "y".repeat(1000) }],
         timestamp: Date.now(),
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const ratio = computeAdaptiveChunkRatio(messages, CONTEXT_WINDOW);
@@ -233,11 +234,11 @@ describe("computeAdaptiveChunkRatio", () => {
     // Large messages: ~50K tokens each (25% of context)
     const messages: AgentMessage[] = [
       { role: "user", content: "x".repeat(50_000 * 4), timestamp: Date.now() },
-      {
+      castAgentMessage({
         role: "assistant",
         content: [{ type: "text", text: "y".repeat(50_000 * 4) }],
         timestamp: Date.now(),
-      } as unknown as AgentMessage,
+      }),
     ];
 
     const ratio = computeAdaptiveChunkRatio(messages, CONTEXT_WINDOW);

src/agents/session-tool-result-guard.test.ts

@@ -2,6 +2,7 @@ import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { SessionManager } from "@mariozechner/pi-coding-agent";
 import { describe, expect, it } from "vitest";
 import { installSessionToolResultGuard } from "./session-tool-result-guard.js";
+import { castAgentMessage } from "./test-helpers/agent-message-fixtures.js";
 
 type AppendMessage = Parameters<SessionManager["appendMessage"]>[0];
 
@@ -388,10 +389,10 @@ describe("installSessionToolResultGuard", () => {
           return undefined;
         }
         return {
-          message: {
+          message: castAgentMessage({
             ...(message as unknown as Record<string, unknown>),
             content: [{ type: "text", text: "rewritten by hook" }],
-          } as unknown as AgentMessage,
+          }),
         };
       },
     });
@@ -425,10 +426,10 @@ describe("installSessionToolResultGuard", () => {
     installSessionToolResultGuard(sm, {
       transformMessageForPersistence: (message) =>
         (message as { role?: string }).role === "user"
-          ? ({
+          ? castAgentMessage({
               ...(message as unknown as Record<string, unknown>),
               provenance: { kind: "inter_session", sourceTool: "sessions_send" },
-            } as unknown as AgentMessage)
+            })
           : message,
     });
 

src/agents/session-transcript-repair.attachments.test.ts

@@ -1,9 +1,10 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { describe, it, expect } from "vitest";
 import { sanitizeToolCallInputs } from "./session-transcript-repair.js";
+import { castAgentMessage, castAgentMessages } from "./test-helpers/agent-message-fixtures.js";
 
 function mkSessionsSpawnToolCall(content: string): AgentMessage {
-  return {
+  return castAgentMessage({
     role: "assistant",
     content: [
       {
@@ -23,7 +24,7 @@ function mkSessionsSpawnToolCall(content: string): AgentMessage {
       },
     ],
     timestamp: Date.now(),
-  } as unknown as AgentMessage;
+  });
 }
 
 describe("sanitizeToolCallInputs redacts sessions_spawn attachments", () => {
@@ -44,7 +45,7 @@ describe("sanitizeToolCallInputs redacts sessions_spawn attachments", () => {
 
   it("redacts attachments content from tool input payloads too", () => {
     const secret = "INPUT_SECRET_SHOULD_NOT_PERSIST";
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -59,7 +60,7 @@ describe("sanitizeToolCallInputs redacts sessions_spawn attachments", () => {
           },
         ],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolCallInputs(input);
     const msg = out[0] as { content?: unknown[] };

src/agents/session-transcript-repair.test.ts

@@ -6,6 +6,7 @@ import {
   repairToolUseResultPairing,
   stripToolResultDetails,
 } from "./session-transcript-repair.js";
+import { castAgentMessage, castAgentMessages } from "./test-helpers/agent-message-fixtures.js";
 
 const TOOL_CALL_BLOCK_TYPES = new Set(["toolCall", "toolUse", "functionCall"]);
 
@@ -25,7 +26,7 @@ describe("sanitizeToolUseResultPairing", () => {
     middleMessage?: unknown;
     secondText?: string;
   }): AgentMessage[] =>
-    [
+    castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_1", name: "read", arguments: {} }],
@@ -37,7 +38,7 @@ describe("sanitizeToolUseResultPairing", () => {
         content: [{ type: "text", text: "first" }],
         isError: false,
       },
-      ...(opts?.middleMessage ? [opts.middleMessage as AgentMessage] : []),
+      ...(opts?.middleMessage ? [castAgentMessage(opts.middleMessage)] : []),
       {
         role: "toolResult",
         toolCallId: "call_1",
@@ -45,10 +46,10 @@ describe("sanitizeToolUseResultPairing", () => {
         content: [{ type: "text", text: opts?.secondText ?? "second" }],
         isError: false,
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
   it("moves tool results directly after tool calls and inserts missing results", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -64,7 +65,7 @@ describe("sanitizeToolUseResultPairing", () => {
         content: [{ type: "text", text: "ok" }],
         isError: false,
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolUseResultPairing(input);
     expect(out[0]?.role).toBe("assistant");
@@ -76,7 +77,7 @@ describe("sanitizeToolUseResultPairing", () => {
   });
 
   it("repairs blank tool result names from matching tool calls", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_1", name: "read", arguments: {} }],
@@ -88,7 +89,7 @@ describe("sanitizeToolUseResultPairing", () => {
         content: [{ type: "text", text: "ok" }],
         isError: false,
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolUseResultPairing(input);
     const toolResult = out.find((message) => message.role === "toolResult") as {
@@ -99,10 +100,10 @@ describe("sanitizeToolUseResultPairing", () => {
   });
 
   it("drops duplicate tool results for the same id within a span", () => {
-    const input = [
+    const input = castAgentMessages([
       ...buildDuplicateToolResultInput(),
       { role: "user", content: "ok" },
-    ] as AgentMessage[];
+    ]);
 
     const out = sanitizeToolUseResultPairing(input);
     expect(out.filter((m) => m.role === "toolResult")).toHaveLength(1);
@@ -123,7 +124,7 @@ describe("sanitizeToolUseResultPairing", () => {
   });
 
   it("drops orphan tool results that do not match any tool call", () => {
-    const input = [
+    const input = castAgentMessages([
       { role: "user", content: "hello" },
       {
         role: "toolResult",
@@ -136,7 +137,7 @@ describe("sanitizeToolUseResultPairing", () => {
         role: "assistant",
         content: [{ type: "text", text: "ok" }],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolUseResultPairing(input);
     expect(out.some((m) => m.role === "toolResult")).toBe(false);
@@ -147,14 +148,14 @@ describe("sanitizeToolUseResultPairing", () => {
     // When an assistant message has stopReason: "error", its tool_use blocks may be
     // incomplete/malformed. We should NOT create synthetic tool_results for them,
     // as this causes API 400 errors: "unexpected tool_use_id found in tool_result blocks"
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_error", name: "exec", arguments: {} }],
         stopReason: "error",
       },
       { role: "user", content: "something went wrong" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = repairToolUseResultPairing(input);
 
@@ -169,14 +170,14 @@ describe("sanitizeToolUseResultPairing", () => {
   it("skips tool call extraction for assistant messages with stopReason 'aborted'", () => {
     // When a request is aborted mid-stream, the assistant message may have incomplete
     // tool_use blocks (with partialJson). We should NOT create synthetic tool_results.
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_aborted", name: "Bash", arguments: {} }],
         stopReason: "aborted",
       },
       { role: "user", content: "retrying after abort" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = repairToolUseResultPairing(input);
 
@@ -190,14 +191,14 @@ describe("sanitizeToolUseResultPairing", () => {
 
   it("still repairs tool results for normal assistant messages with stopReason 'toolUse'", () => {
     // Normal tool calls (stopReason: "toolUse" or "stop") should still be repaired
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_normal", name: "read", arguments: {} }],
         stopReason: "toolUse",
       },
       { role: "user", content: "user message" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = repairToolUseResultPairing(input);
 
@@ -210,7 +211,7 @@ describe("sanitizeToolUseResultPairing", () => {
     // When an assistant message is aborted, any tool results that follow should be
     // dropped as orphans (since we skip extracting tool calls from aborted messages).
     // This addresses the edge case where a partial tool result was persisted before abort.
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_aborted", name: "exec", arguments: {} }],
@@ -224,7 +225,7 @@ describe("sanitizeToolUseResultPairing", () => {
         isError: false,
       },
       { role: "user", content: "retrying" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const result = repairToolUseResultPairing(input);
 
@@ -244,12 +245,12 @@ describe("sanitizeToolCallInputs", () => {
     options?: Parameters<typeof sanitizeToolCallInputs>[1],
   ) {
     return sanitizeToolCallInputs(
-      [
+      castAgentMessages([
         {
           role: "assistant",
           content,
         },
-      ] as unknown as AgentMessage[],
+      ]),
       options,
     );
   }
@@ -262,13 +263,13 @@ describe("sanitizeToolCallInputs", () => {
   }
 
   it("drops tool calls missing input or arguments", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [{ type: "toolCall", id: "call_1", name: "read" }],
       },
       { role: "user", content: "hello" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolCallInputs(input);
     expect(out.map((m) => m.role)).toEqual(["user"]);
@@ -325,7 +326,7 @@ describe("sanitizeToolCallInputs", () => {
   });
 
   it("keeps valid tool calls and preserves text blocks", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -334,7 +335,7 @@ describe("sanitizeToolCallInputs", () => {
           { type: "toolCall", id: "call_drop", name: "read" },
         ],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolCallInputs(input);
     const assistant = out[0] as Extract<AgentMessage, { role: "assistant" }>;
@@ -384,7 +385,7 @@ describe("sanitizeToolCallInputs", () => {
   });
 
   it("preserves toolUse input shape for sessions_spawn when no attachments are present", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -396,7 +397,7 @@ describe("sanitizeToolCallInputs", () => {
           },
         ],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolCallInputs(input);
     const toolCalls = getAssistantToolCallBlocks(out) as Array<Record<string, unknown>>;
@@ -408,7 +409,7 @@ describe("sanitizeToolCallInputs", () => {
   });
 
   it("redacts sessions_spawn attachments for mixed-case and padded tool names", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "assistant",
         content: [
@@ -423,7 +424,7 @@ describe("sanitizeToolCallInputs", () => {
           },
         ],
       },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = sanitizeToolCallInputs(input);
     const toolCalls = getAssistantToolCallBlocks(out) as Array<Record<string, unknown>>;
@@ -448,7 +449,7 @@ describe("sanitizeToolCallInputs", () => {
 
 describe("stripToolResultDetails", () => {
   it("removes details only from toolResult messages", () => {
-    const input = [
+    const input = castAgentMessages([
       {
         role: "toolResult",
         toolCallId: "call_1",
@@ -458,7 +459,7 @@ describe("stripToolResultDetails", () => {
       },
       { role: "assistant", content: [{ type: "text", text: "keep me" }], details: { no: "touch" } },
       { role: "user", content: "hello" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = stripToolResultDetails(input) as unknown as Array<Record<string, unknown>>;
 
@@ -472,7 +473,7 @@ describe("stripToolResultDetails", () => {
   });
 
   it("returns the same array reference when there are no toolResult details", () => {
-    const input = [
+    const input = castAgentMessages([
       { role: "assistant", content: [{ type: "text", text: "a" }] },
       {
         role: "toolResult",
@@ -481,7 +482,7 @@ describe("stripToolResultDetails", () => {
         content: [{ type: "text", text: "ok" }],
       },
       { role: "user", content: "b" },
-    ] as unknown as AgentMessage[];
+    ]);
 
     const out = stripToolResultDetails(input);
     expect(out).toBe(input);

src/agents/test-helpers/agent-message-fixtures.ts

@@ -0,0 +1,66 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { AssistantMessage, ToolResultMessage, Usage, UserMessage } from "@mariozechner/pi-ai";
+
+const ZERO_USAGE: Usage = {
+  input: 0,
+  output: 0,
+  cacheRead: 0,
+  cacheWrite: 0,
+  totalTokens: 0,
+  cost: {
+    input: 0,
+    output: 0,
+    cacheRead: 0,
+    cacheWrite: 0,
+    total: 0,
+  },
+};
+
+export function castAgentMessage(message: unknown): AgentMessage {
+  return message as AgentMessage;
+}
+
+export function castAgentMessages(messages: unknown[]): AgentMessage[] {
+  return messages as AgentMessage[];
+}
+
+export function makeAgentUserMessage(
+  overrides: Partial<UserMessage> & Pick<UserMessage, "content">,
+): UserMessage {
+  return {
+    role: "user",
+    timestamp: 0,
+    ...overrides,
+  };
+}
+
+export function makeAgentAssistantMessage(
+  overrides: Partial<AssistantMessage> & Pick<AssistantMessage, "content">,
+): AssistantMessage {
+  return {
+    role: "assistant",
+    api: "openai-responses",
+    provider: "openai",
+    model: "test-model",
+    usage: ZERO_USAGE,
+    stopReason: "stop",
+    timestamp: 0,
+    ...overrides,
+  };
+}
+
+export function makeAgentToolResultMessage(
+  overrides: Partial<ToolResultMessage> &
+    Pick<ToolResultMessage, "toolCallId" | "toolName" | "content">,
+): ToolResultMessage {
+  const { toolCallId, toolName, content, ...rest } = overrides;
+  return {
+    role: "toolResult",
+    toolCallId,
+    toolName,
+    content,
+    isError: false,
+    timestamp: 0,
+    ...rest,
+  };
+}

src/agents/tool-call-id.test.ts

@@ -1,12 +1,13 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { describe, expect, it } from "vitest";
+import { castAgentMessages } from "./test-helpers/agent-message-fixtures.js";
 import {
   isValidCloudCodeAssistToolId,
   sanitizeToolCallIdsForCloudCodeAssist,
 } from "./tool-call-id.js";
 
 const buildDuplicateIdCollisionInput = () =>
-  [
+  castAgentMessages([
     {
       role: "assistant",
       content: [
@@ -26,7 +27,7 @@ const buildDuplicateIdCollisionInput = () =>
       toolName: "read",
       content: [{ type: "text", text: "two" }],
     },
-  ] as unknown as AgentMessage[];
+  ]);
 
 function expectCollisionIdsRemainDistinct(
   out: AgentMessage[],
@@ -65,7 +66,7 @@ function expectSingleToolCallRewrite(
 describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
   describe("strict mode (default)", () => {
     it("is a no-op for already-valid non-colliding IDs", () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [{ type: "toolCall", id: "call1", name: "read", arguments: {} }],
@@ -76,14 +77,14 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "read",
           content: [{ type: "text", text: "ok" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input);
       expect(out).toBe(input);
     });
 
     it("strips non-alphanumeric characters from tool call IDs", () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [{ type: "toolCall", id: "call|item:123", name: "read", arguments: {} }],
@@ -94,7 +95,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "read",
           content: [{ type: "text", text: "ok" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input);
       expect(out).not.toBe(input);
@@ -113,7 +114,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
     it("caps tool call IDs at 40 chars while preserving uniqueness", () => {
       const longA = `call_${"a".repeat(60)}`;
       const longB = `call_${"a".repeat(59)}b`;
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [
@@ -133,7 +134,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "read",
           content: [{ type: "text", text: "two" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input);
       const { aId, bId } = expectCollisionIdsRemainDistinct(out, "strict");
@@ -144,7 +145,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
 
   describe("strict mode (alphanumeric only)", () => {
     it("strips underscores and hyphens from tool call IDs", () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [
@@ -162,7 +163,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "login",
           content: [{ type: "text", text: "ok" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input, "strict");
       expect(out).not.toBe(input);
@@ -184,7 +185,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
 
   describe("strict9 mode (Mistral tool call IDs)", () => {
     it("is a no-op for already-valid 9-char alphanumeric IDs", () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [{ type: "toolCall", id: "abc123XYZ", name: "read", arguments: {} }],
@@ -195,14 +196,14 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "read",
           content: [{ type: "text", text: "ok" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input, "strict9");
       expect(out).toBe(input);
     });
 
     it("enforces alphanumeric IDs with length 9", () => {
-      const input = [
+      const input = castAgentMessages([
         {
           role: "assistant",
           content: [
@@ -222,7 +223,7 @@ describe("sanitizeToolCallIdsForCloudCodeAssist", () => {
           toolName: "read",
           content: [{ type: "text", text: "two" }],
         },
-      ] as unknown as AgentMessage[];
+      ]);
 
       const out = sanitizeToolCallIdsForCloudCodeAssist(input, "strict9");
       expect(out).not.toBe(input);