Read array tool-result content as text in the WebSearch bridge

src/claude/types.ts

@@ -47,7 +47,8 @@ interface ClaudeImageBlock {
 export interface ClaudeToolResultBlock {
   type: "tool_result"
   tool_use_id: string
-  content: string
+  // Claude Code sends an array when a tool returns more than text, such as an image (#150).
+  content: string | Array<ClaudeTextBlock | ClaudeImageBlock>
   is_error?: boolean
 }
 

src/claude/web-search.ts

@@ -7,6 +7,7 @@ import type {
   ClaudeResponse,
   ClaudeTextBlock,
   ClaudeTool,
+  ClaudeToolResultBlock,
   ClaudeWebSearchResultBlock,
 } from "~/claude/types"
 import type { ClaudeToolNameMapper } from "~/claude/tool-names"
@@ -127,6 +128,23 @@ export const prepareClaudeWebSearchDecisionPayload = (
   }
 }
 
+// A tool result holds a string or an array of blocks, such as text and an image (#150). Each text
+// block keeps its text and any other block is named by its type, so an image reads as "[image]"
+// rather than "[object Object]" (#161). A client can omit the content.
+const toolResultText = (content: ClaudeToolResultBlock["content"] | undefined): string => {
+  if (typeof content === "string") {
+    return content
+  }
+
+  if (!Array.isArray(content)) {
+    return ""
+  }
+
+  return content
+    .map((block) => (block.type === "text" ? block.text : `[${block.type}]`))
+    .join("\n\n")
+}
+
 const textFromMessageContent = (content: ClaudeMessage["content"]): string => {
   if (typeof content === "string") {
     return content
@@ -139,7 +157,7 @@ const textFromMessageContent = (content: ClaudeMessage["content"]): string => {
       }
 
       if (block.type === "tool_result") {
-        return [block.content]
+        return [toolResultText(block.content)]
       }
 
       return []

tests/unit/web-search.test.ts

@@ -731,3 +731,54 @@ test("passes prior conversation history through unchanged", () => {
 
   assert.deepEqual(result.messages.slice(0, -1), history)
 })
+
+// #161: a tool result can hold an array of blocks, such as text and an image. Its text reaches the
+// search request as text, not as "[object Object]".
+test("a tool result with array content reaches the search request as text", async () => {
+  const { withRecordedTransport } = await import("../../src/lib/request-trace")
+  const baseUrl = "https://search-tool-result.invalid"
+  const backend: CopilotModel = { supportedEndpoints: ["/responses"], reasoningEfforts: [] }
+  const config = {
+    ...createConfig(baseUrl),
+    webSearchBackend: "future-search",
+    modelCatalog: { baseUrl, models: new Map([["future-search", backend]]) },
+  }
+  const toolResultPayload: ClaudeMessagesPayload = {
+    ...payload,
+    messages: [
+      { role: "user", content: "List the fixtures." },
+      { role: "assistant", content: [{ type: "tool_use", id: "toolu_1", name: "Glob", input: { pattern: "*.ts" } }] },
+      {
+        role: "user",
+        content: [
+          {
+            type: "tool_result",
+            tool_use_id: "toolu_1",
+            content: [
+              { type: "text", text: "Found 2 files" },
+              { type: "image", source: { type: "base64", media_type: "image/png", data: "iVBORw0KGgo=" } },
+            ],
+          },
+          { type: "text", text: "search the web for copilot docs" },
+        ],
+      },
+    ],
+  }
+  const inputs: Array<string> = []
+
+  await withRecordedTransport({
+    fetch: async (request) => {
+      const { input } = JSON.parse(request.body!) as { input: unknown }
+      assert.equal(typeof input, "string")
+      inputs.push(input as string)
+      return Response.json({ id: "resp_search", model: "future-search", status: "completed", output: [] })
+    },
+    refresh: async () => {},
+  }, async () => {
+    await createClaudeWebSearchExecution(config, toolResultPayload, "copilot docs")
+  })
+
+  assert.equal(inputs.length, 1)
+  assert.ok(inputs[0].includes("user: Found 2 files\n\n[image]\n\nsearch the web for copilot docs"))
+  assert.equal(inputs[0].includes("[object Object]"), false)
+})