feat: enrich subtask handoff with structured context summaries

Phase 1 of #12330 - improves context handoff visibility between
parent and child tasks during delegation.

Changes:
- Add SubtaskSummary type to @roo-code/types for structured handoff data
- Create buildSubtaskSummary utility that extracts files modified/read,
  commands executed, tool usage, and todo stats from task history
- Modify AttemptCompletionTool to build structured summary on completion
- Update reopenParentFromDelegation to format enriched API history text
  so the parent LLM gets better context about what the subtask did
- Update ChatRow UI to render structured summaries with mode badge,
  file lists, command lists, and todo progress
- Add i18n translation keys for new UI elements
- Add 19 tests for buildSubtaskSummary and formatSubtaskSummaryForApi
- Backward compatible: plain-text summaries still work as before

Author: roomote

packages/types/src/history.ts

@@ -29,3 +29,34 @@ export const historyItemSchema = z.object({
 })
 
 export type HistoryItem = z.infer<typeof historyItemSchema>
+
+/**
+ * SubtaskSummary
+ *
+ * Structured metadata produced when a subtask completes via attempt_completion
+ * and hands off context back to its parent task. This enriches the handoff
+ * with visibility into what the subtask actually did.
+ */
+export const subtaskSummarySchema = z.object({
+	/** The completion result text from attempt_completion */
+	result: z.string(),
+	/** Mode slug the subtask ran in (e.g. "code", "architect") */
+	mode: z.string().optional(),
+	/** Files that were created or modified (write_to_file, apply_diff, insert_content) */
+	filesModified: z.array(z.string()).optional(),
+	/** Files that were read during the subtask */
+	filesRead: z.array(z.string()).optional(),
+	/** Shell commands that were executed */
+	commandsExecuted: z.array(z.string()).optional(),
+	/** Summary of tool usage counts: tool name -> number of attempts */
+	toolUsageSummary: z.record(z.string(), z.number()).optional(),
+	/** Todo list status at completion: [completed, total] */
+	todoStats: z
+		.object({
+			completed: z.number(),
+			total: z.number(),
+		})
+		.optional(),
+})
+
+export type SubtaskSummary = z.infer<typeof subtaskSummarySchema>

src/core/task/__tests__/buildSubtaskSummary.spec.ts

@@ -0,0 +1,308 @@
+import { buildSubtaskSummary, formatSubtaskSummaryForApi, type SubtaskContext } from "../buildSubtaskSummary"
+
+function createContext(overrides: Partial<SubtaskContext> = {}): SubtaskContext {
+	return {
+		apiConversationHistory: [],
+		toolUsage: {},
+		todoList: undefined,
+		taskMode: "code",
+		...overrides,
+	}
+}
+
+describe("buildSubtaskSummary", () => {
+	it("should return a minimal summary with just result and mode", () => {
+		const context = createContext()
+		const summary = buildSubtaskSummary(context, "Task completed successfully")
+
+		expect(summary.result).toBe("Task completed successfully")
+		expect(summary.mode).toBe("code")
+		expect(summary.filesModified).toBeUndefined()
+		expect(summary.filesRead).toBeUndefined()
+		expect(summary.commandsExecuted).toBeUndefined()
+		expect(summary.toolUsageSummary).toBeUndefined()
+		expect(summary.todoStats).toBeUndefined()
+	})
+
+	it("should extract files modified from write_to_file tool_use blocks", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_1",
+							name: "write_to_file",
+							input: { path: "src/index.ts", content: "hello" },
+						},
+					],
+				},
+				{
+					role: "user",
+					content: [{ type: "tool_result", tool_use_id: "toolu_1", content: "ok" }],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesModified).toEqual(["src/index.ts"])
+	})
+
+	it("should extract files modified from apply_diff tool_use blocks", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_2",
+							name: "apply_diff",
+							input: { path: "src/utils.ts", diff: "--- a\n+++ b" },
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesModified).toEqual(["src/utils.ts"])
+	})
+
+	it("should extract files read from read_file tool_use blocks", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_3",
+							name: "read_file",
+							input: { path: "package.json" },
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesRead).toEqual(["package.json"])
+	})
+
+	it("should extract commands from execute_command tool_use blocks", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_4",
+							name: "execute_command",
+							input: { command: "npm test" },
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.commandsExecuted).toEqual(["npm test"])
+	})
+
+	it("should truncate very long commands", () => {
+		const longCmd = "a".repeat(200)
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_5",
+							name: "execute_command",
+							input: { command: longCmd },
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.commandsExecuted![0].length).toBeLessThanOrEqual(120)
+		expect(summary.commandsExecuted![0].endsWith("...")).toBe(true)
+	})
+
+	it("should deduplicate modified files", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_6",
+							name: "write_to_file",
+							input: { path: "src/index.ts", content: "v1" },
+						},
+					],
+				},
+				{ role: "user", content: [{ type: "tool_result", tool_use_id: "toolu_6", content: "ok" }] },
+				{
+					role: "assistant",
+					content: [
+						{
+							type: "tool_use",
+							id: "toolu_7",
+							name: "apply_diff",
+							input: { path: "src/index.ts", diff: "diff" },
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesModified).toEqual(["src/index.ts"])
+	})
+
+	it("should include tool usage summary from toolUsage", () => {
+		const context = createContext({
+			toolUsage: {
+				write_to_file: { attempts: 3, failures: 0 },
+				read_file: { attempts: 5, failures: 1 },
+			} as any,
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.toolUsageSummary).toEqual({
+			write_to_file: 3,
+			read_file: 5,
+		})
+	})
+
+	it("should include todo stats when todoList is present", () => {
+		const context = createContext({
+			todoList: [
+				{ id: "1", task: "Do A", status: "completed" },
+				{ id: "2", task: "Do B", status: "completed" },
+				{ id: "3", task: "Do C", status: "pending" },
+			] as any,
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.todoStats).toEqual({ completed: 2, total: 3 })
+	})
+
+	it("should skip user messages when scanning for tool_use blocks", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "user",
+					content: [
+						{
+							type: "tool_result" as any,
+							tool_use_id: "toolu_x",
+							content: "ok",
+						},
+					],
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesModified).toBeUndefined()
+		expect(summary.commandsExecuted).toBeUndefined()
+	})
+
+	it("should handle empty conversation history", () => {
+		const context = createContext({ apiConversationHistory: [] })
+		const summary = buildSubtaskSummary(context, "Nothing happened")
+
+		expect(summary.result).toBe("Nothing happened")
+		expect(summary.mode).toBe("code")
+	})
+
+	it("should handle messages with non-array content (string content)", () => {
+		const context = createContext({
+			apiConversationHistory: [
+				{
+					role: "assistant",
+					content: "Just text response",
+				},
+			],
+		})
+
+		const summary = buildSubtaskSummary(context, "Done")
+		expect(summary.filesModified).toBeUndefined()
+	})
+})
+
+describe("formatSubtaskSummaryForApi", () => {
+	it("should format a minimal summary", () => {
+		const text = formatSubtaskSummaryForApi({ result: "All done" })
+		expect(text).toContain("## Result\nAll done")
+	})
+
+	it("should include mode section", () => {
+		const text = formatSubtaskSummaryForApi({ result: "Done", mode: "architect" })
+		expect(text).toContain("## Mode\narchitect")
+	})
+
+	it("should include files modified section", () => {
+		const text = formatSubtaskSummaryForApi({
+			result: "Done",
+			filesModified: ["src/a.ts", "src/b.ts"],
+		})
+		expect(text).toContain("## Files Modified")
+		expect(text).toContain("- src/a.ts")
+		expect(text).toContain("- src/b.ts")
+	})
+
+	it("should include files read section", () => {
+		const text = formatSubtaskSummaryForApi({
+			result: "Done",
+			filesRead: ["package.json"],
+		})
+		expect(text).toContain("## Files Read")
+		expect(text).toContain("- package.json")
+	})
+
+	it("should include commands section", () => {
+		const text = formatSubtaskSummaryForApi({
+			result: "Done",
+			commandsExecuted: ["npm test", "npm build"],
+		})
+		expect(text).toContain("## Commands Executed")
+		expect(text).toContain("- `npm test`")
+		expect(text).toContain("- `npm build`")
+	})
+
+	it("should include todo stats", () => {
+		const text = formatSubtaskSummaryForApi({
+			result: "Done",
+			todoStats: { completed: 3, total: 5 },
+		})
+		expect(text).toContain("## Todos\n3/5 completed")
+	})
+
+	it("should format a comprehensive summary with all sections", () => {
+		const text = formatSubtaskSummaryForApi({
+			result: "Implemented the feature",
+			mode: "code",
+			filesModified: ["src/feature.ts"],
+			filesRead: ["src/config.ts"],
+			commandsExecuted: ["npm test"],
+			todoStats: { completed: 2, total: 2 },
+		})
+
+		expect(text).toContain("## Result")
+		expect(text).toContain("## Mode")
+		expect(text).toContain("## Files Modified")
+		expect(text).toContain("## Files Read")
+		expect(text).toContain("## Commands Executed")
+		expect(text).toContain("## Todos")
+	})
+})