feat(agent-status): child work records say what the child is doing, how it ended, and when

src/relay/agent-status-store-relay-context.test.ts

@@ -7,6 +7,10 @@ import { makeStructuredAgentStatusSubject } from '../shared/agent-status-subject
 const SHARED_CORE_FILES = [
   'agent-status-child-work.ts',
   'agent-status-child-work-codec.ts',
+  'agent-status-child-work-activity-codec.ts',
+  'agent-status-child-work-legality.ts',
+  'agent-status-child-work-value-guards.ts',
+  'agent-status-child-work-view.ts',
   'agent-status-child-work-admission.ts',
   'agent-status-child-work-admission-core.ts',
   'agent-status-child-work-admission-operations.ts',

src/shared/agent-status-child-work-activity-codec.ts

@@ -0,0 +1,101 @@
+import {
+  AGENT_CHILD_WORK_LAST_MESSAGE_MAX_LENGTH,
+  AGENT_CHILD_WORK_OPERATION_BASES,
+  AGENT_CHILD_WORK_RESIDENCIES,
+  type AgentChildWorkInput,
+  type AgentChildWorkOperation,
+  type AgentChildWorkOperationBasis,
+  type AgentChildWorkResidency
+} from './agent-status-child-work'
+import {
+  AGENT_STATUS_TOOL_INPUT_MAX_LENGTH,
+  AGENT_STATUS_TOOL_NAME_MAX_LENGTH
+} from './agent-status-types'
+import {
+  hasOnlyKeys,
+  isBoundedString,
+  isChildWorkText,
+  isRecord,
+  isTimestamp
+} from './agent-status-child-work-value-guards'
+
+const RESIDENCY_SET: ReadonlySet<string> = new Set(AGENT_CHILD_WORK_RESIDENCIES)
+const OPERATION_BASIS_SET: ReadonlySet<string> = new Set(AGENT_CHILD_WORK_OPERATION_BASES)
+
+export type AgentChildWorkActivityFields = Pick<
+  AgentChildWorkInput,
+  'parentChildWorkId' | 'residency' | 'operation' | 'lastMessage'
+>
+
+type AgentChildWorkActivityClock = Pick<
+  AgentChildWorkInput,
+  'childWorkId' | 'firstObservedAt' | 'observedAt'
+>
+
+export function isAgentChildWorkResidency(value: unknown): value is AgentChildWorkResidency {
+  return typeof value === 'string' && RESIDENCY_SET.has(value)
+}
+
+export function isAgentChildWorkOperationBasis(
+  value: unknown
+): value is AgentChildWorkOperationBasis {
+  return typeof value === 'string' && OPERATION_BASIS_SET.has(value)
+}
+
+/** An owner is another child's id; a child never owns itself. */
+export function isAgentChildWorkOwner(value: unknown, childWorkId: string): value is string {
+  return isBoundedString(value) && value !== childWorkId
+}
+
+function parseOperation(
+  value: unknown,
+  clock: AgentChildWorkActivityClock
+): AgentChildWorkOperation | null {
+  if (
+    !isRecord(value) ||
+    !hasOnlyKeys(value, ['toolName', 'basis', 'observedAt'], ['input']) ||
+    !isChildWorkText(value.toolName, AGENT_STATUS_TOOL_NAME_MAX_LENGTH) ||
+    (value.input !== undefined &&
+      !isChildWorkText(value.input, AGENT_STATUS_TOOL_INPUT_MAX_LENGTH)) ||
+    !isAgentChildWorkOperationBasis(value.basis) ||
+    !isTimestamp(value.observedAt) ||
+    // The record's own clock is the newest evidence for this child, so it bounds the operation's.
+    value.observedAt < clock.firstObservedAt ||
+    value.observedAt > clock.observedAt
+  ) {
+    return null
+  }
+  return {
+    toolName: value.toolName,
+    ...(typeof value.input === 'string' ? { input: value.input } : {}),
+    basis: value.basis,
+    observedAt: value.observedAt
+  }
+}
+
+/** Null when any present field is outside what admission can produce. */
+export function parseAgentChildWorkActivityFields(
+  value: Record<string, unknown>,
+  clock: AgentChildWorkActivityClock
+): AgentChildWorkActivityFields | null {
+  const operation =
+    value.operation === undefined ? undefined : parseOperation(value.operation, clock)
+  if (
+    operation === null ||
+    (value.parentChildWorkId !== undefined &&
+      !isAgentChildWorkOwner(value.parentChildWorkId, clock.childWorkId)) ||
+    (value.residency !== undefined && !isAgentChildWorkResidency(value.residency)) ||
+    (value.lastMessage !== undefined &&
+      !isChildWorkText(value.lastMessage, AGENT_CHILD_WORK_LAST_MESSAGE_MAX_LENGTH))
+  ) {
+    return null
+  }
+  return {
+    ...(typeof value.parentChildWorkId === 'string'
+      ? { parentChildWorkId: value.parentChildWorkId }
+      : {}),
+    ...(isAgentChildWorkResidency(value.residency) ? { residency: value.residency } : {}),
+    ...(operation ? { operation } : {}),
+    ...(typeof value.lastMessage === 'string' ? { lastMessage: value.lastMessage } : {})
+  }
+}