feat(#2089): migrate cursor onto imperative adapter + hook-bus/dispatch upgrades

src/host-integration-adapters/imperative-hook-bus.cts

@@ -0,0 +1,153 @@
+/**
+ * Imperative hook-bus adapter — descriptor-driven hooks.json binding
+ * (ADR-1239 Phase D / #2089).
+ *
+ * Generalizes the Cursor-specific `writeCursorHooksJson`/`removeCursorHooksJson`
+ * into a descriptor-driven hook-bus binding that reads the negotiated `hookBus`
+ * axis + the host's documented hook-event list (from
+ * `runtime.hostBehaviors.managedHookEvents`), NOT a hardcoded
+ * `sessionStart`/`postToolUse` pair.
+ *
+ * This module is PURE (no I/O): it resolves the event→script mapping and builds
+ * the hooks.json entry manifest. The actual file I/O (copying scripts, writing
+ * hooks.json) stays in `runtime-hooks-surface.cts`, which calls into the pure
+ * functions exported here. This separation makes the binding testable without a
+ * filesystem.
+ *
+ * Cursor hook-event universe (closed vocabulary per ADR-1239,
+ * https://cursor.com/docs/hooks):
+ *   sessionStart, sessionEnd, preToolUse, postToolUse, subagentStart,
+ *   subagentStop, beforeShellExecution, afterShellExecution,
+ *   afterMCPExecution, afterFileEdit, preCompact, stop,
+ *   beforeTabFileRead, afterTabFileEdit, workspaceOpen
+ *
+ * GSD registers for the 6 events in the portable floor + subagent lifecycle
+ * (AC4a upgrade, #2089):
+ *   sessionStart, postToolUse, preToolUse, stop, subagentStart, subagentStop
+ */
+'use strict';
+
+/**
+ * The full set of Cursor hook events GSD can register for.
+ * Frozen closed vocabulary — adding an event requires updating both this set
+ * and the event→script mapping below.
+ */
+export const CURSOR_HOOK_EVENTS = Object.freeze([
+  'sessionStart',
+  'postToolUse',
+  'preToolUse',
+  'stop',
+  'subagentStart',
+  'subagentStop',
+] as const);
+
+export type CursorHookEvent = (typeof CURSOR_HOOK_EVENTS)[number];
+
+/**
+ * Event → hook-script mapping. Each event maps to a standalone `.js` script
+ * under `hooks/` that Cursor invokes via `hooks.json`.
+ *
+ * Convention: `gsd-cursor-<kebab-event>.js`. The script files are authored in
+ * `hooks/` and copied to `<configDir>/hooks/` during install by
+ * `runtime-hooks-surface.cts`.
+ */
+export const CURSOR_EVENT_SCRIPT_MAP: Readonly<Record<string, string>> = Object.freeze({
+  sessionStart: 'gsd-cursor-session-start.js',
+  postToolUse: 'gsd-cursor-post-tool.js',
+  preToolUse: 'gsd-cursor-pre-tool.js',
+  stop: 'gsd-cursor-stop.js',
+  subagentStart: 'gsd-cursor-subagent-start.js',
+  subagentStop: 'gsd-cursor-subagent-stop.js',
+});
+
+/**
+ * The GSD-managed marker written into each hooks.json entry so the
+ * reconcile pass can distinguish GSD-owned entries from user-owned ones.
+ */
+export const GSD_HOOK_MARKER = 'gsd-managed';
+
+/**
+ * Resolve the managed hook events from a runtime descriptor's
+ * `hostBehaviors.managedHookEvents` list. Falls back to the full
+ * `CURSOR_HOOK_EVENTS` set when the descriptor does not declare the list
+ * (backward-compat for descriptors predating #2089).
+ *
+ * Pure: no I/O, never throws. Unknown event names are silently filtered
+ * (fail-closed — an unrecognized event is never registered).
+ *
+ * @param managedHookEvents - the descriptor's `hostBehaviors.managedHookEvents` array
+ * @returns a deduplicated, validated array of event names
+ */
+export function resolveManagedHookEvents(
+  managedHookEvents: readonly string[] | null | undefined,
+): readonly string[] {
+  if (!Array.isArray(managedHookEvents) || managedHookEvents.length === 0) {
+    return CURSOR_HOOK_EVENTS;
+  }
+  const valid = new Set<string>(CURSOR_HOOK_EVENTS);
+  const seen = new Set<string>();
+  const result: string[] = [];
+  for (const ev of managedHookEvents) {
+    if (typeof ev === 'string' && valid.has(ev) && !seen.has(ev)) {
+      seen.add(ev);
+      result.push(ev);
+    }
+  }
+  return result.length > 0 ? result : CURSOR_HOOK_EVENTS;
+}
+
+/**
+ * Build the list of hook script files that need to be copied for the given
+ * managed events. Each event maps to a script via `CURSOR_EVENT_SCRIPT_MAP`.
+ *
+ * Pure: returns a deduplicated array of script filenames.
+ *
+ * @param events - the managed event names (validated by `resolveManagedHookEvents`)
+ * @returns array of script filenames (e.g. `['gsd-cursor-session-start.js', ...]`)
+ */
+export function resolveHookScripts(
+  events: readonly string[],
+): readonly string[] {
+  const scripts: string[] = [];
+  const seen = new Set<string>();
+  for (const ev of events) {
+    const script = CURSOR_EVENT_SCRIPT_MAP[ev];
+    if (script && !seen.has(script)) {
+      seen.add(script);
+      scripts.push(script);
+    }
+  }
+  return scripts;
+}
+
+/**
+ * Build the hooks.json managed-entry manifest for the given events.
+ * Each entry is `{ type: 'command', command: <cmd>, [GSD_HOOK_MARKER]: true }`.
+ *
+ * The `command` string is built by the caller (it requires platform-specific
+ * node-runner resolution from `runtime-hooks-surface.cts`). This function
+ * receives a pre-built `event → command` map and attaches the marker.
+ *
+ * Pure: no I/O.
+ *
+ * @param events - the managed event names
+ * @param commands - a map of event → command string (built by the caller)
+ * @returns a map of event → managed entry, ready for hooks.json reconciliation
+ */
+export function buildHookBusEntries(
+  events: readonly string[],
+  commands: Readonly<Record<string, string | null>>,
+): Record<string, { type: string; command: string; [key: string]: unknown }> {
+  const entries: Record<string, { type: string; command: string; [key: string]: unknown }> = {};
+  for (const ev of events) {
+    const cmd = commands[ev];
+    if (cmd) {
+      entries[ev] = {
+        type: 'command',
+        command: cmd,
+        [GSD_HOOK_MARKER]: true,
+      };
+    }
+  }
+  return entries;
+}