feat(hooks): enforce research loop cap at PreToolUse or document the gap

This commit is contained in:
Kjell Tore Guttormsen 2026-08-12 20:21:42 +02:00
commit e9ff8ab023
6 changed files with 441 additions and 2 deletions

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// tests/hooks/agent-cap.test.mjs
// Step 10 — pins hooks/scripts/pre-agent-cap.mjs, the PreToolUse enforcement
// of the /trekresearch Phase 5 loop bound.
//
// The spike (docs/spike-pretooluse-subagent-reach.md, RESULT: FIRES) proved a
// plugin PreToolUse hook observes sub-agent tool calls, so the cap can be
// enforced rather than merely documented. This file pins the two properties
// that matter in opposite directions:
//
// (a) it DENIES (exit 2) once the ledger shows the budget spent, and
// (b) it does NOT over-block — an unrelated session, unparsable stdin, a
// stale marker, or the kill switch all exit 0.
//
// Pattern: tests/hooks/bash-guard.test.mjs (child process via runHook).
import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { mkdtempSync, mkdirSync, writeFileSync, readFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { runHookWithEnv } from '../helpers/hook-helper.mjs';
const HERE = dirname(fileURLToPath(import.meta.url));
const ROOT = join(HERE, '..', '..');
const CAP_HOOK = join(ROOT, 'hooks', 'scripts', 'pre-agent-cap.mjs');
const HOOKS_JSON = join(ROOT, 'hooks', 'hooks.json');
const SESSION = 'sess-abc123';
const RUN_ID = 'run-xyz789';
/**
* Build a throwaway CLAUDE_PLUGIN_DATA dir holding a scope marker for
* `sessionId` and `turns` ledger entries for RUN_ID.
*/
function fixture({ turns = 0, sessionId = SESSION, startedAt = new Date() } = {}) {
const dir = mkdtempSync(join(tmpdir(), 'voyage-cap-'));
mkdirSync(join(dir, 'trekresearch-loop-scope'), { recursive: true });
writeFileSync(
join(dir, 'trekresearch-loop-scope', `${sessionId}.json`),
JSON.stringify({ runId: RUN_ID, startedAt: startedAt.toISOString() }),
);
const ledger = Array.from({ length: turns }, (_, i) =>
JSON.stringify({ ts: new Date().toISOString(), runId: RUN_ID, dimension: `d${i}`, effort: 'high' }),
).join('\n');
writeFileSync(join(dir, 'trekresearch-loop-ledger.jsonl'), ledger ? ledger + '\n' : '');
return dir;
}
// TREKRESEARCH_MAX_CONV_TURNS=1 => budget = 1 * MAX_TOTAL_DIMENSIONS (8).
const CAPPED_ENV = { VOYAGE_STORM_ENABLED: '1', TREKRESEARCH_MAX_CONV_TURNS: '1' };
const BUDGET = 8;
function searchInput(sessionId = SESSION) {
return {
session_id: sessionId,
hook_event_name: 'PreToolUse',
tool_name: 'WebSearch',
tool_input: { query: 'claude code hooks reference' },
agent_id: 'aa6d19525a4680fe0',
agent_type: 'general-purpose',
};
}
// -----------------------------------------------------------------------
// DENY — budget spent
// -----------------------------------------------------------------------
test('pre-agent-cap DENIES a loop turn once the ledger shows the budget spent', async () => {
const dir = fixture({ turns: BUDGET });
const { code, stderr } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 2);
assert.match(stderr, /loop cap/i, 'stderr must name the cap it enforced');
assert.match(stderr, new RegExp(`${BUDGET}`), 'stderr must state the budget');
});
test('pre-agent-cap DENIES above the budget too (used > budget)', async () => {
const dir = fixture({ turns: BUDGET + 5 });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 2);
});
// -----------------------------------------------------------------------
// ALLOW — under the cap
// -----------------------------------------------------------------------
test('pre-agent-cap ALLOWS a loop turn under the budget', async () => {
const dir = fixture({ turns: BUDGET - 1 });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0);
});
// -----------------------------------------------------------------------
// DOES NOT OVER-BLOCK — the property that keeps this hook safe to wire
// globally. A broken PreToolUse hook would brick every session on the box.
// -----------------------------------------------------------------------
test('pre-agent-cap ALLOWS an unrelated session even when a loop is exhausted', async () => {
const dir = fixture({ turns: BUDGET });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput('some-other-session'), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0, 'no scope marker for this session_id => out of scope');
});
test('pre-agent-cap ALLOWS when no scope marker directory exists at all', async () => {
const dir = mkdtempSync(join(tmpdir(), 'voyage-cap-empty-'));
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0);
});
test('pre-agent-cap ALLOWS on unparsable stdin', async () => {
const dir = fixture({ turns: BUDGET });
const { code } = await runHookWithEnv(CAP_HOOK, 'not json at all', {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0);
});
test('pre-agent-cap ALLOWS when the input carries no session_id', async () => {
const dir = fixture({ turns: BUDGET });
const input = searchInput();
delete input.session_id;
const { code } = await runHookWithEnv(CAP_HOOK, input, {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0);
});
// -----------------------------------------------------------------------
// TTL / auto-reset — a marker left behind by a crashed run must not deny
// tool calls forever.
// -----------------------------------------------------------------------
test('pre-agent-cap ALLOWS when the scope marker is older than the TTL', async () => {
const dir = fixture({ turns: BUDGET, startedAt: new Date(Date.now() - 48 * 3600 * 1000) });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
VOYAGE_CAP_SCOPE_TTL_MS: '1000',
});
assert.strictEqual(code, 0, 'a stale marker must auto-reset, not deny forever');
});
// -----------------------------------------------------------------------
// Kill switch + default-off
// -----------------------------------------------------------------------
test('pre-agent-cap kill switch VOYAGE_DISABLE_CAP_HOOK=1 allows an exhausted loop', async () => {
const dir = fixture({ turns: BUDGET });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: dir,
VOYAGE_DISABLE_CAP_HOOK: '1',
});
assert.strictEqual(code, 0);
});
test('pre-agent-cap is inert when VOYAGE_STORM_ENABLED is not 1 (default-off)', async () => {
const dir = fixture({ turns: BUDGET });
const { code } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
VOYAGE_STORM_ENABLED: '0',
CLAUDE_PLUGIN_DATA: dir,
});
assert.strictEqual(code, 0);
});
// -----------------------------------------------------------------------
// Fail-closed inside scope — in scope but the ledger is unreachable means
// the hook cannot count, and a cap that cannot count must not grant.
// -----------------------------------------------------------------------
test('pre-agent-cap DENIES in scope when CLAUDE_PLUGIN_DATA is absent', async () => {
const dir = fixture({ turns: 0 });
const { code, stderr } = await runHookWithEnv(CAP_HOOK, searchInput(), {
...CAPPED_ENV,
CLAUDE_PLUGIN_DATA: '',
VOYAGE_CAP_SCOPE_DIR: dir,
});
assert.strictEqual(code, 2);
assert.match(stderr, /CLAUDE_PLUGIN_DATA/, 'stderr must name the missing variable');
});
// -----------------------------------------------------------------------
// Append-only counting — the hook reads the ledger, it never writes it.
// Writing per tool call would make the cap count its own enforcement.
// -----------------------------------------------------------------------
test('pre-agent-cap never writes to the ledger', async () => {
const dir = fixture({ turns: 2 });
const ledgerPath = join(dir, 'trekresearch-loop-ledger.jsonl');
const before = readFileSync(ledgerPath, 'utf-8');
await runHookWithEnv(CAP_HOOK, searchInput(), { ...CAPPED_ENV, CLAUDE_PLUGIN_DATA: dir });
assert.strictEqual(readFileSync(ledgerPath, 'utf-8'), before);
});
// -----------------------------------------------------------------------
// Wiring — pattern from tests/hooks/hooks-json-stop-wired.test.mjs
// -----------------------------------------------------------------------
function invocationOf(h) {
return [h.command || '', ...(h.args || [])].join(' ').trim();
}
test('hooks.json wires pre-agent-cap.mjs on PreToolUse with ${CLAUDE_PLUGIN_ROOT}', () => {
const cfg = JSON.parse(readFileSync(HOOKS_JSON, 'utf8'));
const invocations = (cfg.hooks.PreToolUse || []).flatMap((entry) =>
(entry.hooks || []).map(invocationOf),
);
const capInvocation = invocations.find((cmd) => cmd.includes('pre-agent-cap.mjs'));
assert.ok(capInvocation, `no PreToolUse hook references pre-agent-cap.mjs. Found: ${JSON.stringify(invocations)}`);
assert.match(capInvocation, /\$\{CLAUDE_PLUGIN_ROOT\}/, 'relative paths fail in headless sessions');
assert.match(capInvocation, /^node\s+/);
});
test('hooks.json matcher for pre-agent-cap covers the loops outbound surface', () => {
const cfg = JSON.parse(readFileSync(HOOKS_JSON, 'utf8'));
const entry = (cfg.hooks.PreToolUse || []).find((e) =>
(e.hooks || []).some((h) => invocationOf(h).includes('pre-agent-cap.mjs')),
);
assert.ok(entry, 'pre-agent-cap entry missing from PreToolUse');
for (const tool of ['WebSearch', 'WebFetch', 'Task']) {
assert.match(entry.matcher, new RegExp(tool), `matcher must cover ${tool}`);
}
});