Files
everything-claude-code/tests/hooks/ecc-metrics-bridge.test.js
Jamkris 4f21ed2acf fix(hooks): use last cumulative row for session cost in metrics bridge
`ecc-metrics-bridge.js#readSessionCost` summed the
`estimated_cost_usd`, `input_tokens`, and `output_tokens` of
every matching row in `~/.claude/metrics/costs.jsonl`. That breaks
the documented contract of `scripts/hooks/cost-tracker.js`, which
explicitly states (in its module docblock):

  Cumulative behavior: Stop fires per assistant response, not
  per session. Each row therefore represents the cumulative
  session total up to that point. To get per-session cost, take
  the last row per session_id.

Summing N cumulative rows over-counts by roughly (N+1)/2 ×. For a
session with 3 rows at 0.01, 0.02, 0.03 USD (true running total
0.03), the bridge today reports 0.06 USD. The over-counted value
feeds `ecc-context-monitor.js`, which then trips its
COST_NOTICE_USD / COST_WARNING_USD / COST_CRITICAL_USD thresholds
on phantom spend AND injects the inflated number as
`additionalContext` into the live model turn — so the agent
itself is told a wrong cost.

Reproduced on `main` before this commit:

  $ cat > /tmp/eccc/.claude/metrics/costs.jsonl <<EOF
  {"session_id":"S1","estimated_cost_usd":0.01,"input_tokens":333,"output_tokens":166}
  {"session_id":"S1","estimated_cost_usd":0.02,"input_tokens":666,"output_tokens":333}
  {"session_id":"S1","estimated_cost_usd":0.03,"input_tokens":1000,"output_tokens":500}
  EOF

  $ HOME=/tmp/eccc node -e 'const m = require("./scripts/hooks/ecc-metrics-bridge.js"); \
      console.log(JSON.stringify(m.readSessionCost("S1")))'
  {"totalCost":0.06,"totalIn":1999,"totalOut":999}

Expected: `{"totalCost":0.03,"totalIn":1000,"totalOut":500}` (the
last cumulative row).
Actual: 2× over-count.

Fix: replace `+=` with `=` in the matching branch so the assigned
values reflect the most recent row encountered. The iteration
order is file order, which is also event time order, so the last
assignment wins — exactly the contract cost-tracker writes
against.

After this commit the reproduction above returns
`{"totalCost":0.03,"totalIn":1000,"totalOut":500}`.

Regression test in `tests/hooks/ecc-metrics-bridge.test.js`:
`readSessionCost returns the LAST cumulative row, not the sum
(cost-tracker contract)`. The existing
`readSessionCost does not include unrelated default-session rows`
test happened to pass even with the bug because it only had one
target-session row — single-row sessions are coincidentally
correct under both formulas. The new test uses three rows so the
two formulas diverge.

A second issue in the same function — the 8 KiB tail-only read
silently drops older rows once a session's recent cumulative
totals scroll past that window — is fixed in the next commit.
2026-05-17 21:41:24 -04:00

259 lines
8.0 KiB
JavaScript

/**
* Tests for scripts/hooks/ecc-metrics-bridge.js
*
* Run with: node tests/hooks/ecc-metrics-bridge.test.js
*/
const assert = require('assert');
const fs = require('fs');
const os = require('os');
const path = require('path');
const { run, hashToolCall, extractFilePaths, readSessionCost } = require('../../scripts/hooks/ecc-metrics-bridge');
// Test helper
function test(name, fn) {
try {
fn();
console.log(` \u2713 ${name}`);
return true;
} catch (err) {
console.log(` \u2717 ${name}`);
console.log(` Error: ${err.message}`);
return false;
}
}
function makeTempHome() {
return fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-metrics-bridge-test-'));
}
function runTests() {
console.log('\n=== Testing ecc-metrics-bridge.js ===\n');
let passed = 0;
let failed = 0;
// hashToolCall tests
console.log('hashToolCall:');
if (
test('returns 8-char hex string', () => {
const hash = hashToolCall('Bash', { command: 'ls' });
assert.strictEqual(hash.length, 8);
assert.ok(/^[0-9a-f]{8}$/.test(hash), `Expected hex, got: ${hash}`);
})
)
passed++;
else failed++;
if (
test('different Bash commands produce different hashes', () => {
const h1 = hashToolCall('Bash', { command: 'ls' });
const h2 = hashToolCall('Bash', { command: 'pwd' });
assert.notStrictEqual(h1, h2);
})
)
passed++;
else failed++;
if (
test('different Edit file_paths produce different hashes', () => {
const h1 = hashToolCall('Edit', { file_path: 'a.js' });
const h2 = hashToolCall('Edit', { file_path: 'b.js' });
assert.notStrictEqual(h1, h2);
})
)
passed++;
else failed++;
if (
test('same inputs produce same hash (deterministic)', () => {
const h1 = hashToolCall('Write', { file_path: 'x.txt' });
const h2 = hashToolCall('Write', { file_path: 'x.txt' });
assert.strictEqual(h1, h2);
})
)
passed++;
else failed++;
if (
test('non-file tools hash by stable input to avoid false loop collisions', () => {
const h1 = hashToolCall('Glob', { pattern: '**/*.js', path: '/repo/a' });
const h2 = hashToolCall('Glob', { pattern: '**/*.md', path: '/repo/a' });
const h3 = hashToolCall('Glob', { path: '/repo/a', pattern: '**/*.js' });
assert.notStrictEqual(h1, h2);
assert.strictEqual(h1, h3);
})
)
passed++;
else failed++;
// extractFilePaths tests
console.log('\nextractFilePaths:');
if (
test('Edit with file_path returns [file_path]', () => {
const paths = extractFilePaths('Edit', { file_path: 'a.js' });
assert.deepStrictEqual(paths, ['a.js']);
})
)
passed++;
else failed++;
if (
test('MultiEdit with edits array returns all file_paths', () => {
const paths = extractFilePaths('MultiEdit', {
edits: [{ file_path: 'a.js' }, { file_path: 'b.js' }]
});
assert.deepStrictEqual(paths, ['a.js', 'b.js']);
})
)
passed++;
else failed++;
if (
test('Bash with command returns empty array', () => {
const paths = extractFilePaths('Bash', { command: 'ls' });
assert.deepStrictEqual(paths, []);
})
)
passed++;
else failed++;
if (
test('null toolInput returns empty array', () => {
const paths = extractFilePaths('Edit', null);
assert.deepStrictEqual(paths, []);
})
)
passed++;
else failed++;
// readSessionCost tests
console.log('\nreadSessionCost:');
if (
test('nonexistent session returns object with numeric fields', () => {
const result = readSessionCost('nonexistent-session-cost-test-xyz-999');
assert.strictEqual(typeof result.totalCost, 'number');
assert.strictEqual(typeof result.totalIn, 'number');
assert.strictEqual(typeof result.totalOut, 'number');
assert.ok(result.totalCost >= 0, 'totalCost should be non-negative');
})
)
passed++;
else failed++;
if (
test('readSessionCost returns the LAST cumulative row, not the sum (cost-tracker contract)', () => {
// cost-tracker.js writes one row per Stop event; each row is already
// a cumulative session total ("To get per-session cost, take the
// last row per session_id."). Summing across rows over-counts:
// 0.01 + 0.02 + 0.03 = 0.06, but the correct answer is 0.03.
const tmpHome = makeTempHome();
const originalHome = process.env.HOME;
const originalUserProfile = process.env.USERPROFILE;
try {
process.env.HOME = tmpHome;
process.env.USERPROFILE = tmpHome;
const metricsDir = path.join(tmpHome, '.claude', 'metrics');
fs.mkdirSync(metricsDir, { recursive: true });
fs.writeFileSync(
path.join(metricsDir, 'costs.jsonl'),
[
JSON.stringify({ session_id: 'S1', estimated_cost_usd: 0.01, input_tokens: 333, output_tokens: 166 }),
JSON.stringify({ session_id: 'S1', estimated_cost_usd: 0.02, input_tokens: 666, output_tokens: 333 }),
JSON.stringify({ session_id: 'S1', estimated_cost_usd: 0.03, input_tokens: 1000, output_tokens: 500 })
].join('\n') + '\n',
'utf8'
);
const result = readSessionCost('S1');
assert.strictEqual(result.totalCost, 0.03, `expected last-row 0.03, got ${result.totalCost} (was the bug: 0.06)`);
assert.strictEqual(result.totalIn, 1000);
assert.strictEqual(result.totalOut, 500);
} finally {
if (originalHome === undefined) delete process.env.HOME;
else process.env.HOME = originalHome;
if (originalUserProfile === undefined) delete process.env.USERPROFILE;
else process.env.USERPROFILE = originalUserProfile;
fs.rmSync(tmpHome, { recursive: true, force: true });
}
})
)
passed++;
else failed++;
if (
test('readSessionCost does not include unrelated default-session rows', () => {
const tmpHome = makeTempHome();
const originalHome = process.env.HOME;
const originalUserProfile = process.env.USERPROFILE;
try {
process.env.HOME = tmpHome;
process.env.USERPROFILE = tmpHome;
const metricsDir = path.join(tmpHome, '.claude', 'metrics');
fs.mkdirSync(metricsDir, { recursive: true });
fs.writeFileSync(
path.join(metricsDir, 'costs.jsonl'),
[
JSON.stringify({ session_id: 'default', estimated_cost_usd: 50, input_tokens: 1000, output_tokens: 2000 }),
JSON.stringify({ session_id: 'target-session', estimated_cost_usd: 1.25, input_tokens: 10, output_tokens: 20 })
].join('\n') + '\n',
'utf8'
);
const result = readSessionCost('target-session');
assert.strictEqual(result.totalCost, 1.25);
assert.strictEqual(result.totalIn, 10);
assert.strictEqual(result.totalOut, 20);
} finally {
if (originalHome === undefined) delete process.env.HOME;
else process.env.HOME = originalHome;
if (originalUserProfile === undefined) delete process.env.USERPROFILE;
else process.env.USERPROFILE = originalUserProfile;
fs.rmSync(tmpHome, { recursive: true, force: true });
}
})
)
passed++;
else failed++;
// run tests
console.log('\nrun:');
if (
test('empty input returns empty input without crashing', () => {
const result = run('');
assert.strictEqual(result, '');
})
)
passed++;
else failed++;
if (
test('whitespace-only input returns input unchanged', () => {
const result = run(' ');
assert.strictEqual(result, ' ');
})
)
passed++;
else failed++;
if (
test('input without session_id returns input unchanged', () => {
const input = JSON.stringify({ tool_name: 'Bash', tool_input: { command: 'ls' } });
const result = run(input);
assert.strictEqual(result, input);
})
)
passed++;
else failed++;
// Summary
console.log(`\nResults: ${passed} passed, ${failed} failed\n`);
return { passed, failed };
}
const { failed } = runTests();
process.exit(failed > 0 ? 1 : 0);