ProofDiff · evidence report

What evidence exists for this change?

A local, evidence-based view of changed code, related tests, deterministic checks, and the places that still need human judgment.

billing-serviceworking tree vs HEAD2026-08-12T00:00:00.000Z927ff84f0aad

Verification failed

1 changed files · 1 changed symbols · highest risk critical

An applicable verification command failed, errored, or timed out.

Change review queue

Highest-risk files appear first. Expand a file to audit each claim.

src/tax.js

modified · +1 −1 · javascript

Verification failedcritical risk · 80

function · taxFor

An applicable verification command failed, errored, or timed out.

Inspect evidence and reasoning

Evidence

targeted node-test: 1 qualified test target: test/tax.test.js
ProofDiff explicitly supplied this runner-qualified target. The runner observed 0 passed, 1 failed, and 0 skipped test for this exact target.
high confidence · failing check
1 statically related test-like path
Related by resolved local import/dependency paths or accepted runner qualification. Static relationship and runner identity are not runtime coverage.
medium confidence · related test
1 call reference in changed lines
Parser-observed name-only call sites: Number. Targets are not resolved and runtime execution is not implied.
high confidence · static relationship
1 impacted file
Reachable through resolved reverse import relationships. This is an impact estimate, not proof of runtime behavior.
medium confidence · static relationship
@babel/parser structural analysis
Parser confidence: high. Structural findings are evidence about code shape, not correctness.
high confidence · inference
Evidence boundary · runtime-observation · target-failed
A runner-qualified related target was explicitly supplied and observed failing. Next action: Inspect the attributed target failure before seeking stronger positive evidence.
high confidence · limitation

Why review this

An applicable verification check failed.

Targeted test outcomes 1

failed test/tax.test.js

Statically related test-like paths 1

test/tax.test.js

Calls in changed lines 1

Number line 2 · high confidence

Name-only structural references; targets are not resolved and runtime execution is not implied.

Estimated impact 1

test/tax.test.js

Limits

Statically related test-like paths were found, but no runner-qualified exact target produced a non-skipped passing test observation.

Verification checks

Commands, outcomes, and bounded output from this run.

failedtest: test150 ms

The command exited with code 1. package.json script "test".

npm run test --silent

✖ applies the configured twenty-percent tax (0.570542ms)
ℹ tests 1
ℹ suites 0
ℹ pass 0
ℹ fail 1
ℹ cancelled 0
ℹ skipped 0
ℹ todo 0
ℹ duration_ms 40.921667

✖ failing tests:

test at test/tax.test.js:5:1
✖ applies the configured twenty-percent tax (0.570542ms)
  AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

  2 !== 20

      at TestContext.<anonymous> ([REPOSITORY]/test/tax.test.js:6:10)
      at Test.runInAsyncScope (node:async_hooks:227:14)
      at Test.run (node:internal/test_runner/test:1201:25)
      at Test.start (node:internal/test_runner/test:1096:17)
      at startSubtestAfterBootstrap (node:internal/test_runner/harness:385:17) {
    generatedMessage: true,
    code: 'ERR_ASSERTION',
    actual: 2,
    expected: 20,
    operator: 'strictEqual',
    diff: 'simple'
  }

failedtargeted node-test: 1 qualified test target76 ms

The command exited with code 1. Target observations: 0 passed, 1 failed, 0 skipped, 0 zero-test, 0 unavailable. ProofDiff targeted execution derived from package.json script "test".

node --test --test-reporter=<ProofDiff observer> test/tax.test.js

Target qualifications

test/tax.test.js → test/tax.test.js · runner-default-pattern (high)
test/tax.test.js matches a documented default node --test discovery pattern. Default-pattern qualification establishes runner identity, not test execution or behavioral coverage.

Target observations

failed test/tax.test.js · 1 non-skipped observed
The runner observed 0 passed, 1 failed, and 0 skipped test for this exact target.

✖ applies the configured twenty-percent tax (0.573667ms)
ℹ tests 1
ℹ suites 0
ℹ pass 0
ℹ fail 1
ℹ cancelled 0
ℹ skipped 0
ℹ todo 0
ℹ duration_ms 42.916833

✖ failing tests:

test at test/tax.test.js:5:1
✖ applies the configured twenty-percent tax (0.573667ms)
  AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

  2 !== 20

      at TestContext.<anonymous> ([REPOSITORY]/test/tax.test.js:6:10)
      at Test.runInAsyncScope (node:async_hooks:227:14)
      at Test.run (node:internal/test_runner/test:1201:25)
      at Test.start (node:internal/test_runner/test:1096:17)
      at startSubtestAfterBootstrap (node:internal/test_runner/harness:385:17) {
    generatedMessage: true,
    code: 'ERR_ASSERTION',
    actual: 2,
    expected: 20,
    operator: 'strictEqual',
    diff: 'simple'
  }

How to read this: The JSON status verified is displayed as “Related test file passed.” It requires a static relationship, runner qualification, explicit target supply, and at least one non-skipped passing test observed for that exact path—not changed-symbol or changed-line execution, mathematical proof, or a guarantee of safety.