# Count and quantity

**Test family:** `CNT`

- **CNT-001** Zero has the intended empty/unavailable/free meaning; negative is rejected unless domain-valid.
- **CNT-002** Singular/plural and compact formatting do not change the numeric value.
- **CNT-003** Count equals independently enumerated items across filters, pagination, archived data, and permissions.
- **CNT-004** Increment/decrement at stock/seat/quota limit is atomic under concurrency.
- **CNT-005** Derived counts update after create/delete/archive/restore and eventually consistent delay is visible.
- **CNT-006** Huge count caps display deliberately without corrupting sort, comparisons, or export.

## Comprehensive per-item coverage

- **CNT-007** Exercise absent, null, empty, zero, false, ordinary, minimum, maximum, below-minimum, above-maximum, and unknown values distinctly.
- **CNT-008** Probe powers-of-two and representation boundaries around `7/8/9`, `15/16/17`, `31/32/33`, `63/64/65`, and storage-specific limits.
- **CNT-009** Use negative, fractional, high-precision, exponential, signed-zero, NaN/infinity, overflow, underflow, and rounding cases where the type can receive them.
- **CNT-010** Use labels or serialized values containing emoticons, emoji, kaomoji, accents, RTL, combining marks, confusables, and invisible characters.
- **CNT-011** Compare UI, API, import, database, cache, queue, analytics, search index, notification, and export representations; preserve one authoritative meaning.
- **CNT-012** Send wrong types, missing fields, extra fields, duplicate keys, unknown enum members, malformed encodings, and schema-version mismatches.
- **CNT-013** Bypass client min/max/step/format constraints; enforce the server and persistence contract without clipping or coercing silently.
- **CNT-014** Switch locale, numbering system, decimal/group separator, calendar, currency, time zone, and direction; separate display formatting from stored value.
- **CNT-015** Sort, filter, group, aggregate, compare, search, paginate, and chart boundary and null values; keep ordering and totals coherent.
- **CNT-016** Create and update concurrently from two sessions; prevent lost updates, duplicate identities, and stale derived values.
- **CNT-017** Retry writes and reads across timeout, disconnect, failover, and replica lag; expose stale or uncertain state rather than false certainty.
- **CNT-018** Migrate old, missing, malformed, and newly extended values forward and backward where supported; preserve auditability and rollback.
- **CNT-019** Verify permissions at field, record, tenant, export, analytics, log, cache, and backup layers; redact consistently.
- **CNT-020** Use inert markup, SQL, template, CSV-formula, path, and log canaries in any textual representation; encode for each output context.
- **CNT-021** Check accessible names, units, errors, table headers, announcements, and non-color distinctions for input and display.
- **CNT-022** Measure validation, calculation, query, sort, aggregate, import, and export behavior at normal and supported scale.
- **CNT-023** Verify derived totals, counters, scores, dates, and statuses update atomically with source data or expose reconciliation state.
- **CNT-024** Delete, restore, archive, expire, retain, and purge values; distinguish tombstone, null, zero, redaction, and absence.
- **CNT-025** Record source, actor, old/new value, unit, time, version, and reason without leaking secrets or prohibited personal data.
- **CNT-026** Reconcile after partial failure, cache corruption, duplicate message, and delayed index update; detect and repair divergence.

[Back to Numbers, money, dates, and time index](../../numbers-money-time.md)
