Equality and hashing disagree

Rule ID: correctness.equality-hash-contract@1.0.0. Availability below refers to source-scan at product 524fa07e.

V-COR-01 — Equality and hashing disagree#

Equality and hashing disagree. It examines value, collection, identity, ordering, and control-flow contracts.

Availability#

Not available in source-scan. There is no source-scan flag to activate this condition.

Example and action#

Illustrative design scenario, not a runnable Swift example or a reproduced analyzer result. The stated availability and evidence boundaries still apply.

Before: Two records compare equal by ID, but their hash also includes a mutable display name.

Review the following change against the contract and build variants described above.

After: Use the same stable identity fields for equality and hashing. Check equal values with different display names and avoid mutating identity while a value is a set member or dictionary key.

Intended analysis#

Intended reasoning: Compare the value, unit, identity or protocol assumptions at each operation. The intended conclusion requires consistent source identities and the relevant path constraints; an unrecognized abstraction can invalidate the comparison. Required evidence: value, identity, ordering, collection, and control-flow facts

Assumptions and unknown#

The relevant facts must be admitted for the selected immutable build world. Unknown aliases, external effects, unsupported source forms or incomplete consumers can prevent a conclusion. Availability in this workflow is stated above; the illustration does not expand that availability.

Evidence and interpretation#

The target catalog describes the intended condition. It is not evidence of an active source-scan diagnostic.

Historical evidence at 4558458d: accepted-subset (a limited set of source forms and profiles passed historical checks). That evidence has not been requalified for this product revision.

How we validate checks explains the evidence boundary. Foundations separates method assumptions from implementation claims.