I3121 — The release compatibility analyzer's invariants hold under property tests

○READY wave 0 · p2 · implementation profile · parallel safe

Part of a-test-fails-when-the-code-is-wrong — The suites that guard critical predicates are shown to fail when those predicates are wrong.

Objective

Add proptest properties to apps/majordomus-cli/src/release/compat.rs: diff(a,a) is empty; reordering a surface gives no change; adding a distinct atom is at least minor; removing one is at least major from 1.0; normalisation is idempotent.

Why

Proposed on 2026-09-11 (c111#6) when the owner ordered that Elm-like versioning be enforced. The version a landing allocates (ADR 0134) rests on this analyzer, and on master 707a04c (grep -c '#\\[test\\]' apps/majordomus-cli/src/release/compat.rs, 2026-10-18) it has 33 example tests and no property. Sources: chatgpt-majordomus:c111#6, chatgpt-majordomus:c079#6.

Current state

compat.rs: 33 #[test]s on master 707a04c (same grep). proptest is a dev-dependency used in other modules (mesh, deploy, served, integration, economics). surface.rs:699 tests normalisation idempotence on one example.

Desired state

Five named properties in the lib suite.

Scope

• apps/majordomus-cli/src/release/compat.rs

Out of scope

• Changing the bump policy

Dependencies

None. This issue is a root of the graph.

Acceptance criteria

• Each of the five properties runs at the default case count and passes

Validation

• cargo test --manifest-path apps/majordomus-cli/Cargo.toml --lib release::compat

Evidence required

• compat_properties

Evidence

None recorded. Every token above needs a command or an artifact behind it before this issue can be completed; narrative is refused.

Timeline

started

—

verified

—

completed

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Those three fields, the evidence above and the state of the dependencies are all the status is made of. There is no status field to disagree with them.

Canonical record: .ai/repo/project/issues/I3121.yaml. Read it back with majordomus plan show I3121.