jackin-test-support

Canonical fakes and role-repo seed helpers shared across jackin❯ workspace test suites — extracted so that jackin-isolation no longer had to dev-depend back up on jackin-runtime just to reach FakeRunner/FakeDockerClient (the workspace's only prod+dev dependency cycle).

What this crate owns

FakeRunner — an in-memory jackin_core::CommandRunner fake for subprocess injection.
FakeDockerClient — an in-memory jackin_core::DockerApi fake.
seed_valid_role_repo / first_temp_role_repo / TEST_DOCKERFILE_FROM — minimal valid role-repo fixtures for tests exercising validate_role_repo and role-registration temp-dir discovery.

Architecture tier and allowed dependencies

Test-support tier: sits just above jackin-core. Allowed workspace dependencies: jackin-core, jackin-manifest (both leaf/domain crates that do not depend on this crate or on jackin-runtime). Production crates must never depend on this crate — it is consumed via [dev-dependencies] only. Anyone's dev-deps may depend on it; it may depend only downward itself.

Structure

Module	Owns	Tests
`lib.rs`	crate root, re-exports	—
`runner.rs`	`FakeRunner`	—
`docker.rs`	`FakeDockerClient`	—
`seed.rs`	role-repo seed fixtures	—

Public API

FakeRunner, FakeDockerClient, seed_valid_role_repo, first_temp_role_repo, TEST_DOCKERFILE_FROM — all re-exported from the crate root. Moved byte-for-byte (behavior-preserving) from jackin-runtime's former runtime::test_support module; jackin-runtime's install_all_test_stubs stayed behind (it needs jackin_image and has no consumer outside jackin-runtime's own tests).

Dedupe candidates (follow-up, not done here)

Three fakes duplicate these types elsewhere in the workspace and were deliberately left in place by this extraction (different call sites, different plan):

crates/jackin/tests/common.rs — its own FakeRunner.
crates/jackin-host/src/caffeinate/tests.rs — its own FakeDockerClient + FakeRunner.
Console StubRunners (×4) — different trait, not a candidate.

Future Phase 3 test-support helpers (deterministic builders, snapshot normalization, fixed dims/theme, a ManualClock re-export) land here too, one PR each.

How to verify

cargo nextest run -p jackin-test-support
cargo clippy -p jackin-test-support --all-targets -- -D warnings
cargo tree -p jackin-test-support -i --edges normal   # inverse tree: no production crate should list it