Test strategy and crate audit¶

Tests are evidence for supported behavior, not a second implementation or a historical archive. Put each assertion at the lowest boundary that can prove the contract.

Test levels¶

Level	Use it for	Location
Unit	Pure rules, parsing, state transitions, bounded rendering, and adapter-local failure	Next to the module or in `src/tests.rs` / `src/tests/`
Integration	Public crate boundaries, persistence conformance, subprocess protocols, platform isolation, and live adapters	`<crate>/tests/`
End to end	Installed CLI, worker, Desktop, SDK, release, and operator workflows	CLI/Desktop suites and CI workflows

Do not promote a unit test to a process test merely for realism. Do not replace a security, protocol, persistence, or packaging boundary test with a mock merely for speed. An ignored live test is acceptable only when its prerequisite is explicit and a named CI job or documented operator command owns its execution.

Crate-by-crate audit¶

This inventory records the August 2026 Rust-cutover cleanup. “Keep” means the suite protects a current boundary; it does not mean every future assertion is permanent.

Crate	Test ownership and disposition
`colossus-access`	Keep profile resolution, action precedence, and tool-ceiling unit tests.
`colossus-agent`	Keep turn-loop, tool, cancellation, and observability tests; the separate observability target proves exported signals.
`colossus-api-proto`	Keep generated-contract and compatibility tests for the public protocol.
`colossus-api-runtime`	Keep service authorization, streaming, enrollment, and repository integration tests.
`colossus-api`	Keep server composition and public API lifecycle tests.
`colossus-audit`	Keep journal export, retry, recovery, and live WORM acceptance tests.
`colossus-cli`	Keep command-level smoke suites because they exercise public parsing and embedded/worker boundaries; remove a suite only when its command or contract is removed.
`colossus-codex-auth`	Keep OAuth/device-flow parsing, storage, and redaction tests.
`colossus-context`	Keep compaction budgets, snapshots, and deterministic fallback unit tests.
`colossus-contracts`	Keep serialization, validation, and stable contract-shape tests.
`colossus-darwin-process`	Keep platform process-isolation and limit tests on macOS CI.
`colossus-domain`	Keep dependency-free domain invariant tests.
`colossus-fuzzing`	Keep corpus regressions and fuzz harness compilation; they cover hostile parsers.
`colossus-grpc`	Keep transport translation, authentication, and stream-boundary tests.
`colossus-home`	Keep confinement, workspace identity, permissions, and symlink-escape tests.
`colossus-integrations`	Keep manifest, credential, dispatch, and live Splunk MCP acceptance tests.
`colossus-journal-postgres`	Keep shared journal conformance, transaction ownership, outage, and recovery tests.
`colossus-journal-redb`	Keep shared journal conformance, encryption, tamper, migration, and crash-recovery tests; retained on-disk readers protect current state.
`colossus-mcp`	Keep strict configuration, protocol, OAuth, tool ceiling, and subprocess/remote tests.
`colossus-memory-chroma`	Keep projection/retry tests and the opt-in live Chroma target.
`colossus-memory`	Keep canonical lifecycle, scope, Tantivy projection, and fallback tests.
`colossus-network`	Keep DNS pinning, redirects, trust roots, response bounds, and authority tests.
`colossus-observability`	Keep disabled-by-default, redaction, payload-mode, and exporter tests.
`colossus-packs`	Keep signature, permission-ceiling, archive, dependency, and no-clobber tests.
`colossus-policy`	Keep built-in and OPA decision tests, including opt-in live and mTLS targets.
`colossus-ports`	Keep reusable port-conformance helpers; avoid adapter behavior here.
`colossus-presentation`	Keep pure document/theme/rendering tests; the obsolete Python theme-import test was removed.
`colossus-projection`	Keep deterministic projection, checkpoint, and rebuild tests.
`colossus-provider`	Keep provider translation, streaming, limits, malformed output, and redaction tests.
`colossus-research`	Keep evidence bounds, citations, lane failures, and deterministic fallback tests.
`colossus-runtime`	Keep composition and cross-service security tests; obsolete `research.search` compatibility assertions were removed.
`colossus-sandbox`	Keep native/OCI/Windows contract, broker, cleanup, and hostile-input tests.
`colossus-sdk`	Keep embedded/native-sidecar/gRPC parity and subprocess lifecycle tests.
`colossus-search`	Keep SearXNG/SerpAPI parsing, credentials, bounds, and role-routing tests.
`colossus-session`	Keep message, branch, restore, and context-view repository tests.
`colossus-sidecar-protocol`	Keep authenticated framing and workspace-identity compatibility tests; they protect deployed sidecars.
`colossus-sidecar`	Keep native and Windows bootstrap/lifecycle acceptance targets.
`colossus-skills`	Keep discovery, precedence, validation, confinement, and authoring tests.
`colossus-telemetry`	Keep durable event, query, retention, and bounded-export tests.
`colossus-testkit`	Keep shared conformance tests and fixtures used by adapter crates.
`colossus-tools`	Keep schema-first validation, gateway adapters, confinement, output, and mutation tests.
`colossus-tui`	Keep reducer, layout, input, theme, restoration, and PTY history tests; they cover behavior not proved by snapshots alone.
`colossus-update`	Keep release metadata, signature, channel, and atomic-update tests.
`colossus-windows-native`	Keep AppContainer/native binding tests on Windows CI.
`colossus-windows-process`	Keep Job Object, memory pressure, cleanup, and process-tree tests on Windows CI.
`colossus-work`	Keep durable task, decision, plan, and goal lifecycle tests.
`colossus-worker-protocol`	Keep versioned authenticated request/prompt/cancellation/replay tests.
`colossus-worker`	Keep worker composition, authentication, shutdown, and restart tests.
`colossus-workflow`	Keep parsing, control flow, recovery, triggers, idempotency, and compensation tests.

The CLI integration directory contains intentionally separate suites for agent, approval, audit export, authentication, bootstrap/install, bundles, configuration, context, documentation examples, integrations, MCP, native/OCI/Windows sandboxing, packs, plans, providers, release installation, research, search, skills, rejection, worker, and workflow behavior. Their separation lets CI select expensive prerequisites without weakening the public-boundary assertions.

Removal criteria¶

Remove or rewrite a test when its product behavior has been deliberately removed, it duplicates stronger evidence at the same boundary, it asserts implementation detail without a contract, or its fixture describes a format Colossus explicitly rejects. Keep historical storage or protocol readers only while current deployments can present those formats; record a later removal decision before deleting that evidence.

Verification tiers¶

During iteration, run the changed crate's library tests and directly affected targets. Then use cargo xtask dev, cargo xtask check rust, and finally cargo xtask pr --base origin/main. See Source setup and test tiers for prerequisites and CI mapping.