Add testing and cross-package consistency guidance.

context/conventions.md

@@ -52,6 +52,16 @@ concept within the crate.
   after the item using lowercase `snake_case`. Keep small, closely related
   helper types alongside it when that makes the code easier to understand.
 
+## Consistency across packages
+
+Before introducing a new semantic, layout, or naming pattern, check how related
+Socketry packages handle the same concern. Reuse an established pattern when it
+fits the package's purpose. When a package establishes or changes a pattern,
+document the rationale and intended usage in that package's context so later
+work has a reference. Preserve differences that reflect real domain needs;
+consistency should make related packages easier to understand, not flatten
+their APIs into one shape.
+
 ## Source and documentation
 - Keep authored repository-root Markdown files to lowercase `readme.md`,
   `license.md`, and `releases.md`.

context/layout.md

@@ -87,6 +87,6 @@ Put runnable examples under `examples/`. Store project tool configuration in a
 clearly named configuration file or the relevant Cargo metadata; avoid adding
 a configuration directory without a concrete tool that uses it.
 
-For testing expectations and task details, see [Testing](testing.md) and the
-installed `bake-test-rust` context. Use the [setup skill](setup.md) for
-workflow setup.
+Follow the `socketry-project-testing` skill for testing expectations and
+consult the installed `bake-test-rust` context for task and workflow details.
+Use the [setup skill](setup.md) for workflow setup.

context/setup.md

@@ -59,7 +59,6 @@ The `socketry-project` dependency makes the shared tasks available to the
 private Bake binary. It also registers `cargo:after_version_bump`, which updates
 `license.md`, `releases.md`, and generated sections in `readme.md` after a
 version change.
-It bundles the standard `test` and `test:external` task providers as well.
 Keep task tooling out of unrelated published libraries. Consumer projects
 should depend on `socketry-project` from their private `bake/` package.
 
@@ -80,29 +79,21 @@ Generate the Cargo workflow with `cargo:setup:workflow`; follow the
 before applying rulesets, environment reviewers, or crates.io trusted
 publishing.
 
-## Standard workflows
+## Test workflows
 
-Keep `.github/workflows/test.yml` for local workspace tests. When
-`bake-test-rust` is linked, install the Cargo launcher and run
-`cargo bake --locked test` so the optional `test:before` hook also runs.
-Otherwise use `cargo test --workspace --locked`. Add platform or feature
-matrix entries when the project needs them.
-
-List selected downstream projects under
-`[workspace.metadata.bake.test.external]` in the root `Cargo.toml`. Add
-`.github/workflows/external.yml` only when that list is non-empty, and run
-`cargo bake --locked test:external` when `bake-test-rust` is linked. The task
-keeps checkouts under `external/` and applies local workspace crates as Cargo
-patches so downstream tests exercise the source being developed.
+Use the `socketry-project-testing` skill for organization-wide testing
+expectations. Consult the installed `bake-test-rust` context for canonical
+`test.yml` and optional `external.yml` workflows, task setup, coverage options,
+and downstream test configuration.
 
 Use `cargo:setup:workflow` from `bake-cargo` to generate
 `.github/workflows/publish.yml`. That workflow checks a release candidate on
 pull requests, publishes after merge through the configured `crates-io`
 environment, and then creates or updates the matching GitHub Release from
 `releases.md`. See the [Cargo Publishing guide](https://github.com/socketry/bake-cargo-rust/blob/main/context/publishing.md)
-for trusted publishing and repository setup. See the Rust Testing context
-guide provided by `socketry-project` for test workflow details and optional
-downstream compatibility workflows.
+for trusted publishing and repository setup. Use the
+`socketry-project-testing` skill for testing expectations and the
+`bake-test-rust` context for workflow and task details.
 
 ## Work on the project
 

context/testing.md

@@ -1,19 +1,33 @@
-# Testing
+---
+type: skill
+description: Add or update tests in Socketry Rust projects, require 100% line coverage, and decide when downstream compatibility tests are useful. Use when asked to add tests or when behavior changes need regression coverage.
+---
 
-Every Rust project should include tests for its public behavior and maintain
-100% line coverage for compiled workspace targets. Organize unit, integration,
-and documentation tests according to the [Rust repository layout guide](layout.md#test-layout).
+# Testing Socketry Rust Projects
 
-Use the shared `bake-test-rust` tasks from the private `bake/` package. The
-`test:coverage` task is the canonical CI test entry point: it runs the tests and
-enforces the line coverage requirement. Add `--all-targets true` when examples
-and benchmarks should also be included.
+Use this skill whenever a change adds or changes behavior that should be
+verified by tests.
 
-External compatibility tests are optional. List selected downstream projects
-in Cargo metadata and add an external test workflow only when the list is
-nonempty.
+## Expectations
 
-Consult the installed
-`.agents/context/bake-test-rust/testing.md` for task configuration, local and
-CI commands, coverage setup, `test:before`, and external test details. That
-guide owns the canonical workflow and the mechanics for using the tasks.
+- Add tests that exercise the changed behavior and relevant regression cases.
+- Require 100% line coverage for supported target and feature configurations.
+  Use the coverage report to find and cover every executable source line.
+- Treat uncovered code as an opportunity to review semantics. Check that its
+  behavior is correct, and fix defects rather than writing tests that codify
+  accidental behavior.
+- Run coverage on each supported target or configuration that compiles distinct
+  platform-specific code.
+- Consider external compatibility tests when a change could affect downstream
+  crates that use this project's public API. Select the relevant consumers;
+  downstream testing is not required for every change.
+
+Follow the repository's test layout guidance when choosing between unit and
+integration tests.
+
+## Use the shared testing tasks
+
+Use the shared Bake test tasks for local verification and CI. Consult the
+installed `bake-test-rust` context at
+`.agents/context/bake-test-rust/testing.md` for canonical workflow files, task
+setup and invocation, coverage options, and downstream test configuration.

context/update.md

@@ -25,6 +25,9 @@ initial setup steps.
 Review the repository's Cargo manifests, source and test layout, standard root
 files, Bake package, agent context, and GitHub workflows. Compare them with the
 current guidance in `socketry-project` and the relevant shared task packages.
+Compare semantics, layout, and naming with related Socketry packages. Reuse
+patterns that fit; when this package establishes a new pattern, document its
+rationale and intended usage in the package context.
 
 Check these areas:
 

readme.md

@@ -35,9 +35,9 @@ version-bump hook that updates the project's standard files.
 See the [repository setup skill](context/setup.md) for the minimal Cargo
 configuration and the [conventions](context/conventions.md) for repository
 layout, documentation, and code conventions. The
-[Rust Repository Layout](context/layout.md) and
-[Rust Testing](context/testing.md) guides provide more detail on source
-organization and test workflows.
+[Rust Repository Layout](context/layout.md) explains source organization. The
+testing skill sets expectations and points to `bake-test-rust` for task and
+workflow details.
 
 ## Releasing
 

releases.md

@@ -1,5 +1,13 @@
 # Releases
 
+## Unreleased
+
+- Add a testing skill that sets the 100% line-coverage expectation and directs
+  agents to review uncovered code for semantic defects and use `bake-test-rust`
+  for canonical workflows and task details.
+- Document how to maintain consistency across Socketry packages and record new
+  semantic, layout, and naming patterns in the package that establishes them.
+
 ## v0.3.0
 
 - Add an update skill for auditing and modernizing existing Socketry Rust