Replace forbidden #[allow] attributes with narrowly-scoped #[expect] attributes

[coderabbitai]

Problem

The codebase contains multiple instances of #[allow] attributes which are forbidden per our coding guidelines. These need to be replaced with narrowly-scoped #[expect(lint, reason = "...")] attributes and annotated with FIXME comments.

Affected Files

The following files contain forbidden #[allow] attributes:

• tests/common/mod.rs (lines 22-29)
• wireframe_testing/src/logging.rs (lines 77-79)
• wireframe_testing/src/helpers.rs (lines 18-20)
• tests/session_registry.rs (lines 9-11 and 16-18)
• tests/push_policies.rs (lines 15-17)
• tests/extractor.rs (lines 13-15 and 20-22)
• tests/connection_actor.rs (lines 21-23, 28-30, 35-37)
• tests/app_data.rs (lines 14-16 and 21-23)
• examples/ping_pong.rs (lines 43-44: allow(clippy::unused_async))
• src/server/config/binding.rs (lines 26, 69, 141: allow(private_bounds))

Acceptance Criteria

• All #[allow(...)] attributes replaced with #[expect(...)]
• Each replacement includes a FIXME comment with issue reference
• Lint suppressions remain narrowly scoped to the smallest viable scope
• All existing functionality preserved
• Code passes make fmt, make lint, and make test

References

• PR: Refactor app into modular submodules #332
• Comment: Refactor app into modular submodules #332 (comment)
• Requested by: @leynos

[leynos]

@coderabbitai plan

[coderabbitai]

Coding Plan

Approach

Replace forbidden #[allow] attributes with #[expect] attributes where viable, and refactor rstest fixtures to multi-line format to eliminate the need for lint suppression workarounds entirely. The ticket's file list is partially inaccurate and requires correction based on actual codebase state.

Observations

This Rust codebase has strict lint policies configured in Cargo.toml with allow_attributes = "deny" and allow_attributes_without_reason = "deny". The codebase uses rstest for test fixtures, which causes false positive unused_braces lints on single-line fixtures. A workaround pattern exists using #[expect(clippy::allow_attributes)] + #[allow(unfulfilled_lint_expectations)], but converting single-line fixtures to multi-line format eliminates the need for any suppression. The tests/common/mod.rs file has documented crate-level #![allow] attributes that cannot be converted to #[expect] due to Rust limitations with shared test utilities.

Assumptions

Assumption 1: Ticket file list accuracy vs actual codebase state

Options Considered:

1. Follow the ticket's file list literally and investigate each listed file
2. Work from the actual #[allow] attributes found in the codebase, ignoring files that don't contain them

Chosen Option: 2

Rationale: Work from actual codebase state. The exploration confirmed that tests/connection_actor.rs doesn't exist (should be tests/connection_actor_errors.rs and tests/connection_actor_shutdown.rs), and several listed files contain no #[allow] attributes. Additionally, wireframe_testing/src/multi_packet.rs was missing from the ticket but does contain an #[allow] attribute.

Assumption 2: Approach for rstest fixture lint suppressions

Options Considered:

1. Keep the existing workaround pattern with improved documentation
2. Convert single-line fixtures to multi-line format to eliminate the lint issue entirely

Chosen Option: 2

Rationale: Refactoring single-line fixtures to multi-line format removes the unused_braces lint entirely, which eliminates the need for the entire workaround pattern. This aligns with the codebase philosophy of fixing issues rather than suppressing them.

Assumption 3: Handling tests/common/mod.rs crate-level allows

Options Considered:

1. Attempt to convert to #[expect] despite the documented limitations
2. Keep the existing #![allow] attributes with their FIXME(#333) documentation

Chosen Option: 2

Rationale: The existing documentation in tests/common/mod.rs explicitly explains that #[expect] fails inconsistently across test binaries due to Rust limitations. These are already properly documented with FIXME(#333) references and reason parameters.

💡 User Tips

Regenerate the plan with different choices with @coderabbitai <feedback>.

Implementation Steps

Phase 1: Refactor rstest Single-Line Fixtures to Multi-Line Format

This phase eliminates the need for lint suppression workarounds by restructuring fixtures so they don't trigger the unused_braces lint in the first place. Multi-line fixtures avoid the rustc false positive entirely.

Task 1: Refactor fixtures in tests/push_policies.rs

Convert the single-line fixture to multi-line format and remove the triple-attribute workaround pattern.

• Remove the #[expect(clippy::allow_attributes)], #[allow(unfulfilled_lint_expectations)], and #[expect(unused_braces)] attribute chain
• Reformat the builder() fixture to multi-line with the opening brace on the signature line
• Add an explanatory comment inside the function body describing the fixture's purpose

Task 2: Refactor fixtures in tests/app_data.rs

Convert both single-line fixtures to multi-line format and remove their workaround patterns.

• Remove the workaround attribute chains from both the request() and empty_payload() fixtures
• Reformat each fixture to multi-line with descriptive comments inside the function bodies
• Ensure the fixtures maintain identical behavior (just formatting changes)

Task 3: Refactor fixtures in tests/connection_actor_errors.rs

Convert the single-line fixtures to multi-line format and remove their workaround patterns.

• Identify the two fixtures with #[allow(unfulfilled_lint_expectations)] attributes
• Remove the workaround attribute chains from both fixtures
• Reformat to multi-line with explanatory comments

Task 4: Refactor fixtures in tests/connection_actor_shutdown.rs

Update the fixture defined within the macro to use multi-line format.

• Locate the fixture inside the macro definition that uses the workaround pattern
• Refactor the macro-generated fixture to multi-line format
• Remove the #[allow(unfulfilled_lint_expectations)] attribute from the macro

🤖 Prompt for AI agents

This phase refactors rstest fixtures from single-line to multi-line format to
eliminate the `unused_braces` lint entirely, removing the need for lint
suppression workarounds.

**For tests/push_policies.rs:**
- Locate the `builder()` fixture function
- Remove all three attributes: `#[expect(clippy::allow_attributes)]`,
`#[allow(unfulfilled_lint_expectations)]`, and `#[expect(unused_braces)]`
- Reformat the fixture to multi-line format with the opening brace on the same
line as the function signature
- Add an explanatory comment inside the function body describing what the
fixture provides

**For tests/app_data.rs:**
- Locate both the `request()` and `empty_payload()` fixture functions
- Remove the workaround attribute chains from both fixtures (same
three-attribute pattern)
- Reformat each fixture to multi-line format
- Add descriptive comments inside each function body
- Ensure the return values and behavior remain identical

**For tests/connection_actor_errors.rs:**
- Identify the two fixtures that have the
`#[allow(unfulfilled_lint_expectations)]` attribute
- Remove the entire workaround attribute chain from both fixtures
- Reformat both fixtures to multi-line format
- Add explanatory comments inside the function bodies

**For tests/connection_actor_shutdown.rs:**
- Locate the macro definition that generates a fixture with the workaround
pattern
- Modify the macro to generate multi-line fixture format instead of single-line
- Remove the `#[allow(unfulfilled_lint_expectations)]` attribute from the macro
template

Phase 2: Update Remaining Lint Suppressions

Handle the remaining #[allow] attributes that are not related to the rstest workaround pattern.

Task 1: Refactor fixture in wireframe_testing/src/logging.rs

Convert the single-line logger() fixture to multi-line format.

• Remove the #[allow(unused_braces, reason = "...")] attribute
• Reformat the logger() fixture function to multi-line with an explanatory comment
• This follows the same pattern as the test file refactoring

Task 2: Convert allow to expect in wireframe_testing/src/multi_packet.rs

Update the unstable feature lint suppression to use #[expect] with proper documentation.

• Replace #[allow(ungated_async_fn_track_caller)] with #[expect(ungated_async_fn_track_caller, reason = "track_caller on async fns is unstable; remove when stabilized")]
• Add a FIXME comment above the attribute referencing PR #332 or the appropriate tracking issue
• The inline comment can be removed since the reason parameter now documents the suppression

🤖 Prompt for AI agents

This phase addresses the remaining `#[allow]` attributes that are not part of
the rstest workaround pattern.

**For wireframe_testing/src/logging.rs:**
- Locate the `logger()` fixture function
- Remove the `#[allow(unused_braces, reason = "...")]` attribute
- Reformat the `logger()` fixture to multi-line format with the opening brace on
the signature line
- Add an explanatory comment inside the function body describing the fixture's
purpose
- This follows the same refactoring pattern as the test fixtures in Phase 1

**For wireframe_testing/src/multi_packet.rs:**
- Locate the `#[allow(ungated_async_fn_track_caller)]` attribute
- Replace it with `#[expect(ungated_async_fn_track_caller, reason =
"track_caller on async fns is unstable; remove when stabilized")]`
- Add a FIXME comment above the attribute that references PR `#332` or the
appropriate tracking issue for stabilization
- Remove any existing inline comments that document the suppression, as the
reason parameter now provides this documentation

Phase 3: Verify Documentation and Run Quality Checks

Ensure all changes preserve functionality and meet acceptance criteria.

Task 1: Verify tests/common/mod.rs documentation

Confirm the existing crate-level allows are properly documented and no changes are needed.

• Review that the #![allow(clippy::allow_attributes)] and #![allow(dead_code)] attributes have reason parameters
• Verify the FIXME(#333) comment adequately explains why #[expect] cannot be used
• No code changes expected; this is a verification task

Task 2: Run quality gates and verify acceptance criteria

Execute the full test and lint suite to ensure all changes pass.

• Run make fmt to ensure code formatting is correct
• Run make lint to verify no new lint warnings and the allow_attributes = "deny" rule passes
• Run make test to confirm all existing functionality is preserved
• Verify that all #[allow] attributes have been addressed (removed via refactoring or documented as unavoidable exceptions)

🤖 Prompt for AI agents

This phase verifies that all changes meet quality standards and acceptance
criteria.

**For tests/common/mod.rs verification:**
- Open the file and review the crate-level `#![allow]` attributes at the top
- Confirm that `#![allow(clippy::allow_attributes)]` has a reason parameter
explaining the limitation
- Confirm that `#![allow(dead_code)]` has a reason parameter
- Verify the FIXME(`#333`) comment adequately explains why `#[expect]` cannot be
used for shared test utilities
- This is a verification-only task; no code changes should be made

**For quality gates:**
- Run `make fmt` and verify the command succeeds with no formatting changes
needed
- Run `make lint` and verify:
  - No new lint warnings appear
  - The `allow_attributes = "deny"` rule passes successfully
  - All remaining `#[allow]` attributes have reason parameters
- Run `make test` and verify all tests pass
- Perform a final check that all `#[allow]` attributes in the codebase are
either:
  - Removed through refactoring (rstest fixtures)
  - Converted to `#[expect]` (multi_packet.rs)
  - Documented as necessary exceptions (tests/common/mod.rs)

---

🚀 Next Steps

🤖 All AI agent prompts combined

Task: 1

This phase refactors rstest fixtures from single-line to multi-line format to
eliminate the `unused_braces` lint entirely, removing the need for lint
suppression workarounds.

**For tests/push_policies.rs:**
- Locate the `builder()` fixture function
- Remove all three attributes: `#[expect(clippy::allow_attributes)]`,
`#[allow(unfulfilled_lint_expectations)]`, and `#[expect(unused_braces)]`
- Reformat the fixture to multi-line format with the opening brace on the same
line as the function signature
- Add an explanatory comment inside the function body describing what the
fixture provides

**For tests/app_data.rs:**
- Locate both the `request()` and `empty_payload()` fixture functions
- Remove the workaround attribute chains from both fixtures (same
three-attribute pattern)
- Reformat each fixture to multi-line format
- Add descriptive comments inside each function body
- Ensure the return values and behavior remain identical

**For tests/connection_actor_errors.rs:**
- Identify the two fixtures that have the
`#[allow(unfulfilled_lint_expectations)]` attribute
- Remove the entire workaround attribute chain from both fixtures
- Reformat both fixtures to multi-line format
- Add explanatory comments inside the function bodies

**For tests/connection_actor_shutdown.rs:**
- Locate the macro definition that generates a fixture with the workaround
pattern
- Modify the macro to generate multi-line fixture format instead of single-line
- Remove the `#[allow(unfulfilled_lint_expectations)]` attribute from the macro
template
===============================================================================

Task: 2

This phase addresses the remaining `#[allow]` attributes that are not part of
the rstest workaround pattern.

**For wireframe_testing/src/logging.rs:**
- Locate the `logger()` fixture function
- Remove the `#[allow(unused_braces, reason = "...")]` attribute
- Reformat the `logger()` fixture to multi-line format with the opening brace on
the signature line
- Add an explanatory comment inside the function body describing the fixture's
purpose
- This follows the same refactoring pattern as the test fixtures in Phase 1

**For wireframe_testing/src/multi_packet.rs:**
- Locate the `#[allow(ungated_async_fn_track_caller)]` attribute
- Replace it with `#[expect(ungated_async_fn_track_caller, reason =
"track_caller on async fns is unstable; remove when stabilized")]`
- Add a FIXME comment above the attribute that references PR `#332` or the
appropriate tracking issue for stabilization
- Remove any existing inline comments that document the suppression, as the
reason parameter now provides this documentation
===============================================================================

Task: 3

This phase verifies that all changes meet quality standards and acceptance
criteria.

**For tests/common/mod.rs verification:**
- Open the file and review the crate-level `#![allow]` attributes at the top
- Confirm that `#![allow(clippy::allow_attributes)]` has a reason parameter
explaining the limitation
- Confirm that `#![allow(dead_code)]` has a reason parameter
- Verify the FIXME(`#333`) comment adequately explains why `#[expect]` cannot be
used for shared test utilities
- This is a verification-only task; no code changes should be made

**For quality gates:**
- Run `make fmt` and verify the command succeeds with no formatting changes
needed
- Run `make lint` and verify:
  - No new lint warnings appear
  - The `allow_attributes = "deny"` rule passes successfully
  - All remaining `#[allow]` attributes have reason parameters
- Run `make test` and verify all tests pass
- Perform a final check that all `#[allow]` attributes in the codebase are
either:
  - Removed through refactoring (rstest fixtures)
  - Converted to `#[expect]` (multi_packet.rs)
  - Documented as necessary exceptions (tests/common/mod.rs)

💡 Iterate on the plan with: @coderabbitai <feedback>

Example Feedback
- `@coderabbitai` You can skip phase 3. Add a simple unit test case for phase 2.
- `@coderabbitai` For assumption 1 go ahead with option 3 and replan.

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