Add test for strict priority when fairness disabled

[leynos]

Summary

• verify scheduler consumes all high priority frames first even if queued after low priority frames
• replace unwraps with expects in fairness_disabled_ignores_arrival_order test for clarity

Testing

• make lint
• make test

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https://chatgpt.com/codex/tasks/task_e_6869d1ea1a508322a090b3daba60809c

Summary by Sourcery

Refactor and extend the fairness-disabled scheduler test to verify that high-priority frames are always processed before low-priority frames regardless of arrival order, using a new Priority enum and rstest parameterization.

Tests:

• Introduce a Priority enum and rstest cases to parameterize arrival sequences in the fairness_disabled_processes_all_high_first test
• Refactor the test to push frames in a loop based on priority cases with descriptive expect messages

[sourcery-ai]

Reviewer's Guide

This PR enhances the existing test by parameterizing frame arrival order with a new Priority enum and refactors the push logic into a loop with expect-based error handling to verify that high-priority frames are always consumed first when fairness is disabled.

File-Level Changes

Change	Details	Files
Parameterize the fairness_disabled test with a Priority enum and multiple cases	Define a Priority enum with High and Low variants Add #[case] attributes listing different high/low sequences Update test signature to accept a Vec order	tests/connection_actor.rs
Refactor push logic into a loop matching on Priority and replace unwraps with expects	Initialize separate iterators for high and low frame numbers Loop over the order and use match to call push_high or push_low Swap unwrap calls for await with expect and formatted error messages	tests/connection_actor.rs

Possibly linked issues

• Fix instrumentation wording #123: PR adds test verifying high-priority frames process first when fairness disabled, fulfilling issue requirement.

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[coderabbitai]

Summary by CodeRabbit

• Tests
  • Improved test coverage by introducing parameterised tests for message priority order.
  • Added a new enum to represent message priorities, enhancing test clarity and flexibility.

Walkthrough

A new Priority enum was introduced in the test module to represent message priority. The test fairness_disabled_processes_all_high_first was refactored to be parameterised, allowing different sequences of high and low priority messages to be tested dynamically rather than using a fixed order.

Changes

File(s)	Change Summary
tests/connection_actor.rs	Added Priority enum; refactored and parameterised the fairness_disabled_processes_all_high_first test to accept dynamic message orderings.

Sequence Diagram(s)

sequenceDiagram
    participant TestCase
    participant PushQueues
    participant ConnectionActor

    TestCase->>PushQueues: Push messages in specified priority order
    TestCase->>ConnectionActor: Create actor with fairness disabled
    ConnectionActor->>PushQueues: Process messages
    TestCase->>ConnectionActor: Await completion and assert output order

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Possibly related PRs

• Add fairness counter for low-priority queue #145: Implements and tests the fairness mechanism in ConnectionActor, modifying the same test file and focusing on priority handling.
• Add fairness disabled test #176: Introduces the original fairness_disabled_processes_all_high_first test, which this PR now parameterises and extends.

Suggested reviewers

• codescene-delta-analysis

Poem

In the warren of tests, a new enum appears,
Priority hops in, to sort out our fears.
High and low messages, shuffled with glee,
Parameterised order, as fair as can be.
The actor now listens, the queues in a row—
A rabbit’s delight to see progress flow! 🐇

---

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🔇 Additional comments (4)

tests/connection_actor.rs (4)

74-78: LGTM: Well-defined test utility enum.

The Priority enum provides a clear abstraction for test parameterization, enabling different message arrival order scenarios to be tested systematically.

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81-82: LGTM: Excellent test parameterization.

The two test cases effectively cover different scenarios:

• Case 1: High-priority messages arrive first, then low-priority
• Case 2: Low-priority messages arrive first, then high-priority

This ensures the scheduler correctly prioritises high-priority messages regardless of arrival order when fairness is disabled.

---

85-85: LGTM: Proper rstest parameterization.

The function signature correctly accepts the parameterized order vector, following rstest conventions.

---

95-110: LGTM: Robust dynamic message pushing logic.

The refactored logic correctly:

• Uses separate iterators for high and low priority messages
• Maintains proper numbering (1-3 for high, 4-5 for low)
• Follows coding guidelines by using .expect() with descriptive messages
• Handles both parameterized test cases appropriately

The implementation ensures that regardless of the input order, the scheduler processes all high-priority messages before low-priority ones when fairness is disabled.

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[sourcery-ai]

Hey @leynos - I've reviewed your changes - here's some feedback:

• Consider adding an interleaved sequence (e.g., [High, Low, High, Low, …]) to ensure the scheduler always processes all highs before lows regardless of arrival pattern.
• Add boundary cases with only high-priority or only low-priority frames to verify the scheduler handles empty queues correctly.

Prompt for AI Agents

Please address the comments from this code review:
## Overall Comments
- Consider adding an interleaved sequence (e.g., [High, Low, High, Low, …]) to ensure the scheduler always processes all highs before lows regardless of arrival pattern.
- Add boundary cases with only high-priority or only low-priority frames to verify the scheduler handles empty queues correctly.

---

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[leynos]

@coderabbitai Please create new GitHub issues for the following, ensuring that sufficient context is included for understandability:

• Add an interleaved sequence (e.g., [High, Low, High, Low, …]) to ensure the scheduler always processes all highs before lows regardless of arrival pattern.
• Add boundary cases with only high-priority or only low-priority frames to verify the scheduler handles empty queues correctly.

[coderabbitai]

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For best results, initiate chat on the files or code changes.

🧩 Analysis chain

@leynos, I'll create two GitHub issues for the test enhancements you've requested. Let me gather the necessary information and create them with sufficient context.

---

🏁 Script executed:

#!/bin/bash
# Create GitHub issue for interleaved sequence testing
gh issue create \
  --title "Add interleaved priority sequence test for scheduler fairness disabled behavior" \
  --body "## Background

This issue is a follow-up to PR #189 which adds parameterized tests for scheduler priority behavior when fairness is disabled.

## Problem

The current test cases in \`tests/connection_actor.rs\` only cover two scenarios:
1. High-priority frames arriving first, then low-priority frames
2. Low-priority frames arriving first, then high-priority frames

We need more comprehensive testing to ensure the scheduler correctly processes all high-priority frames before low-priority frames regardless of complex arrival patterns.

## Proposed Solution

Add an interleaved sequence test case to the existing parameterized test \`fairness_disabled_processes_all_high_first\` in \`tests/connection_actor.rs\`.

Example interleaved pattern: \`[High, Low, High, Low, High]\`

This would verify that even when high and low priority frames are interleaved in the arrival order, the scheduler still processes all high-priority frames (1, 3, 5) before any low-priority frames (2, 4).

## Acceptance Criteria

- [ ] Add a new test case with interleaved priority sequence to the existing parameterized test
- [ ] Ensure the test verifies all high-priority frames are processed before low-priority frames
- [ ] Test should pass with the current scheduler implementation
- [ ] Follow existing code patterns and use the \`Priority\` enum

## Context

- **Related PR**: #189
- **Test file**: \`tests/connection_actor.rs\`
- **Function**: \`fairness_disabled_processes_all_high_first\`
- **Current test cases**: High-first and Low-first patterns

## Implementation Notes

The test should use the existing \`Priority\` enum and follow the same pattern as the current parameterized test cases using \`#[case]\` attributes with rstest.

**Backlinks**:
- PR: https://github.com/leynos/wireframe/pull/189
- Requested by: @leynos" \
  --assignee leynos

# Create GitHub issue for boundary cases
gh issue create \
  --title "Add boundary case tests for scheduler with homogeneous priority queues" \
  --body "## Background

This issue is a follow-up to PR #189 which adds parameterized tests for scheduler priority behavior when fairness is disabled.

## Problem

The current test cases in \`tests/connection_actor.rs\` only test scenarios with mixed priority frames. We need boundary case testing to ensure the scheduler handles edge cases correctly when queues contain only high-priority or only low-priority frames.

## Proposed Solution

Add boundary case test scenarios to verify the scheduler handles empty queues correctly when:
1. Only high-priority frames are present
2. Only low-priority frames are present

These tests should verify that the scheduler processes frames correctly without attempting to access empty queues of the opposite priority.

## Acceptance Criteria

- [ ] Add test case with only high-priority frames (e.g., \`[High, High, High]\`)
- [ ] Add test case with only low-priority frames (e.g., \`[Low, Low, Low]\`)
- [ ] Verify frames are processed in the correct order (should maintain arrival order within same priority)
- [ ] Ensure no runtime errors occur when one priority queue is empty
- [ ] Tests should pass with the current scheduler implementation
- [ ] Follow existing code patterns and use the \`Priority\` enum

## Context

- **Related PR**: #189
- **Test file**: \`tests/connection_actor.rs\`
- **Function**: \`fairness_disabled_processes_all_high_first\` (or create new test function if needed)
- **Current test focus**: Mixed priority scenarios

## Implementation Notes

These boundary cases could be added as additional \`#[case]\` attributes to the existing parameterized test, or as separate test functions if the logic differs significantly.

Consider edge cases like:
- Empty queues of opposite priority
- Proper iterator handling when one priority type is absent
- Maintaining arrival order within the same priority level

**Backlinks**:
- PR: https://github.com/leynos/wireframe/pull/189
- Requested by: @leynos" \
  --assignee leynos

Length of output: 4094

---

Perfect! I've successfully created two GitHub issues for the test enhancements you requested:

Issue #190: Add interleaved priority sequence test for scheduler fairness disabled behavior

• Focuses on adding comprehensive interleaved sequence testing (e.g., [High, Low, High, Low, High])
• Ensures the scheduler processes all high-priority frames before low-priority ones regardless of complex arrival patterns
• Provides clear context about the current test limitations and proposed solution

Issue #191: Add boundary case tests for scheduler with homogeneous priority queues

• Addresses edge cases with only high-priority or only low-priority frames
• Ensures proper handling of empty queues when one priority type is absent
• Includes acceptance criteria for maintaining arrival order within the same priority level

Both issues include:

• ✅ Comprehensive background and problem description
• ✅ Clear acceptance criteria with checkboxes
• ✅ Implementation notes and context
• ✅ Proper backlinks to PR Add test for strict priority when fairness disabled #189 and your username
• ✅ Assignment to you (@leynos)
• ✅ Technical details about the test file and existing Priority enum

The issues are ready for implementation and provide sufficient context for understanding the requirements and scope of work needed.

[leynos]

@coderabbitai review

[coderabbitai]

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