Summary

This PR introduces a new comprehensive test suite for theMemoryUsage extension intests/test_memusage.py,Fixes#7002.

Coverage

• Extension Initialization

  • Enabled only whenMEMUSAGE_ENABLED = True
  • Default/custom settings initialization
  • RaisesNotConfigured whenresource module is unavailable

• Memory Size Calculation

  • get_virtual_size() behavior on macOS (bytes) and Linux (KB)
  • Properly mocksresource.getrusage()

• Signal Handlers

  • engine_started() with and without memory limits
  • engine_stopped() ensures tasks are properly stopped
  • Correct creation of looping tasks based on settings

• Memory Monitoring

  • update() correctly updates stats
  • _check_limit() for exceeded/non-exceeded cases
  • Handles scenarios with/without active spiders
  • "Warn once" behavior properly respected

• Notifications

  • Email notifications for limit and warning thresholds
  • Proper subject formatting and hostname inclusion
  • _send_report() includes engine status and memory info

• Edge Cases

  • Behavior when no limits are set
  • Warnings only sent once
  • Different memory threshold scenarios tested

Test Quality

• Proper use ofunittest.mock for external deps (resource, email sending, crawler components)
• Parametrized tests viapytest.mark.parametrize
• Consistent with Scrapy’s testing style
• Platform-specific behavior tested (Linux vs macOS)
• Covers happy path and edge cases

Results

• ✅ 22 tests passing locally
• ⚠️ 2 harmless warnings about un-awaited mocked async coroutines (expected in test context, no functional impact)

Notes

This suite ensures MemoryUsage extension is fully validated, improves confidence in its stability, and aligns with Scrapy’s test patterns.