Tests: Add 11 missing UnitConverters unit tests

[PureWeen]

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Summary

Add unit tests for 11 UnitConverters methods that had no test coverage.

New test cases cover: FahrenheitToCelsius, CelsiusToFahrenheit, CelsiusToKelvin, KelvinToCelsius, MilesToMeters, DegreesPerSecondToHertz, RadiansPerSecondToHertz, HertzToDegreesPerSecond, HertzToRadiansPerSecond, KilopascalsToPascals, and HectopascalsToPascals.

✅ dotnet test src/Essentials/test/UnitTests/Essentials.UnitTests.csproj --filter UnitConverters — 168 passed, 0 failed.

[github-actions]

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[Copilot]

Pull request overview

Adds missing unit test coverage for several Microsoft.Maui.Media.UnitConverters conversion methods in Essentials, improving confidence in basic numeric conversion helpers.

Changes:

• Added theories for Fahrenheit↔Celsius and Celsius↔Kelvin conversions
• Added theories for Miles→Meters and angular velocity ↔ frequency conversions (deg/s, rad/s, Hz)
• Added theories for Kilopascals/Hectopascals → Pascals conversions

[kubaflo]

/review

[github-actions]

✅ Expert Code Review completed successfully!

[github-actions]

Expert Code Review — 3-Reviewer Adversarial Consensus

Findings

🟡 MODERATE — PR description does not match the actual changes (3/3 reviewers)

The PR description claims tests were added for: CelsiusToKelvin, KelvinToCelsius, MilesToMeters, MetersToMiles, KilometersToMiles, MilesToKilometers, DegreesToRadians, RadiansToDegrees, PoundsToKilograms, KilogramsToPounds, AtmospheresToPascals.

However, comparing against the existing file and the implementation in UnitConverters.shared.cs:

Claimed in description	Actual status
MetersToMiles	❌ Method does not exist in UnitConverters.shared.cs
KilometersToMiles	Already had tests
MilesToKilometers	Already had tests
DegreesToRadians	Already had tests
RadiansToDegrees	Already had tests
PoundsToKilograms	Already had tests
KilogramsToPounds	Already had tests
AtmospheresToPascals	Already had tests

Tests actually added (8 of which are not mentioned in the description):
FahrenheitToCelsius, CelsiusToFahrenheit, CelsiusToKelvin, KelvinToCelsius, MilesToMeters, DegreesPerSecondToHertz, RadiansPerSecondToHertz, HertzToDegreesPerSecond, HertzToRadiansPerSecond, KilopascalsToPascals, HectopascalsToPascals

Recommendation: Update the PR description to accurately list the 11 methods being tested, and remove the reference to the non-existent MetersToMiles.

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🟢 MINOR — MilesToMeters missing negative input case (2/3 reviewers)

See inline comment. The existing MilesToKilometers test includes [InlineData(-1, -1.6093)]; the new MilesToMeters test only covers non-negative values. Adding a negative case would maintain consistency.

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🟢 MINOR — Frequency conversion tests could use more coverage (2/3 reviewers)

See inline comment. RadiansPerSecondToHertz has only 3 test cases (vs 4–5 for other tests), and the frequency conversion tests don't include negative inputs unlike other converter tests in the file.

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Discarded — CelsiusToKelvin/KelvinToCelsius body-temperature case (1/3 reviewers, follow-up disagreed)

One reviewer suggested adding body-temperature anchor cases (37°C ↔ 310.15 K). Two follow-up reviewers independently disagreed: the existing test points (absolute zero, boiling, 0 K, room temp) already validate the linear offset formula adequately, and body-temp is meaningful for the Fahrenheit fractional multiplier but redundant for Kelvin's simple + 273.15.

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Test Quality & CI Assessment

• ✅ All InlineData values verified mathematically correct against the implementation constants
• ✅ Precision parameter (, 4) is consistent with existing tests in the file
• ✅ Test patterns ([Theory] + [InlineData], parameter naming) follow established conventions
• ✅ This is a test-only PR — no production code changes to validate
• i️ PR reports 168 tests passed, 0 failed

Methodology

3 independent reviewers with adversarial consensus. Disputed findings (flagged by only 1 reviewer) were evaluated by the other 2 reviewers as follow-up. Only findings with ≥2/3 agreement are included.

Generated by Expert Code Review for issue #35191 · ● 7.9M

[kubaflo]

Addressed review feedback:

• PR description: Updated to accurately list the 11 methods actually covered (Fahrenheit/Celsius, Celsius/Kelvin, MilesToMeters, frequency conversions, Kilo-/Hectopascals → Pascals).
• MilesToMeters: Added negative case [InlineData(-1, -1609.344)] for parity with sibling tests.
• RadiansPerSecondToHertz: Added multi-revolution case [InlineData(12.5664, 2.0000)].
• Frequency tests (DegreesPerSecondToHertz, RadiansPerSecondToHertz, HertzToDegreesPerSecond, HertzToRadiansPerSecond): Added one negative case each for sign-handling coverage consistency.