[dotnet] Annotate nullability on FirefoxDriverService

[RenderMichael]

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Annotate nullability on FirefoxDriverService

Motivation and Context

Contributes to #14640

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

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PR Type

Enhancement

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Description

• Annotated nullability for properties and parameters in FirefoxDriverService.

• Simplified property definitions using auto-implemented properties.

• Enabled nullable reference types with #nullable enable.

• Refactored command-line argument generation for better readability.

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Changes walkthrough 📝

	Relevant files
Enhancement	FirefoxDriverService.cs Annotated nullability and refactored `FirefoxDriverService`. dotnet/src/webdriver/Firefox/FirefoxDriverService.cs Enabled nullable reference types with #nullable enable. Annotated properties and parameters with nullable types. Replaced backing fields with auto-implemented properties. Refactored logic for command-line argument generation. +29/-59

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[qodo-merge-pro]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 2 🔵🔵⚪⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Null Reference The GetDirectoryName call on line 203 assumes the path has a directory component and uses the null-forgiving operator (!), but this assumption should be validated to prevent runtime errors. driverPath = Path.GetDirectoryName(driverPath)!;

[qodo-merge-pro]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Score
Possible issue	✅ Add null check for path Suggestion Impact: The commit implemented a null check for Path.GetDirectoryName() using null-coalescing operator with throw, achieving the same goal as the suggestion but with slightly different syntax code diff: - driverPath = Path.GetDirectoryName(driverPath)!; + driverPath = Path.GetDirectoryName(driverPath) ?? throw new ArgumentException("Driver file exists but parent directory is unreachable", nameof(driverPath)); Add null check for Path.GetDirectoryName() result since it can return null for invalid paths. The current forced null-forgiving operator (!) could lead to NullReferenceException. dotnet/src/webdriver/Firefox/FirefoxDriverService.cs [203] -driverPath = Path.GetDirectoryName(driverPath)!; +var dirPath = Path.GetDirectoryName(driverPath); +if (dirPath == null) throw new ArgumentException("Invalid driver path provided", nameof(driverPath)); +driverPath = dirPath; Apply this suggestion Suggestion importance[1-10]: 8 Why: The suggestion addresses a potential null reference exception by properly handling the case where Path.GetDirectoryName returns null, which is a critical safety check for path operations.	8
General	Validate port number range Add input validation for BrowserCommunicationPort to ensure it's within valid port range (1-65535) when setting a positive value. dotnet/src/webdriver/Firefox/FirefoxDriverService.cs [64] -public int BrowserCommunicationPort { get; set; } = -1; +private int _browserCommunicationPort = -1; +public int BrowserCommunicationPort +{ + get => _browserCommunicationPort; + set + { + if (value > 0 && (value < 1 || value > 65535)) + throw new ArgumentOutOfRangeException(nameof(value), "Port must be between 1 and 65535"); + _browserCommunicationPort = value; + } +} Apply this suggestion Suggestion importance[1-10]: 7 Why: The suggestion adds important validation to ensure port numbers are within valid range (1-65535), preventing potential runtime errors from invalid port assignments.	7

[RenderMichael]

Failures are not related to changes in this PR:

//java/test/org/openqa/selenium/mobile:NetworkConnectionTest
//java/test/org/openqa/selenium/remote:RemoteWebDriverScreenshotTest
//java/test/org/openqa/selenium/remote:RemoteWebDriverScreenshotTest-firefox-beta