[dotnet] Annotate nullability on WebDriver.SessionId

[RenderMichael]

User description

Description

Annotate nullability on WebDriver.SessionId and the related interface IHasSessionId.

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

• Enabled nullable reference types in WebDriver and IHasSessionId.

• Annotated SessionId property with nullability support.

• Improved code clarity and null safety in WebDriver.

• Added #nullable enable directives to relevant files.

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Changes walkthrough 📝

Relevant files

Enhancement

IHasSessionId.cs Enable nullable reference types in `IHasSessionId`              dotnet/src/webdriver/IHasSessionId.cs Enabled nullable reference types in the file. Added #nullable enable directive at the namespace level. +2/-0      WebDriver.cs Enable nullable reference types in `WebDriver`                      dotnet/src/webdriver/WebDriver.cs Enabled nullable reference types in the file. Annotated SessionId property for nullability. Removed redundant #nullable restore directive. Improved null safety in Dispose method. +3/-7

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[qodo-merge-pro]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🎫 Ticket compliance analysis 🔶 14640 - Partially compliant Compliant requirements: Added nullability annotations to WebDriver.SessionId and IHasSessionId Enabled nullable reference types in the modified files Non-compliant requirements: Enable Nullable Reference Types in .csproj and bazel files Requires further human verification: Verify that the nullability annotations are correct and prevent null reference exceptions in practice

⏱️ Estimated effort to review: 1 🔵⚪⚪⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Null Assignment The SessionId property is set to null! in Dispose method which could potentially cause issues if the property is accessed after disposal. Consider making the property nullable instead. this.SessionId = null!;

[qodo-merge-pro]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Add nullable annotation to property Initialize SessionId property with a nullable annotation since it can be null. Change the property type to SessionId? to properly reflect nullability. dotnet/src/webdriver/WebDriver.cs [192] -public SessionId SessionId { get; private set; } +public SessionId? SessionId { get; private set; } Apply this suggestion Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies that SessionId should be marked as nullable since it can be set to null (as seen in line 742). This improves type safety and makes the nullability explicit in the API.	Medium
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