[dotnet] Remove JSON serialization from .ToString() methods

[RenderMichael]

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Description

This removes the ToString() method on DriverOptions, ReturnedCapabilities, and RemoteSessionSettings, to avoid heavy and AOT-unsafe JSON serialization.

Offshoot of #14734

Motivation and Context

There is an ongoing effort to make operations AOT-safe. Additionally, this ToString() method is heavy, which can be especially taxing when looking at the debugger display for the instance.

Fixes #14741

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, Tests

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Description

• Simplified the DriverOptions.ToString() method by removing JSON serialization and implementing a custom string representation using StringBuilder.
• Added tests for the ToString() method across different browser options (Chrome, Edge, Firefox, Internet Explorer, Safari) to verify the output format.
• Ensured the output includes browser name, version, and platform for better clarity and AOT safety.

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Changes walkthrough 📝

	Relevant files
Enhancement	DriverOptions.cs Simplify `DriverOptions.ToString()` method for AOT safety dotnet/src/webdriver/DriverOptions.cs Removed JSON serialization from ToString() method. Implemented custom string representation using StringBuilder. Included browser name, version, and platform in the output. +31/-2
Tests	ChromeSpecificTests.cs Add test for ChromeOptions ToString method                              dotnet/test/chrome/ChromeSpecificTests.cs Added test for ChromeOptions.ToString() method. Verified output format for browser and platform. +9/-0      EdgeSpecificTests.cs Add test for EdgeOptions ToString method                                  dotnet/test/edge/EdgeSpecificTests.cs Added test for EdgeOptions.ToString() method. Verified output format for browser and platform. +16/-0    FirefoxDriverTest.cs Add test for FirefoxOptions ToString method                            dotnet/test/firefox/FirefoxDriverTest.cs Added test for FirefoxOptions.ToString() method. Verified output format for browser and platform. +9/-0      IeSpecificTests.cs Add test for InternetExplorerOptions ToString method          dotnet/test/ie/IeSpecificTests.cs Added test for InternetExplorerOptions.ToString() method. Verified output format for browser and platform. +8/-0      SafariSpecificTests.cs Add test for SafariOptions ToString method                              dotnet/test/safari/SafariSpecificTests.cs Added test for SafariOptions.ToString() method. Verified output format for browser and platform. +17/-0

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PR Reviewer Guide 🔍

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

🧪 PR contains tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Null Check The ToString() method should handle the case when both browserName and platformName are null/empty. Currently it would return an empty string without any indication of what the object is. Code Duplication The string concatenation logic with commas and platform info is repeated across multiple places. Consider extracting this into a helper method.

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PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Score
Maintainability	✅ Enable or remove commented test attribute to maintain clean test code Suggestion Impact: The commit removed the commented-out test attribute and the entire test method, aligning with the suggestion to clean up the code by removing unused code. code diff: - //[Test] - public void InternetExplorerOptionsToString() - { - var options = new InternetExplorerOptions(); - - Assert.That(options.ToString(), Is.EqualTo("Browser: internet explorer, Platform: windows")); - } Remove commented-out test attribute to either enable the test or remove unused code dotnet/test/ie/IeSpecificTests.cs [363-364] -//[Test] +[Test] public void InternetExplorerOptionsToString() Apply this suggestion Suggestion importance[1-10]: 7 Why: Commented-out test attributes can lead to confusion and maintenance issues. The test should either be properly enabled or removed to maintain code clarity.	7
Enhancement	Use string interpolation for more concise and readable string formatting Consider using string interpolation for cleaner and more readable string formatting dotnet/src/webdriver/DriverOptions.cs [405-412] -builder.Append("Browser: ").Append(browserName); -builder.Append(' '); -builder.Append(browserVersion); +builder.Append($"Browser: {browserName} {browserVersion}"); Apply this suggestion Suggestion importance[1-10]: 5 Why: String interpolation would make the code more readable and maintainable while reducing the number of StringBuilder operations, though the functional impact is minimal.	5
Performance	Pre-allocate StringBuilder capacity to improve performance by avoiding buffer resizing Initialize StringBuilder with an estimated capacity based on expected string length to avoid buffer resizing dotnet/src/webdriver/DriverOptions.cs [399] -StringBuilder builder = new StringBuilder(); +StringBuilder builder = new StringBuilder(100); Apply this suggestion Suggestion importance[1-10]: 3 Why: While pre-allocating capacity can improve performance by avoiding buffer resizing, the impact is minimal given the small size of the strings being built and infrequent usage of ToString().	3
Best practice	Use null coalescing operator to ensure null safety when handling string values Add null coalescing operator to handle null values for browserName and platformName dotnet/src/webdriver/DriverOptions.cs [402-403] -string browserName = this.BrowserName; +string browserName = this.BrowserName ?? string.Empty; if (!string.IsNullOrEmpty(browserName)) Apply this suggestion Suggestion importance[1-10]: 2 Why: The existing null check using string.IsNullOrEmpty is already sufficient and more comprehensive than using the null coalescing operator alone.	2

💡 Need additional feedback ? start a PR chat

[nvborisenko]

I like that this PR excludes json serialization from .ToString() method. We are cleaning up codebase.

The next question: what we want to see as a string representation of any object? While I was walking through codebase, I don't see strong rule for objects. Yeah, json representation is still showing everything, but in general it is not ideal way to represent any object as a string.

@RenderMichael what if I propose just to remove ToString() in this PR? I propose to search for all .ToString() methods where json is involved, and "deprecate/remove" it (as separate unit of work). Let's initiate a discussion about expected string representation of most used objects in selenium (not sure which way is comfortable, issue in GitHub?).

[RenderMichael]

@nvborisenko I completely agree, the three types with JSON serialization in the ToString() method probably do not need those implementations at all. Since there are only 3, I don’t think we need a separate issue (I can change this PR) unless you think some people might disagree. Nobody should depend on the ToString() results, but maybe we want to he careful.

Should I open a separate issue for discussion?

[RenderMichael]

If we want to be careful and alert users, we can change the ToString to

public string ToString() => $"{base.ToString()}, Use ToCapabilities() for a serializable representation.";

[nvborisenko]

Only 3 types? Then I propose to remove ToString() in this PR, and think of about it in separate PR. Discussion will be happened there, not here. Thank you!

[RenderMichael]

Opened #14741

[nvborisenko]

Let's do it: Remove JSON serialization from all ToString() methods here, why not, I am happy to merge. And then think about how to improve it.

[RenderMichael]

Done! PR is ready for review

[nvborisenko]

From all ToString(), then we can consider #14741 as fixed.

[RenderMichael]

All 3 types are ready. Such a satisfying change

[nvborisenko]

Thank you, while you are adjusting PR's topic/description, I will validate that Appium project doesn't use .ToString() for json representation (I hope so).

[RenderMichael]

Hopefully they are not calling ToString() on any ICapabilities instance, since that could be affected here.

[nvborisenko]

You can help me, they are more friendly for .net: https://github.com/appium/dotnet-client (at least at compilation level)

[RenderMichael]

Luckily they do not. This is the only instance of handling ICapabilities on their side.

[nvborisenko]

Thanks Michael!