Add CallerArgumentExpression to IsNull/IsNotNull

[CoryCharlton]

Description

• Add CallerArgumentExpression to IsNull/IsNotNull.

Motivation and Context

Improved failure messages without additional work / tech debt. Prior to this change a set of tests like the following would all show the same error: "Assert.IsNull failed."

var test = new();
Assert.IsNull(test.Condition1);
Assert.IsNull(test.Condition2);
Assert.IsNull(test.Condition3); // Assume this test fails

After adding the CallerArgumentExpressionAttribute the default failure message changes to "Assert.IsNull failed. test.Condition3" and it's clear which test failed.

How Has This Been Tested?

Manually

Screenshots

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue with code or algorithm)
• New feature (non-breaking change which adds functionality to code)
• Breaking change (fix or feature that would cause existing functionality to change)
• Config and build (change in the configuration and build system, has no impact on code or features)
• Dependencies (update dependencies and changes associated, has no impact on code or features)
• Unit Tests (add new Unit Test(s) or improved existing one(s), has no impact on code or features)
• Documentation (changes or updates in the documentation, has no impact on code or features)

Checklist:

• My code follows the code style of this project (only if there are changes in source code).
• My changes require an update to the documentation (there are changes that require the docs website to be updated).
• I have updated the documentation accordingly (the changes require an update on the docs in this repo).
• I have read the CONTRIBUTING document.
• I have tested everything locally and all new and existing tests passed (only if there are changes in source code).
• I have added new tests to cover my changes.

[josesimoes]

LGTM! Thanks

[josesimoes]

@CoryCharlton I've merged this without publishing a new release. Am I right to presume that you'll be adding this to the other asserts in the coming days? At your pace and as time permits, of course. 😅

[CoryCharlton]

@CoryCharlton I've merged this without publishing a new release. Am I right to presume that you'll be adding this to the other asserts in the coming days? At your pace and as time permits, of course. 😅

@josesimoes I will have another PR for the remaining methods. I'll keep it to a single PR with clear, targeted, commits.