Fix operator precedence bug in ValidateSchemaDocument causing rejection of valid boolean schemas

[Copilot]

The ValidateSchemaDocument method incorrectly rejected valid boolean schemas (true and false) due to operator precedence in the pattern matching expression.

Problem

// Before: parsed as "is (not Object) or False or True"
if (document.ValueKind is not JsonValueKind.Object or JsonValueKind.False or JsonValueKind.True)

This evaluated to true when the schema was False or True, throwing exceptions for valid JSON schemas per the spec.

Changes

• Fixed operator precedence with explicit grouping:

  if (document.ValueKind is not (JsonValueKind.Object or JsonValueKind.False or JsonValueKind.True))

• Added tests using the public TransformSchema API to verify top-level boolean schemas (true, false) are correctly accepted and transformed. The new test TransformJsonSchema_BooleanSchemas_Success validates that:

  • true schemas are converted to empty objects {}
  • false schemas are converted to {"not": true}

Original prompt

AIJsonSchemaCreateOptions contains this code:
internal static void ValidateSchemaDocument(JsonElement document, [CallerArgumentExpression("document")] string? paramName = null)
{
if (document.ValueKind is not JsonValueKind.Object or JsonValueKind.False or JsonValueKind.True)
{
Throw.ArgumentException(paramName ?? "schema", "The schema document must be an object or a boolean value.");
}
}
Those ors look wrong. Should they be and not instead? Please confirm, and if this is a bug, fix the bug and add tests the would have failed before the fix and now pass.

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Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull Request Overview

This PR fixes a critical operator precedence bug in the ValidateSchemaDocument method that was incorrectly rejecting valid boolean JSON schemas (true/false). The issue stemmed from C#'s operator precedence rules incorrectly parsing the validation condition.

Key changes:

• Fixed the validation logic by adding parentheses to correctly express the intended condition
• Added comprehensive test coverage for boolean schema validation using the public TransformSchema API

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Schema.Create.cs	Corrected operator precedence in ValidateSchemaDocument by wrapping the or-pattern in parentheses
test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Utilities/AIJsonUtilitiesTests.cs	Added test to verify boolean schemas (true/false) are correctly accepted and transformed

[eiriktsarpalis]

Ugh.