Function emitDataAnnotations

scripts/codegen/csharp.ts:414–456

* Emit C# data-annotation attributes for a JSON Schema property. * Returns an array of attribute lines (without trailing newlines).

(schema: JSONSchema7, indent: string, csharpType: string)

 * Returns an array of attribute lines (without trailing newlines).
 */
function emitDataAnnotations(schema: JSONSchema7, indent: string, csharpType: string): string[] {
    const attrs: string[] = [];
    const format = schema.format;

    // [Url] + [StringSyntax(StringSyntaxAttribute.Uri)] for format: "uri"
    if (format === "uri") {
        attrs.push(`${indent}[Url]`);
        attrs.push(`${indent}[StringSyntax(StringSyntaxAttribute.Uri)]`);
    }

    // [StringSyntax(StringSyntaxAttribute.Regex)] and [RegularExpression] for format: "regex"
    if (format === "regex") {
        attrs.push(`${indent}[StringSyntax(StringSyntaxAttribute.Regex)]`);
        if (typeof schema.pattern === "string") {
            attrs.push(`${indent}[RegularExpression("${escapeCSharpStringLiteral(schema.pattern)}")]`);
        }
    }

    // [Base64String] for base64-encoded string properties
    if (format === "byte" || (schema as Record<string, unknown>).contentEncoding === "base64") {
        attrs.push(`${indent}[Base64String]`);
    }

    // [RegularExpression] for pattern constraints on non-regex-format properties
    if (format !== "regex" && typeof schema.pattern === "string") {
        attrs.push(`${indent}[RegularExpression("${escapeCSharpStringLiteral(schema.pattern)}")]`);
    }

    // [MinLength] / [MaxLength] for string constraints
    if (typeof schema.minLength === "number" || typeof schema.maxLength === "number") {
        attrs.push(
            `${indent}[UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "Safe for generated string properties: JSON Schema minLength/maxLength map to string length validation, not reflection over trimmed Count members")]`
        );
    }
    if (typeof schema.minLength === "number") {
        attrs.push(`${indent}[MinLength(${schema.minLength})]`);
    }
    if (typeof schema.maxLength === "number") {
        attrs.push(`${indent}[MaxLength(${schema.maxLength})]`);
    }

    return attrs;
}

/**
 * Returns true when a TimeSpan-typed property needs a [JsonConverter] attribute.