OpenApiParameterRules.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license.

namespace Microsoft.OpenApi
{
    /// <summary>
    /// The validation rules for <see cref="OpenApiParameter"/>.
    /// </summary>
    [OpenApiRule]
    public static class OpenApiParameterRules
    {
        /// <summary>
        /// Validate the field is required.
        /// </summary>
        public static ValidationRule<IOpenApiParameter> ParameterRequiredFields =>
            new(nameof(ParameterRequiredFields),
                (context, item) =>
                {
                    // name
                    if (item.Name == null)
                    {
                        context.Enter("name");
                        context.CreateError(nameof(ParameterRequiredFields),
                            string.Format(SRResource.Validation_FieldIsRequired, "name", "parameter"));
                        context.Exit();
                    }

                    // in
                    if (item.In == null)
                    {
                        context.Enter("in");
                        context.CreateError(nameof(ParameterRequiredFields),
                            string.Format(SRResource.Validation_FieldIsRequired, "in", "parameter"));
                        context.Exit();
                    }
                });

        /// <summary>
        /// Validate the "required" field is true when "in" is path.
        /// </summary>
        public static ValidationRule<IOpenApiParameter> RequiredMustBeTrueWhenInIsPath =>
            new(nameof(RequiredMustBeTrueWhenInIsPath),
                (context, item) =>
                {
                    // required
                    if (item.In == ParameterLocation.Path && !item.Required)
                    {
                        context.Enter("required");
                        context.CreateError(
                            nameof(RequiredMustBeTrueWhenInIsPath),
                            "\"required\" must be true when parameter location is \"path\"");
                        context.Exit();
                    }
                });

        /// <summary>
        /// Validate that a path parameter should always appear in the path
        /// </summary>
        public static ValidationRule<IOpenApiParameter> PathParameterShouldBeInThePath =>
            new(nameof(PathParameterShouldBeInThePath),
                (context, parameter) =>
                {
                    if (parameter.In == ParameterLocation.Path &&
                           !(context.PathString.Contains("{" + OpenApiVisitorBase.EncodeJsonPointerSegment(parameter.Name) + "}") || context.PathString.Contains("#/components")))
                    {
                        context.Enter("in");
                        context.CreateError(
                            nameof(PathParameterShouldBeInThePath),
                            $"Declared path parameter \"{parameter.Name}\" needs to be defined as a path parameter at either the path or operation level");
                        context.Exit();
                    }
                });
        // add more rule.
    }
}