aspnetcore/src/Configuration.KeyPerFile/test/ConfigurationProviderCommandLineTest.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Extensions.Configuration.Test;
using Microsoft.Extensions.FileProviders;

namespace Microsoft.Extensions.Configuration.KeyPerFile.Test
{
    public class ConfigurationProviderCommandLineTest : ConfigurationProviderTestBase
    {
        protected override (IConfigurationProvider Provider, Action Initializer) LoadThroughProvider(
            TestSection testConfig)
        {
            var testFiles = new List<IFileInfo>();
            SectionToTestFiles(testFiles, "", testConfig);

            var provider = new KeyPerFileConfigurationProvider(
                new KeyPerFileConfigurationSource
                {
                    Optional = true,
                    FileProvider = new TestFileProvider(testFiles.ToArray())
                });

            return (provider, () => { });
        }

        private void SectionToTestFiles(List<IFileInfo> testFiles, string sectionName, TestSection section)
        {
            foreach (var tuple in section.Values.SelectMany(e => e.Value.Expand(e.Key)))
            {
                testFiles.Add(new TestFile(sectionName + tuple.Key, tuple.Value));
            }

            foreach (var tuple in section.Sections)
            {
                SectionToTestFiles(testFiles, sectionName + tuple.Key + "__", tuple.Section);
            }
        }
    }
}