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Merged
merged 13 commits into from
Jun 26, 2025
Merged

Add support for application-specific settings files in Host defaults #116987

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5c02142
Initial plan
Copilot Jun 24, 2025
aefc91a
Implement application-specific settings file loading feature
Copilot Jun 24, 2025
95052e4
Merge branch 'main' into copilot/fix-114302
DamianEdwards Jun 25, 2025
6cf47ff
Merge branch 'main' into copilot/fix-114302
DamianEdwards Jun 25, 2025
41607a4
Use TempDirectory class for test file management instead of manual cl…
Copilot Jun 25, 2025
bbcac03
Merge branch 'main' into copilot/fix-114302
DamianEdwards Jun 25, 2025
5fd2080
Merge branch 'main' into copilot/fix-114302
DamianEdwards Jun 25, 2025
1fb1a6d
Add test for application-specific settings with Development environment
Copilot Jun 25, 2025
6295d9b
Fix test to verify Production file is not loaded in Development envir…
Copilot Jun 25, 2025
62b595c
Fix assembly loading to use sanitized application name for valid asse…
Copilot Jun 25, 2025
10e8ee2
Fix assembly loading and enhance test to verify ApplicationName prese…
Copilot Jun 25, 2025
79f3ba2
Use original ApplicationName for Assembly.Load and rename variable fo…
Copilot Jun 25, 2025
d319c1c
Remove FileLoadException catch block from user secrets loading to pre…
Copilot Jun 25, 2025
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2 changes: 2 additions & 0 deletions src/libraries/Microsoft.Extensions.Hosting/src/HostApplicationBuilder.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,7 @@ public sealed class HostApplicationBuilder : IHostApplicationBuilder
/// <item><description>load host <see cref="IConfiguration"/> from "DOTNET_" prefixed environment variables</description></item>
/// <item><description>load host <see cref="IConfiguration"/> from supplied command line args</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from 'appsettings.json' and 'appsettings.[<see cref="IHostEnvironment.EnvironmentName"/>].json'</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from '[<see cref="IHostEnvironment.ApplicationName"/>].settings.json' and '[<see cref="IHostEnvironment.ApplicationName"/>].settings.[<see cref="IHostEnvironment.EnvironmentName"/>].json' when <see cref="IHostEnvironment.ApplicationName"/> is not empty</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from User Secrets when <see cref="IHostEnvironment.EnvironmentName"/> is 'Development' using the entry assembly</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from environment variables</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from supplied command line args</description></item>
Expand All @@ -64,6 +65,7 @@ public HostApplicationBuilder()
/// <item><description>load host <see cref="IConfiguration"/> from "DOTNET_" prefixed environment variables</description></item>
/// <item><description>load host <see cref="IConfiguration"/> from supplied command line args</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from 'appsettings.json' and 'appsettings.[<see cref="IHostEnvironment.EnvironmentName"/>].json'</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from '[<see cref="IHostEnvironment.ApplicationName"/>].settings.json' and '[<see cref="IHostEnvironment.ApplicationName"/>].settings.[<see cref="IHostEnvironment.EnvironmentName"/>].json' when <see cref="IHostEnvironment.ApplicationName"/> is not empty</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from User Secrets when <see cref="IHostEnvironment.EnvironmentName"/> is 'Development' using the entry assembly</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from environment variables</description></item>
/// <item><description>load app <see cref="IConfiguration"/> from supplied command line args</description></item>
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9 changes: 9 additions & 0 deletions src/libraries/Microsoft.Extensions.Hosting/src/HostingHostBuilderExtensions.cs
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Expand Up @@ -182,6 +182,7 @@ public static IHostBuilder ConfigureContainer<TContainerBuilder>(this IHostBuild
/// * load host <see cref="IConfiguration"/> from "DOTNET_" prefixed environment variables
/// * load host <see cref="IConfiguration"/> from supplied command line args
/// * load app <see cref="IConfiguration"/> from 'appsettings.json' and 'appsettings.[<see cref="IHostEnvironment.EnvironmentName"/>].json'
/// * load app <see cref="IConfiguration"/> from '[<see cref="IHostEnvironment.ApplicationName"/>].settings.json' and '[<see cref="IHostEnvironment.ApplicationName"/>].settings.[<see cref="IHostEnvironment.EnvironmentName"/>].json' when <see cref="IHostEnvironment.ApplicationName"/> is not empty
/// * load app <see cref="IConfiguration"/> from User Secrets when <see cref="IHostEnvironment.EnvironmentName"/> is 'Development' using the entry assembly
/// * load app <see cref="IConfiguration"/> from environment variables
/// * load app <see cref="IConfiguration"/> from supplied command line args
Expand Down Expand Up @@ -241,6 +242,14 @@ internal static void ApplyDefaultAppConfiguration(HostBuilderContext hostingCont
appConfigBuilder.AddJsonFile("appsettings.json", optional: true, reloadOnChange: reloadOnChange)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: reloadOnChange);

if (env.ApplicationName is { Length: > 0 })
{
string applicationName = env.ApplicationName.Replace(Path.DirectorySeparatorChar, '_')
.Replace(Path.AltDirectorySeparatorChar, '_');
appConfigBuilder.AddJsonFile($"{applicationName}.settings.json", optional: true, reloadOnChange: reloadOnChange)
.AddJsonFile($"{applicationName}.settings.{env.EnvironmentName}.json", optional: true, reloadOnChange: reloadOnChange);
}

if (env.IsDevelopment() && env.ApplicationName is { Length: > 0 })
{
try
Expand Down
157 changes: 157 additions & 0 deletions src/libraries/Microsoft.Extensions.Hosting/tests/UnitTests/HostBuilderTests.cs
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Expand Up @@ -826,6 +826,163 @@ private class ServiceC
public ServiceC(ServiceD serviceD) { }
}

[Fact]
public void ConfigureDefaults_LoadsApplicationSpecificSettings()
{
string tempPath = Path.GetTempPath();
string appSettingsPath = Path.Combine(tempPath, "testapp.settings.json");
string appSettingsEnvPath = Path.Combine(tempPath, "testapp.settings.Production.json");

try
{
// Create test configuration files
File.WriteAllText(appSettingsPath, """{"TestKey": "AppValue"}""");
File.WriteAllText(appSettingsEnvPath, """{"TestKey": "AppEnvValue", "EnvKey": "EnvValue"}""");

using var host = new HostBuilder()
.ConfigureDefaults(args: null)
.UseContentRoot(tempPath)
.ConfigureHostConfiguration(config =>
{
config.AddInMemoryCollection(new[]
{
new KeyValuePair<string, string>(HostDefaults.ApplicationKey, "testapp"),
new KeyValuePair<string, string>(HostDefaults.EnvironmentKey, "Production")
});
})
.Build();

var configuration = host.Services.GetRequiredService<IConfiguration>();

// Verify that app-specific environment settings override app-specific settings
Assert.Equal("AppEnvValue", configuration["TestKey"]);
Assert.Equal("EnvValue", configuration["EnvKey"]);
}
finally
{
// Clean up test files
File.Delete(appSettingsPath);
File.Delete(appSettingsEnvPath);
}
}

[Fact]
public void ConfigureDefaults_DoesNotLoadApplicationSpecificSettings_WhenApplicationNameIsEmpty()
{
string tempPath = Path.GetTempPath();
string appSettingsPath = Path.Combine(tempPath, ".settings.json");

try
{
// Create test configuration file that should NOT be loaded
File.WriteAllText(appSettingsPath, """{"TestKey": "ShouldNotBeLoaded"}""");

using var host = new HostBuilder()
.ConfigureDefaults(args: null)
.UseContentRoot(tempPath)
.ConfigureHostConfiguration(config =>
{
config.AddInMemoryCollection(new[]
{
new KeyValuePair<string, string>(HostDefaults.ApplicationKey, ""),
new KeyValuePair<string, string>(HostDefaults.EnvironmentKey, "Production")
});
})
.Build();

var configuration = host.Services.GetRequiredService<IConfiguration>();

// Verify that app-specific settings are not loaded when ApplicationName is empty
Assert.Null(configuration["TestKey"]);
}
finally
{
// Clean up test files
if (File.Exists(appSettingsPath))
File.Delete(appSettingsPath);
}
}

[Fact]
public void ConfigureDefaults_ReplacesPathSeparatorsInApplicationName()
{
string tempPath = Path.GetTempPath();
string appSettingsPath = Path.Combine(tempPath, "my_app.settings.json");

try
{
// Create test configuration file with path separators replaced by underscores
File.WriteAllText(appSettingsPath, """{"TestKey": "PathSeparatorValue"}""");

using var host = new HostBuilder()
.ConfigureDefaults(args: null)
.UseContentRoot(tempPath)
.ConfigureHostConfiguration(config =>
{
config.AddInMemoryCollection(new[]
{
new KeyValuePair<string, string>(HostDefaults.ApplicationKey, "my/app"),
new KeyValuePair<string, string>(HostDefaults.EnvironmentKey, "Development")
});
})
.Build();

var configuration = host.Services.GetRequiredService<IConfiguration>();

// Verify that path separators are replaced with underscores
Assert.Equal("PathSeparatorValue", configuration["TestKey"]);
}
finally
{
// Clean up test files
if (File.Exists(appSettingsPath))
File.Delete(appSettingsPath);
}
}

[Fact]
public void ConfigureDefaults_ApplicationSpecificSettingsOverrideAppSettings()
{
string tempPath = Path.GetTempPath();
string appSettingsPath = Path.Combine(tempPath, "appsettings.json");
string appSpecificSettingsPath = Path.Combine(tempPath, "myapp.settings.json");

try
{
// Create test configuration files
File.WriteAllText(appSettingsPath, """{"SharedKey": "AppSettingsValue", "AppKey": "AppSettingsOnly"}""");
File.WriteAllText(appSpecificSettingsPath, """{"SharedKey": "AppSpecificValue", "SpecificKey": "AppSpecificOnly"}""");

using var host = new HostBuilder()
.ConfigureDefaults(args: null)
.UseContentRoot(tempPath)
.ConfigureHostConfiguration(config =>
{
config.AddInMemoryCollection(new[]
{
new KeyValuePair<string, string>(HostDefaults.ApplicationKey, "myapp"),
new KeyValuePair<string, string>(HostDefaults.EnvironmentKey, "Development")
});
})
.Build();

var configuration = host.Services.GetRequiredService<IConfiguration>();

// Verify that app-specific settings override general appsettings
Assert.Equal("AppSpecificValue", configuration["SharedKey"]);
Assert.Equal("AppSettingsOnly", configuration["AppKey"]);
Assert.Equal("AppSpecificOnly", configuration["SpecificKey"]);
}
finally
{
// Clean up test files
if (File.Exists(appSettingsPath))
File.Delete(appSettingsPath);
if (File.Exists(appSpecificSettingsPath))
File.Delete(appSpecificSettingsPath);
}
}

internal class ServiceD { }

internal class ServiceA { }
Expand Down
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