Add location to LocalizedString and add logging (#331)

src/Microsoft.Extensions.Localization.Abstractions/LocalizedString.cs

@@ -27,6 +27,18 @@ namespace Microsoft.Extensions.Localization
         /// <param name="value">The actual string.</param>
         /// <param name="resourceNotFound">Whether the string was not found in a resource. Set this to <c>true</c> to indicate an alternate string value was used.</param>
         public LocalizedString(string name, string value, bool resourceNotFound)
+            : this(name, value, resourceNotFound, searchedLocation: null)
+        {
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="LocalizedString"/>.
+        /// </summary>
+        /// <param name="name">The name of the string in the resource it was loaded from.</param>
+        /// <param name="value">The actual string.</param>
+        /// <param name="resourceNotFound">Whether the string was not found in a resource. Set this to <c>true</c> to indicate an alternate string value was used.</param>
+        /// <param name="searchedLocation">The location which was searched for a localization value.</param>
+        public LocalizedString(string name, string value, bool resourceNotFound, string searchedLocation)
         {
             if (name == null)
             {
@@ -41,6 +53,7 @@ namespace Microsoft.Extensions.Localization
             Name = name;
             Value = value;
             ResourceNotFound = resourceNotFound;
+            SearchedLocation = searchedLocation;
         }
 
         public static implicit operator string(LocalizedString localizedString)
@@ -63,6 +76,11 @@ namespace Microsoft.Extensions.Localization
         /// </summary>
         public bool ResourceNotFound { get; }
 
+        /// <summary>
+        /// The location which was searched for a localization value.
+        /// </summary>
+        public string SearchedLocation { get; }
+
         /// <summary>
         /// Returns the actual string.
         /// </summary>

src/Microsoft.Extensions.Localization/Internal/ResourceManagerStringLocalizerLoggerExtensions.cs

@@ -0,0 +1,27 @@
+// 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.Globalization;
+using Microsoft.Extensions.Logging;
+
+namespace Microsoft.Extensions.Localization.Internal
+{
+    internal static class ResourceManagerStringLocalizerLoggerExtensions
+    {
+        private static readonly Action<ILogger, string, string, CultureInfo, Exception> _searchedLocation;
+
+        static ResourceManagerStringLocalizerLoggerExtensions()
+        {
+            _searchedLocation = LoggerMessage.Define<string, string, CultureInfo>(
+                LogLevel.Debug,
+                1,
+                $"{nameof(ResourceManagerStringLocalizer)} searched for '{{Key}}' in '{{LocationSearched}}' with culture '{{Culture}}'.");
+        }
+
+        public static void SearchedLocation(this ILogger logger, string key, string searchedLocation, CultureInfo culture)
+        {
+            _searchedLocation(logger, key, searchedLocation, culture, null);
+        }
+    }
+}

src/Microsoft.Extensions.Localization/Microsoft.Extensions.Localization.csproj

@@ -15,6 +15,7 @@
     <ProjectReference Include="..\Microsoft.Extensions.Localization.Abstractions\Microsoft.Extensions.Localization.Abstractions.csproj" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="1.2.0-*" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="1.2.0-*" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' ">

src/Microsoft.Extensions.Localization/ResourceManagerStringLocalizer.cs

@@ -8,6 +8,7 @@ using System.Globalization;
 using System.Reflection;
 using System.Resources;
 using Microsoft.Extensions.Localization.Internal;
+using Microsoft.Extensions.Logging;
 
 namespace Microsoft.Extensions.Localization
 {
@@ -23,6 +24,7 @@ namespace Microsoft.Extensions.Localization
         private readonly ResourceManager _resourceManager;
         private readonly IResourceStringProvider _resourceStringProvider;
         private readonly string _resourceBaseName;
+        private readonly ILogger _logger;
 
         /// <summary>
         /// Creates a new <see cref="ResourceManagerStringLocalizer"/>.
@@ -31,16 +33,19 @@ namespace Microsoft.Extensions.Localization
         /// <param name="resourceAssembly">The <see cref="Assembly"/> that contains the strings as embedded resources.</param>
         /// <param name="baseName">The base name of the embedded resource that contains the strings.</param>
         /// <param name="resourceNamesCache">Cache of the list of strings for a given resource assembly name.</param>
+        /// <param name="logger">The <see cref="ILogger"/>.</param>
         public ResourceManagerStringLocalizer(
             ResourceManager resourceManager,
             Assembly resourceAssembly,
             string baseName,
-            IResourceNamesCache resourceNamesCache)
+            IResourceNamesCache resourceNamesCache,
+            ILogger logger)
             : this(
                 resourceManager,
                 new AssemblyWrapper(resourceAssembly),
                 baseName,
-                resourceNamesCache)
+                resourceNamesCache,
+                logger)
         {
         }
 
@@ -51,12 +56,14 @@ namespace Microsoft.Extensions.Localization
             ResourceManager resourceManager,
             AssemblyWrapper resourceAssemblyWrapper,
             string baseName,
-            IResourceNamesCache resourceNamesCache)
+            IResourceNamesCache resourceNamesCache,
+            ILogger logger)
             : this(
                   resourceManager,
                   new AssemblyResourceStringProvider(resourceNamesCache, resourceAssemblyWrapper, baseName),
                   baseName,
-                  resourceNamesCache)
+                  resourceNamesCache,
+                  logger)
         {
         }
 
@@ -67,7 +74,8 @@ namespace Microsoft.Extensions.Localization
             ResourceManager resourceManager,
             IResourceStringProvider resourceStringProvider,
             string baseName,
-            IResourceNamesCache resourceNamesCache)
+            IResourceNamesCache resourceNamesCache,
+            ILogger logger)
         {
             if (resourceManager == null)
             {
@@ -89,10 +97,16 @@ namespace Microsoft.Extensions.Localization
                 throw new ArgumentNullException(nameof(resourceNamesCache));
             }
 
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
             _resourceStringProvider = resourceStringProvider;
             _resourceManager = resourceManager;
             _resourceBaseName = baseName;
             _resourceNamesCache = resourceNamesCache;
+            _logger = logger;
         }
 
         /// <inheritdoc />
@@ -107,7 +121,7 @@ namespace Microsoft.Extensions.Localization
 
                 var value = GetStringSafely(name, null);
 
-                return new LocalizedString(name, value ?? name, resourceNotFound: value == null);
+                return new LocalizedString(name, value ?? name, resourceNotFound: value == null, searchedLocation: _resourceBaseName);
             }
         }
 
@@ -124,7 +138,7 @@ namespace Microsoft.Extensions.Localization
                 var format = GetStringSafely(name, null);
                 var value = string.Format(format ?? name, arguments);
 
-                return new LocalizedString(name, value, resourceNotFound: format == null);
+                return new LocalizedString(name, value, resourceNotFound: format == null, searchedLocation: _resourceBaseName);
             }
         }
 
@@ -140,13 +154,15 @@ namespace Microsoft.Extensions.Localization
                     _resourceManager,
                     _resourceStringProvider,
                     _resourceBaseName,
-                    _resourceNamesCache)
+                    _resourceNamesCache,
+                    _logger)
                 : new ResourceManagerWithCultureStringLocalizer(
                     _resourceManager,
                     _resourceStringProvider,
                     _resourceBaseName,
                     _resourceNamesCache,
-                    culture);
+                    culture,
+                    _logger);
         }
 
         /// <inheritdoc />
@@ -173,7 +189,7 @@ namespace Microsoft.Extensions.Localization
             foreach (var name in resourceNames)
             {
                 var value = GetStringSafely(name, culture);
-                yield return new LocalizedString(name, value ?? name, resourceNotFound: value == null);
+                yield return new LocalizedString(name, value ?? name, resourceNotFound: value == null, searchedLocation: _resourceBaseName);
             }
         }
 
@@ -191,7 +207,11 @@ namespace Microsoft.Extensions.Localization
                 throw new ArgumentNullException(nameof(name));
             }
 
-            var cacheKey = $"name={name}&culture={(culture ?? CultureInfo.CurrentUICulture).Name}";
+            var keyCulture = culture ?? CultureInfo.CurrentUICulture;
+
+            var cacheKey = $"name={name}&culture={keyCulture.Name}";
+
+            _logger.SearchedLocation(name, _resourceBaseName, keyCulture);
 
             if (_missingManifestCache.ContainsKey(cacheKey))
             {

src/Microsoft.Extensions.Localization/ResourceManagerStringLocalizerFactory.cs

@@ -6,6 +6,7 @@ using System.Collections.Concurrent;
 using System.IO;
 using System.Reflection;
 using System.Resources;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
 namespace Microsoft.Extensions.Localization
@@ -24,20 +25,30 @@ namespace Microsoft.Extensions.Localization
         private readonly ConcurrentDictionary<string, ResourceManagerStringLocalizer> _localizerCache =
             new ConcurrentDictionary<string, ResourceManagerStringLocalizer>();
         private readonly string _resourcesRelativePath;
+        private readonly ILoggerFactory _loggerFactory;
 
         /// <summary>
         /// Creates a new <see cref="ResourceManagerStringLocalizer"/>.
         /// </summary>
         /// <param name="localizationOptions">The <see cref="IOptions{LocalizationOptions}"/>.</param>
+        /// <param name="loggerFactory">The <see cref="ILoggerFactory"/>.</param>
         public ResourceManagerStringLocalizerFactory(
-            IOptions<LocalizationOptions> localizationOptions)
+            IOptions<LocalizationOptions> localizationOptions,
+            ILoggerFactory loggerFactory)
         {
             if (localizationOptions == null)
             {
                 throw new ArgumentNullException(nameof(localizationOptions));
             }
 
+            if (loggerFactory == null)
+            {
+                throw new ArgumentNullException(nameof(loggerFactory));
+            }
+
             _resourcesRelativePath = localizationOptions.Value.ResourcesPath ?? string.Empty;
+            _loggerFactory = loggerFactory;
+
             if (!string.IsNullOrEmpty(_resourcesRelativePath))
             {
                 _resourcesRelativePath = _resourcesRelativePath.Replace(Path.AltDirectorySeparatorChar, '.')
@@ -180,7 +191,8 @@ namespace Microsoft.Extensions.Localization
                 new ResourceManager(baseName, assembly),
                 assembly,
                 baseName,
-                _resourceNamesCache);
+                _resourceNamesCache,
+                _loggerFactory.CreateLogger<ResourceManagerStringLocalizer>());
         }
 
         /// <summary>

src/Microsoft.Extensions.Localization/ResourceManagerWithCultureStringLocalizer.cs

@@ -7,6 +7,7 @@ using System.Globalization;
 using System.Reflection;
 using System.Resources;
 using Microsoft.Extensions.Localization.Internal;
+using Microsoft.Extensions.Logging;
 
 namespace Microsoft.Extensions.Localization
 {
@@ -26,13 +27,15 @@ namespace Microsoft.Extensions.Localization
         /// <param name="baseName">The base name of the embedded resource that contains the strings.</param>
         /// <param name="resourceNamesCache">Cache of the list of strings for a given resource assembly name.</param>
         /// <param name="culture">The specific <see cref="CultureInfo"/> to use.</param>
+        /// <param name="logger">The <see cref="ILogger"/>.</param>
         internal ResourceManagerWithCultureStringLocalizer(
             ResourceManager resourceManager,
             IResourceStringProvider resourceStringProvider,
             string baseName,
             IResourceNamesCache resourceNamesCache,
-            CultureInfo culture)
+            CultureInfo culture,
-            : base(resourceManager, resourceStringProvider, baseName, resourceNamesCache)
+            ILogger logger)
+            : base(resourceManager, resourceStringProvider, baseName, resourceNamesCache, logger)
         {
             if (resourceManager == null)
             {
@@ -70,13 +73,15 @@ namespace Microsoft.Extensions.Localization
         /// <param name="baseName">The base name of the embedded resource that contains the strings.</param>
         /// <param name="resourceNamesCache">Cache of the list of strings for a given resource assembly name.</param>
         /// <param name="culture">The specific <see cref="CultureInfo"/> to use.</param>
+        /// <param name="logger">The <see cref="ILogger"/>.</param>
         public ResourceManagerWithCultureStringLocalizer(
             ResourceManager resourceManager,
             Assembly resourceAssembly,
             string baseName,
             IResourceNamesCache resourceNamesCache,
-            CultureInfo culture)
+            CultureInfo culture,
-            : base(resourceManager, resourceAssembly, baseName, resourceNamesCache)
+            ILogger logger)
+            : base(resourceManager, resourceAssembly, baseName, resourceNamesCache, logger)
         {
             if (resourceManager == null)
             {

test/Microsoft.AspNetCore.Localization.Tests/Microsoft.AspNetCore.Localization.Tests.csproj

@@ -10,6 +10,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.AspNetCore.Localization\Microsoft.AspNetCore.Localization.csproj" />
     <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="1.2.0-*" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0-*" />
     <PackageReference Include="xunit" Version="2.2.0-*" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0-*" />

test/Microsoft.Extensions.Localization.Tests/Microsoft.Extensions.Localization.Tests.csproj

@@ -9,7 +9,9 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.Extensions.Localization\Microsoft.Extensions.Localization.csproj" />
+    <PackageReference Include="Microsoft.AspNetCore.Testing" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="1.2.0-*" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Testing" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0-*" />
     <PackageReference Include="Moq" Version="4.6.36-*" />
     <PackageReference Include="xunit" Version="2.2.0-*" />

test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerFactoryTest.cs

@@ -4,6 +4,8 @@
 using System;
 using System.IO;
 using System.Reflection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Testing;
 using Microsoft.Extensions.Options;
 using Moq;
 using Xunit;
@@ -19,8 +21,9 @@ namespace Microsoft.Extensions.Localization.Tests
 
         public TestResourceManagerStringLocalizerFactory(
             IOptions<LocalizationOptions> localizationOptions,
-            ResourceLocationAttribute resourceLocationAttribute)
+            ResourceLocationAttribute resourceLocationAttribute,
-            : base(localizationOptions)
+            ILoggerFactory loggerFactory)
+            : base(localizationOptions, loggerFactory)
         {
             _resourceLocationAttribute = resourceLocationAttribute;
         }
@@ -50,12 +53,15 @@ namespace Microsoft.Extensions.Localization.Tests
             options.Setup(o => o.Value).Returns(locOptions);
 
             var resourceLocationAttribute = new ResourceLocationAttribute(Path.Combine("My", "Resources"));
+            var loggerFactory = NullLoggerFactory.Instance;
             var typeFactory = new TestResourceManagerStringLocalizerFactory(
                 options.Object,
-                resourceLocationAttribute);
+                resourceLocationAttribute,
+                loggerFactory);
             var stringFactory = new TestResourceManagerStringLocalizerFactory(
                 options.Object,
-                resourceLocationAttribute);
+                resourceLocationAttribute,
+                loggerFactory);
             var type = typeof(ResourceManagerStringLocalizerFactoryTest);
             var assemblyName = new AssemblyName(type.GetTypeInfo().Assembly.FullName);
 
@@ -75,7 +81,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
 
             // Act
             var result1 = factory.Create(typeof(ResourceManagerStringLocalizerFactoryTest));
@@ -92,7 +99,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
 
             // Act
             var result1 = factory.Create(typeof(ResourceManagerStringLocalizerFactoryTest));
@@ -110,9 +118,11 @@ namespace Microsoft.Extensions.Localization.Tests
             locOptions.ResourcesPath = Path.Combine("My", "Resources");
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
+            var loggerFactory = NullLoggerFactory.Instance;
             var factory = new TestResourceManagerStringLocalizerFactory(
                 options.Object,
-                resourceLocationAttribute: null);
+                resourceLocationAttribute: null,
+                loggerFactory: loggerFactory);
 
             // Act
             factory.Create(typeof(ResourceManagerStringLocalizerFactoryTest));
@@ -128,7 +138,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
             var location = typeof(ResourceManagerStringLocalizer).GetTypeInfo().Assembly.FullName;
 
             // Act
@@ -146,7 +157,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
             var location = typeof(ResourceManagerStringLocalizer).GetTypeInfo().Assembly.FullName;
 
             // Act
@@ -164,7 +176,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
             var location1 = new AssemblyName(typeof(ResourceManagerStringLocalizer).GetTypeInfo().Assembly.FullName).Name;
             var location2 = new AssemblyName(typeof(ResourceManagerStringLocalizerFactoryTest).GetTypeInfo().Assembly.FullName).Name;
 
@@ -184,9 +197,11 @@ namespace Microsoft.Extensions.Localization.Tests
             locOptions.ResourcesPath = Path.Combine("My", "Resources");
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
+            var loggerFactory = NullLoggerFactory.Instance;
             var factory = new TestResourceManagerStringLocalizerFactory(
                 options.Object,
-                resourceLocationAttribute: null);
+                resourceLocationAttribute: null,
+                loggerFactory: loggerFactory);
 
             // Act
             var result1 = factory.Create("baseName", location: "Microsoft.Extensions.Localization.Tests");
@@ -202,7 +217,8 @@ namespace Microsoft.Extensions.Localization.Tests
             var locOptions = new LocalizationOptions();
             var options = new Mock<IOptions<LocalizationOptions>>();
             options.Setup(o => o.Value).Returns(locOptions);
-            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object);
+            var loggerFactory = NullLoggerFactory.Instance;
+            var factory = new ResourceManagerStringLocalizerFactory(localizationOptions: options.Object, loggerFactory: loggerFactory);
 
             // Act & Assert
             Assert.Throws<ArgumentNullException>(() => factory.Create("baseName", location: null));

test/Microsoft.Extensions.Localization.Tests/ResourceManagerStringLocalizerTest.cs

@@ -1,13 +1,15 @@
 // 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.Globalization;
 using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Resources;
+using Microsoft.AspNetCore.Testing;
 using Microsoft.Extensions.Localization.Internal;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Testing;
 using Xunit;
 
 namespace Microsoft.Extensions.Localization.Tests
@@ -23,14 +25,17 @@ namespace Microsoft.Extensions.Localization.Tests
             var resourceAssembly = new TestAssemblyWrapper();
             var resourceManager = new TestResourceManager(baseName, resourceAssembly.Assembly);
             var resourceStreamManager = new TestResourceStringProvider(resourceNamesCache, resourceAssembly, baseName);
+            var logger = Logger;
             var localizer1 = new ResourceManagerStringLocalizer(resourceManager,
                 resourceStreamManager,
                 baseName,
-                resourceNamesCache);
+                resourceNamesCache,
+                logger);
             var localizer2 = new ResourceManagerStringLocalizer(resourceManager,
                 resourceStreamManager,
                 baseName,
-                resourceNamesCache);
+                resourceNamesCache,
+                logger);
 
             // Act
             for (int i = 0; i < 5; i++)
@@ -56,16 +61,19 @@ namespace Microsoft.Extensions.Localization.Tests
             var resourceManager2 = new TestResourceManager(baseName, resourceAssembly2.Assembly);
             var resourceStreamManager1 = new TestResourceStringProvider(resourceNamesCache, resourceAssembly1, baseName);
             var resourceStreamManager2 = new TestResourceStringProvider(resourceNamesCache, resourceAssembly2, baseName);
+            var logger = Logger;
             var localizer1 = new ResourceManagerStringLocalizer(
                 resourceManager1,
                 resourceStreamManager1,
                 baseName,
-                resourceNamesCache);
+                resourceNamesCache,
+                logger);
             var localizer2 = new ResourceManagerStringLocalizer(
                 resourceManager2,
                 resourceStreamManager2,
                 baseName,
-                resourceNamesCache);
+                resourceNamesCache,
+                logger);
 
             // Act
             localizer1.GetAllStrings().ToList();
@@ -77,6 +85,57 @@ namespace Microsoft.Extensions.Localization.Tests
             Assert.Equal(expectedCallCount, resourceAssembly2.GetManifestResourceStreamCallCount);
         }
 
+        [Fact]
+        public void GetString_PopulatesSearchedLocationOnLocalizedString()
+        {
+            // Arrange
+            var baseName = "Resources.TestResource";
+            var resourceNamesCache = new ResourceNamesCache();
+            var resourceAssembly = new TestAssemblyWrapper();
+            var resourceManager = new TestResourceManager(baseName, resourceAssembly.Assembly);
+            var resourceStreamManager = new TestResourceStringProvider(resourceNamesCache, resourceAssembly, baseName);
+            var logger = Logger;
+            var localizer = new ResourceManagerStringLocalizer(
+                resourceManager,
+                resourceStreamManager,
+                baseName,
+                resourceNamesCache,
+                logger);
+
+            // Act
+            var value = localizer["name"];
+
+            // Assert
+            Assert.Equal("Resources.TestResource", value.SearchedLocation);
+        }
+
+        [Fact]
+        [ReplaceCulture("en-US", "en-US")]
+        public void GetString_LogsLocationSearched()
+        {
+            // Arrange
+            var baseName = "Resources.TestResource";
+            var resourceNamesCache = new ResourceNamesCache();
+            var resourceAssembly = new TestAssemblyWrapper();
+            var resourceManager = new TestResourceManager(baseName, resourceAssembly.Assembly);
+            var resourceStreamManager = new TestResourceStringProvider(resourceNamesCache, resourceAssembly, baseName);
+            var logger = Logger;
+
+            var localizer = new ResourceManagerStringLocalizer(
+                resourceManager,
+                resourceStreamManager,
+                baseName,
+                resourceNamesCache,
+                logger);
+
+            // Act
+            var value = localizer["a key!"];
+
+            // Assert
+            Assert.Equal(1, Sink.Writes.Count);
+            Assert.Equal("ResourceManagerStringLocalizer searched for 'a key!' in 'Resources.TestResource' with culture 'en-US'.", Sink.Writes.First().State.ToString());
+        }
+
         [Theory]
         [InlineData(true)]
         [InlineData(false)]
@@ -88,11 +147,13 @@ namespace Microsoft.Extensions.Localization.Tests
             var resourceAssembly = new TestAssemblyWrapper();
             var resourceManager = new TestResourceManager(baseName, resourceAssembly.Assembly);
             var resourceStreamManager = new TestResourceStringProvider(resourceNamesCache, resourceAssembly, baseName);
+            var logger = Logger;
             var localizer = new ResourceManagerStringLocalizer(
                 resourceManager,
                 resourceStreamManager,
                 baseName,
-                resourceNamesCache);
+                resourceNamesCache,
+                logger);
 
             // Act
             // We have to access the result so it evaluates.
@@ -113,12 +174,15 @@ namespace Microsoft.Extensions.Localization.Tests
             var baseName = "testington";
             var resourceAssembly = new TestAssemblyWrapper("Assembly1");
             var resourceManager = new TestResourceManager(baseName, resourceAssembly.Assembly);
+            var logger = Logger;
+
             var localizer = new ResourceManagerWithCultureStringLocalizer(
                 resourceManager,
                 resourceAssembly.Assembly,
                 baseName,
                 resourceNamesCache,
-                CultureInfo.CurrentCulture);
+                CultureInfo.CurrentCulture,
+                logger);
 
             // Act & Assert
             var exception = Assert.Throws<MissingManifestResourceException>(() =>
@@ -162,6 +226,17 @@ namespace Microsoft.Extensions.Localization.Tests
             return result;
         }
 
+
+        private TestSink Sink { get; } = new TestSink();
+
+        private ILogger Logger
+        {
+            get
+            {
+                return new TestLoggerFactory(Sink, true).CreateLogger<ResourceManagerStringLocalizer>();
+            }
+        }
+
         public class TestResourceManager : ResourceManager
         {
             public TestResourceManager(string baseName, Assembly assembly)