Add uri replacement handler (#158)

* Add uri replacement handler

* Bump minor version

* Add changelog entry.

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.3.0] - 2023-11-02
+
+### Added
+
+- Added uri replacement handler.
+
 ## [1.2.0] - 2023-10-23
 
 ### Added

Microsoft.Kiota.Http.HttpClientLibrary.Tests/Middleware/UriReplacementHandlerTests.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.Kiota.Http.HttpClientLibrary.Middleware;
+using Microsoft.Kiota.Http.HttpClientLibrary.Middleware.Options;
+using Moq;
+using Xunit;
+
+namespace Microsoft.Kiota.Http.HttpClientLibrary.Tests.Middleware;
+
+public class UriReplacementOptionTests {
+    [Fact]
+    public void Does_Nothing_When_Url_Replacement_Is_Disabled()
+    {
+        var uri = new Uri("http://localhost/test");
+        var disabled = new UriReplacementHandlerOption(false, new Dictionary<string, string>());
+
+        Assert.False(disabled.IsEnabled());
+        Assert.Equal(uri, disabled.Replace(uri));
+
+        disabled = new UriReplacementHandlerOption(false, new Dictionary<string, string>{
+            {"test", ""}
+        });
+
+        Assert.Equal(uri, disabled.Replace(uri));
+    }
+
+    [Fact]
+    public void Returns_Null_When_Url_Provided_Is_Null()
+    {
+        var disabled = new UriReplacementHandlerOption(false, new Dictionary<string, string>());
+
+        Assert.False(disabled.IsEnabled());
+        Assert.Null(disabled.Replace(null));
+    }
+
+    [Fact]
+    public void Replaces_Key_In_Path_With_Value()
+    {
+        var uri = new Uri("http://localhost/test");
+        var option = new UriReplacementHandlerOption(true, new Dictionary<string, string>{{"test", ""}});
+
+        Assert.True(option.IsEnabled());
+        Assert.Equal("http://localhost/", option.Replace(uri)!.ToString());
+    }
+}
+
+public class UriReplacementHandlerTests
+{
+    [Fact]
+    public async Task Calls_Uri_ReplacementAsync()
+    {
+        var mockReplacement = new Mock<IUriReplacementHandlerOption>();
+        mockReplacement.Setup(static x => x.IsEnabled()).Returns(true);
+        mockReplacement.Setup(static x => x.Replace(It.IsAny<Uri>())).Returns(new Uri("http://changed"));
+
+        var handler = new UriReplacementHandler<IUriReplacementHandlerOption>(mockReplacement.Object)
+        {
+            InnerHandler = new FakeSuccessHandler()
+        };
+        var msg = new HttpRequestMessage(HttpMethod.Get, "http://localhost");
+        var client = new HttpClient(handler);
+        await client.SendAsync(msg);
+
+        mockReplacement.Verify(static x=> x.Replace(It.IsAny<Uri>()), Times.Once());
+    }
+}

src/Microsoft.Kiota.Http.HttpClientLibrary.csproj

@@ -14,7 +14,7 @@
     <PackageProjectUrl>https://aka.ms/kiota/docs</PackageProjectUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
     <Deterministic>true</Deterministic>
-    <VersionPrefix>1.2.0</VersionPrefix>
+    <VersionPrefix>1.3.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <!-- Enable this line once we go live to prevent breaking changes -->

src/Middleware/Options/UriReplacementHandlerOption.cs

@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Kiota.Abstractions;
+
+namespace Microsoft.Kiota.Http.HttpClientLibrary.Middleware.Options;
+
+/// <summary>
+/// Interface for making URI replacements.
+/// </summary>
+public interface IUriReplacementHandlerOption : IRequestOption
+{
+    /// <summary>
+    /// Check if URI replacement is enabled for the option.
+    /// </summary>
+    /// <returns>true if replacement is enabled or false otherwise.</returns>
+    bool IsEnabled();
+
+    /// <summary>
+    /// Accepts a URI and returns a new URI with all replacements applied.
+    /// </summary>
+    /// <param name="original">The URI to apply replacements to</param>
+    /// <returns>A new URI with all replacements applied.</returns>
+    Uri? Replace(Uri? original);
+}
+
+/// <summary>
+/// Url replacement options.
+/// </summary>
+public class UriReplacementHandlerOption : IUriReplacementHandlerOption
+{
+    private readonly bool isEnabled;
+
+    private readonly IEnumerable<KeyValuePair<string, string>> replacementPairs;
+
+    /// <summary>
+    /// Creates a new instance of UriReplacementOption.
+    /// </summary>
+    /// <param name="isEnabled">Whether replacement is enabled.</param>
+    /// <param name="replacementPairs">Replacements with the key being a string to match against and the value being the replacement.</param>
+    public UriReplacementHandlerOption(bool isEnabled, IEnumerable<KeyValuePair<string, string>> replacementPairs)
+    {
+        this.isEnabled = isEnabled;
+        this.replacementPairs = replacementPairs;
+    }
+
+    /// <inheritdoc/>
+    public bool IsEnabled()
+    {
+        return isEnabled;
+    }
+
+    /// <inheritdoc/>
+    public Uri? Replace(Uri? original)
+    {
+        if(original is null) return null;
+
+        if(!isEnabled)
+        {
+            return original;
+        }
+
+        var newUrl = new UriBuilder(original);
+        foreach(var pair in replacementPairs)
+        {
+            newUrl.Path = newUrl.Path.Replace(pair.Key, pair.Value);
+        }
+
+        return newUrl.Uri;
+    }
+}

src/Middleware/UriReplacementHandler.cs

@@ -0,0 +1,56 @@
+using System.Diagnostics;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.Kiota.Abstractions;
+using Microsoft.Kiota.Http.HttpClientLibrary.Extensions;
+using Microsoft.Kiota.Http.HttpClientLibrary.Middleware.Options;
+
+namespace Microsoft.Kiota.Http.HttpClientLibrary.Middleware;
+
+/// <summary>
+/// Replaces a portion of the URL.
+/// </summary>
+/// <typeparam name="TUriReplacementHandlerOption">A type with the rules used to perform a URI replacement.</typeparam>
+public class UriReplacementHandler<TUriReplacementHandlerOption> : DelegatingHandler where TUriReplacementHandlerOption : IUriReplacementHandlerOption
+{
+    private readonly TUriReplacementHandlerOption uriReplacement;
+
+    /// <summary>
+    /// Creates a new UriReplacementHandler.
+    /// </summary>
+    /// <param name="uriReplacement">An object with the URI replacement rules.</param>
+    public UriReplacementHandler(TUriReplacementHandlerOption uriReplacement)
+    {
+        this.uriReplacement = uriReplacement;
+    }
+
+    /// <inheritdoc/>
+    protected override async Task<HttpResponseMessage> SendAsync(
+        HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
+    {
+        ActivitySource? activitySource;
+        Activity? activity;
+        if(request.GetRequestOption<ObservabilityOptions>() is ObservabilityOptions obsOptions)
+        {
+            activitySource = new ActivitySource(obsOptions.TracerInstrumentationName);
+            activity = activitySource.StartActivity($"{nameof(UriReplacementHandler<TUriReplacementHandlerOption>)}_{nameof(SendAsync)}");
+            activity?.SetTag("com.microsoft.kiota.handler.uri_replacement.enable", uriReplacement.IsEnabled());
+        }
+        else
+        {
+            activity = null;
+            activitySource = null;
+        }
+
+        try
+        {
+            request.RequestUri = uriReplacement.Replace(request.RequestUri);
+            return await base.SendAsync(request, cancellationToken);
+        }
+        finally
+        {
+            activity?.Dispose();
+            activitySource?.Dispose();
+        }
+    }
+}