Make SeqCliConfigFilename test-friendlier with pluggable environment

Author: mloskot

src/SeqCli/Config/RuntimeConfigurationLoader.cs

@@ -13,7 +13,9 @@
 // limitations under the License.
 
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 
 namespace SeqCli.Config;
 
@@ -43,8 +45,13 @@ public static SeqCliConfig Load()
     /// </summary>
     public static string SeqCliConfigFilename()
     {
-        var customConfigFilename = Environment.GetEnvironmentVariable("SEQCLI_CONFIG_FILE");
-        if (!string.IsNullOrEmpty(customConfigFilename))
+        var environment = Environment.GetEnvironmentVariables();
+        return SeqCliConfigFilename(environment.Keys.Cast<string>().ToDictionary(k => k, k => (string?)environment[k]));
+    }
+
+    internal static string SeqCliConfigFilename(Dictionary<string, string?> environment)
+    {
+        if (environment.TryGetValue("SEQCLI_CONFIG_FILE", out var customConfigFilename) && !string.IsNullOrEmpty(customConfigFilename))
         {
             return customConfigFilename;
         }

test/SeqCli.Tests/Config/ConfigFileLocationTests.cs

@@ -1,8 +1,7 @@
-using System;
+using System.Collections.Generic;
 using System.IO;
 using SeqCli.Config;
 using Xunit;
-using Xunit.Sdk;
 
 namespace SeqCli.Tests.Config;
 
@@ -17,31 +16,13 @@ public void DefaultConfigFilename()
     }
 
     [Fact]
-    [EnvironmentOverridenConfigFilenameBeforeAfter(SeqCliConfigFile = "MyCustomSeqCli.json")]
     public void EnvironmentOverridenConfigFilename()
     {
-        var configFile = RuntimeConfigurationLoader.SeqCliConfigFilename();
-        var customConfigFile = Path.Combine(Path.GetTempPath(), "MyCustomSeqCli.json");
+        var customConfigFile = Path.GetTempFileName();
+        var environment = new Dictionary<string, string>();
+        environment.Add("SEQCLI_CONFIG_FILE", customConfigFile);
+
+        var configFile = RuntimeConfigurationLoader.SeqCliConfigFilename(environment);
         Assert.Equal(customConfigFile, configFile);
     }
 }
-
-[AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
-public class EnvironmentOverridenConfigFilenameBeforeAfter : BeforeAfterTestAttribute
-{
-    private string originalValue;
-    public string SeqCliConfigFile { get; set; }
-
-    public override void Before(System.Reflection.MethodInfo methodUnderTest)
-    {
-        originalValue = Environment.GetEnvironmentVariable("SEQCLI_CONFIG_FILE");
-
-        var configFile = Path.Combine(Path.GetTempPath(), SeqCliConfigFile);
-        Environment.SetEnvironmentVariable("SEQCLI_CONFIG_FILE", configFile);
-    }
-
-    public override void After(System.Reflection.MethodInfo methodUnderTest)
-    {
-        Environment.SetEnvironmentVariable("SEQCLI_CONFIG_FILE", originalValue);
-    }
-}