Revise IsSpaRoute

Removed `static` from `SpaGetRoutes` and `SpaPostRoutes` because their
modification was lasting between test instantiations.

Author: marksvc

src/SIL.XForge.Scripture/Startup.cs

@@ -55,7 +55,7 @@ public class Startup
     /// <summary>
     /// Routes that should be handled by SPA in both production and development.
     /// </summary>
-    private static readonly HashSet<string> SpaGetRoutes =
+    private readonly HashSet<string> SpaGetRoutes =
     [
         "index.html",
         "prerendered-routes.json",
@@ -90,7 +90,7 @@ public class Startup
 
     private static readonly HashSet<string> DevelopmentSpaPostRoutes = ["sockjs-node"];
     private static readonly HashSet<string> ProductionSpaPostRoutes = [];
-    private static readonly HashSet<string> SpaPostRoutes = [];
+    private readonly HashSet<string> SpaPostRoutes = [];
 
     public Startup(IConfiguration configuration, IWebHostEnvironment env, ILoggerFactory loggerFactory)
     {
@@ -360,15 +360,15 @@ internal bool IsSpaRoute(HttpContext context)
         //   /@vite/client
         // Anything could conceivably contain a '?'.
 
-        // Look at what is after the first slash, and before the next slash or '?'. Match paths like /projects/123456789
+        // Look at what is after starting slashes, and before the next slash or '?'. Match paths like /projects/123456789
         // as "projects", /login?a=b as "login", and /safety-worker.js as "safety-worker.js".
-        string exact = path.Split('/', '?').ElementAtOrDefault(1) ?? "";
+        string exact = path?.TrimStart('/').Split('/', '?').FirstOrDefault() ?? string.Empty;
         if (spaRoutes.Contains(exact))
             return true;
 
         // Then look at what is before the first dash or dot. Match paths like /polyfills-C3D4E5F6.js.map and
         // /polyfills.js as "polyfills".
-        string beginning = exact.Split(['-', '.']).FirstOrDefault();
+        string beginning = exact.Split('-', '.').FirstOrDefault();
         if (spaRoutes.Contains(beginning))
             return true;
 

test/SIL.XForge.Scripture.Tests/StartupTests.cs

@@ -11,15 +11,6 @@
 
 namespace SIL.XForge.Scripture;
 
-/// <summary>
-/// Represents what environment the application is running in.
-/// </summary>
-public enum RunMode
-{
-    Development,
-    Production,
-}
-
 [TestFixture]
 public class StartupTests
 {
@@ -177,10 +168,15 @@ private static void IsSpaRoute_Helper(string path, RunMode[] runModes, bool expe
     [TestCase("/connect-project")]
     [TestCase("/serval-administration")]
     [TestCase("/system-administration")]
+    // Handling '//login' may not be very important but would make sense to handle it as if it was normalized to
+    // '/login'.
+    [TestCase("//login")]
+    [TestCase("//login//")]
+    [TestCase("///login")]
     public void IsSpaRoute_ProductionAndDevelopment_True(string path)
     {
         RunMode[] runModes = [RunMode.Production, RunMode.Development];
-        bool expected = true;
+        const bool expected = true;
         IsSpaRoute_Helper(path, runModes, expected);
     }
 
@@ -195,7 +191,7 @@ public void IsSpaRoute_ProductionAndDevelopment_True(string path)
     public void IsSpaRoute_Development_True(string path)
     {
         RunMode[] runModes = [RunMode.Development];
-        bool expected = true;
+        const bool expected = true;
         IsSpaRoute_Helper(path, runModes, expected);
     }
 
@@ -221,7 +217,9 @@ public void IsSpaRoute_Development_True(string path)
     [TestCase("/??/login")]
     [TestCase("/#login")]
     [TestCase("/#/login")]
-    // It may or may not be possible for the path to be the empty string. If it is, let's have ASP.NET handle it.
+    // It may or may not be possible in practice for the path to be null or empty. If it is, let's have ASP.NET handle
+    // it.
+    [TestCase(null)]
     [TestCase("")]
     // The paths "/", "/Index", and "/Status/Error" are handled by ASP.NET and don't even get to IsSpaRoute. If they did
     // for some reason, we'll have IsSpaRoute return false.
@@ -235,7 +233,7 @@ public void IsSpaRoute_Development_True(string path)
     public void IsSpaRoute_ProductionAndDevelopment_False(string path)
     {
         RunMode[] runModes = [RunMode.Production, RunMode.Development];
-        bool expected = false;
+        const bool expected = false;
         IsSpaRoute_Helper(path, runModes, expected);
     }
 
@@ -244,10 +242,19 @@ public void IsSpaRoute_ProductionAndDevelopment_False(string path)
     public void IsSpaRoute_Development_False(string path)
     {
         RunMode[] runModes = [RunMode.Development];
-        bool expected = false;
+        const bool expected = false;
         IsSpaRoute_Helper(path, runModes, expected);
     }
 
+    /// <summary>
+    /// Represents what environment the application is running in.
+    /// </summary>
+    private enum RunMode
+    {
+        Development,
+        Production,
+    }
+
     private class TestEnvironment
     {
         public TestEnvironment(string? environmentName = null)