fix(external-system-gateway): resolve ExternalSystemGateway-011 — name-keyed repository lookups replace fetch-all-then-filter on the call hot path

tests/ScadaLink.SiteRuntime.Tests/Repositories/SiteRepositoryTests.cs

@@ -84,6 +84,101 @@ public class SiteRepositoryTests : IDisposable
         Assert.Equal("StableSystem", found.Name);
     }
 
+    // ── ExternalSystemGateway-011: name-keyed repository lookups ──
+
+    /// <summary>
+    /// ExternalSystemGateway-011: the site repository's name-keyed external-system
+    /// lookup returns the matching row, and the same synthetic ID as the by-ID path.
+    /// </summary>
+    [Fact]
+    public async Task ExternalSystemRepository_GetByName_ReturnsMatchingDefinition()
+    {
+        var storage = NewStorage();
+        await storage.InitializeAsync();
+        await storage.StoreExternalSystemAsync(
+            "Alpha", "https://alpha.test", "ApiKey", "{\"key\":\"x\"}", null);
+        await storage.StoreExternalSystemAsync(
+            "Beta", "https://beta.test", "Basic", null, null);
+
+        var repo = new SiteExternalSystemRepository(storage);
+
+        var found = await repo.GetExternalSystemByNameAsync("Beta");
+        Assert.NotNull(found);
+        Assert.Equal("Beta", found!.Name);
+        Assert.Equal("https://beta.test", found.EndpointUrl);
+
+        // The by-name path must produce the same synthetic ID as the by-id path.
+        var byId = await repo.GetExternalSystemByIdAsync(found.Id);
+        Assert.NotNull(byId);
+        Assert.Equal("Beta", byId!.Name);
+    }
+
+    /// <summary>
+    /// ExternalSystemGateway-011: a missing name resolves to <c>null</c>.
+    /// </summary>
+    [Fact]
+    public async Task ExternalSystemRepository_GetByName_MissingName_ReturnsNull()
+    {
+        var storage = NewStorage();
+        await storage.InitializeAsync();
+        await storage.StoreExternalSystemAsync(
+            "Alpha", "https://alpha.test", "ApiKey", null, null);
+
+        var repo = new SiteExternalSystemRepository(storage);
+
+        Assert.Null(await repo.GetExternalSystemByNameAsync("DoesNotExist"));
+    }
+
+    /// <summary>
+    /// ExternalSystemGateway-011: the site repository's name-keyed method lookup
+    /// returns the method scoped to its parent system, or <c>null</c> for a miss.
+    /// </summary>
+    [Fact]
+    public async Task ExternalSystemRepository_GetMethodByName_ResolvesScopedToSystem()
+    {
+        var storage = NewStorage();
+        await storage.InitializeAsync();
+        var methodDefs = "[{\"Name\":\"getData\",\"HttpMethod\":\"GET\",\"Path\":\"/data\"}]";
+        await storage.StoreExternalSystemAsync(
+            "WeatherApi", "https://api.example.com", "ApiKey", null, methodDefs);
+
+        var repo = new SiteExternalSystemRepository(storage);
+        var system = await repo.GetExternalSystemByNameAsync("WeatherApi");
+        Assert.NotNull(system);
+
+        var method = await repo.GetMethodByNameAsync(system!.Id, "getData");
+        Assert.NotNull(method);
+        Assert.Equal("getData", method!.Name);
+        Assert.Equal("GET", method.HttpMethod);
+
+        Assert.Null(await repo.GetMethodByNameAsync(system.Id, "noSuchMethod"));
+    }
+
+    /// <summary>
+    /// ExternalSystemGateway-011: the site repository's name-keyed database-connection
+    /// lookup returns the matching row, or <c>null</c> for a miss.
+    /// </summary>
+    [Fact]
+    public async Task DatabaseConnectionRepository_GetByName_ReturnsMatchingDefinition()
+    {
+        var storage = NewStorage();
+        await storage.InitializeAsync();
+        await storage.StoreDatabaseConnectionAsync(
+            "Plant", "Server=plant;Database=p;", maxRetries: 3, retryDelay: TimeSpan.FromSeconds(2));
+        await storage.StoreDatabaseConnectionAsync(
+            "Historian", "Server=hist;Database=h;", maxRetries: 0, retryDelay: TimeSpan.FromSeconds(5));
+
+        var repo = new SiteExternalSystemRepository(storage);
+
+        var found = await repo.GetDatabaseConnectionByNameAsync("Historian");
+        Assert.NotNull(found);
+        Assert.Equal("Historian", found!.Name);
+        Assert.Equal("Server=hist;Database=h;", found.ConnectionString);
+        Assert.Equal(0, found.MaxRetries);
+
+        Assert.Null(await repo.GetDatabaseConnectionByNameAsync("DoesNotExist"));
+    }
+
     /// <summary>
     /// SiteRuntime-007: the same stability guarantee for notification lists.
     /// </summary>