Fix handling of GlobalOptions deserializing to null

news/1917-bugfix.md

@@ -0,0 +1 @@
+Fix handling of GlobalOptions deserializing to null

src/SmiServices/Common/Options/GlobalOptionsFactory.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.IO.Abstractions;
 using YamlDotNet.Serialization;
 
 namespace SmiServices.Common.Options
@@ -28,24 +29,23 @@ public GlobalOptionsFactory(
         /// </summary>
         /// <param name="hostProcessName"></param>
         /// <param name="configFilePath"></param>
+        /// <param name="fileSystem"></param>
         /// <returns></returns>
-        public GlobalOptions Load(string hostProcessName, string configFilePath = "default.yaml")
+        public GlobalOptions Load(string hostProcessName, string configFilePath = "default.yaml", IFileSystem? fileSystem = null)
         {
+            fileSystem ??= new FileSystem();
+
             IDeserializer deserializer = new DeserializerBuilder()
                                     .WithObjectFactory(GetGlobalOption)
                                     .IgnoreUnmatchedProperties()
                                     .Build();
 
-            if (!File.Exists(configFilePath))
+            if (!fileSystem.File.Exists(configFilePath))
                 throw new ArgumentException($"Could not find config file '{configFilePath}'");
 
-            string yamlContents = File.ReadAllText(configFilePath);
-
-            using var sr = new StringReader(yamlContents);
-            var globals = deserializer.Deserialize<GlobalOptions>(sr);
-
-            if (globals.LoggingOptions == null)
-                throw new Exception($"Loaded YAML did not contain a {nameof(globals.LoggingOptions)} key. Did you provide a valid config file?");
+            var yamlContents = fileSystem.File.ReadAllText(configFilePath);
+            var globals = deserializer.Deserialize<GlobalOptions?>(yamlContents)
+                ?? throw new Exception("Did not deserialize a GlobalOptions object from the provided YAML file. Does it contain at least one valid key?");
 
             globals.HostProcessName = hostProcessName;
 
@@ -70,10 +70,11 @@ private GlobalOptions Decorate(GlobalOptions globals)
         /// </summary>
         /// <param name="hostProcessName"></param>
         /// <param name="cliOptions"></param>
+        /// <param name="fileSystem"></param>
         /// <returns></returns>
-        public GlobalOptions Load(string hostProcessName, CliOptions cliOptions)
+        public GlobalOptions Load(string hostProcessName, CliOptions cliOptions, IFileSystem? fileSystem = null)
         {
-            GlobalOptions globalOptions = Load(hostProcessName, cliOptions.YamlFile);
+            GlobalOptions globalOptions = Load(hostProcessName, cliOptions.YamlFile, fileSystem);
 
             // The above Load call does the decoration - don't do it here.
             return globalOptions;

tests/SmiServices.IntegrationTests/Common/OptionsTests.cs

@@ -1,8 +1,7 @@
-
 using NUnit.Framework;
 using SmiServices.Common.Options;
 using System;
-using System.Collections.Generic;
+using System.IO.Abstractions.TestingHelpers;
 
 namespace SmiServices.UnitTests.Common
 {
@@ -84,5 +83,26 @@ public void TestDecorators()
                 Assert.That(g.MongoDatabases.ExtractionStoreOptions!.DatabaseName, Is.EqualTo("FFFFF"));
             });
         }
+
+        [Test]
+        public void GlobalOptionsFactory_Load_EmptyFile_ThrowsWithUsefulMessage()
+        {
+            var fileSystem = new MockFileSystem();
+            fileSystem.File.Create("foo.yaml");
+            var globalOptionsFactory = new GlobalOptionsFactory();
+
+            var exc = Assert.Throws<Exception>(() => globalOptionsFactory.Load(nameof(GlobalOptionsFactory_Load_EmptyFile_ThrowsWithUsefulMessage), "foo.yaml", fileSystem));
+            Assert.That(exc.Message, Is.EqualTo("Did not deserialize a GlobalOptions object from the provided YAML file. Does it contain at least one valid key?"));
+        }
+
+        [Test]
+        public void GlobalOptionsFactory_Load_MissingFile_ThrowsWithUsefulMessage()
+        {
+            var fileSystem = new MockFileSystem();
+            var globalOptionsFactory = new GlobalOptionsFactory();
+
+            var exc = Assert.Throws<ArgumentException>(() => globalOptionsFactory.Load(nameof(GlobalOptionsFactory_Load_EmptyFile_ThrowsWithUsefulMessage), "foo.yaml", fileSystem));
+            Assert.That(exc.Message, Is.EqualTo("Could not find config file 'foo.yaml'"));
+        }
     }
 }