Issue #21: implement worker bootstrap and options

src/MxGateway.Worker.Tests/Bootstrap/MemoryWorkerEnvironment.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+using MxGateway.Worker.Bootstrap;
+
+namespace MxGateway.Worker.Tests.Bootstrap;
+
+internal sealed class MemoryWorkerEnvironment : IWorkerEnvironment
+{
+    private readonly Dictionary<string, string> _values = new();
+    private readonly Exception? _exception;
+
+    public MemoryWorkerEnvironment()
+    {
+    }
+
+    public MemoryWorkerEnvironment(Exception exception)
+    {
+        _exception = exception;
+    }
+
+    public void Set(string name, string value)
+    {
+        _values[name] = value;
+    }
+
+    public string? GetEnvironmentVariable(string name)
+    {
+        if (_exception is not null)
+        {
+            throw _exception;
+        }
+
+        return _values.TryGetValue(name, out string value)
+            ? value
+            : null;
+    }
+}