Add the doc_shots documentation screenshot suite; mod documentation

test_suites/doc_shots/src/DocShotsTestInitializer.cs

@@ -0,0 +1,41 @@
+using System.Linq;
+using Cthangover.Core.Mods;
+using Cthangover.Core.Utils;
+using Godot;
+
+namespace Cthangover.Mods.Dialog.DocShots
+{
+    /// <summary>
+    /// Entry point of the doc_shots suite: adds the driver when the exact flag
+    /// <c>--itest=doc_shots</c> is given. <c>--doc-steps=&lt;file&gt;</c> is the
+    /// steps file, <c>--shots=&lt;dir&gt;</c> where the pictures go.
+    /// </summary>
+    public class DocShotsTestInitializer : IModInitializer
+    {
+        private static bool driverQueued;
+
+        /// <summary>Nothing per mod.</summary>
+        public void OnModLoaded(string modId)
+        {
+        }
+
+        /// <summary>Queues the driver once.</summary>
+        public void OnModResourcesReady()
+        {
+            var args = OS.GetCmdlineUserArgs();
+            if (driverQueued || !args.Any(a => a == "--itest=doc_shots"))
+                return;
+
+            driverQueued = true;
+            var steps = ArgValue(args, "--doc-steps=");
+            var shots = ArgValue(args, "--shots=");
+            GameLogger.Log("TEST", $"DocShotsTestInitializer: steps={steps ?? "none"}, shots={shots ?? "off"}");
+            ModRoot.AddDeferred(new DocShotsDriver(steps, shots));
+        }
+
+        private static string ArgValue(string[] args, string prefix) =>
+            args.Where(a => a.StartsWith(prefix, System.StringComparison.Ordinal))
+                .Select(a => a.Substring(prefix.Length))
+                .FirstOrDefault();
+    }
+}