fix(unity): build the Player when no subtarget given

.github/workflows/tests.yml

@@ -119,6 +119,13 @@ jobs:
       # default, so this needs no extra setup.
       - name: Validate platform scripts (dist/platforms)
         run: bash scripts/validate-platform-scripts.sh
+      # Which subtarget the default build script asks Unity for. Handing Unity
+      # StandaloneBuildSubtarget.Default made it reuse the subtarget persisted
+      # in the project's Library, so a cached Library from a Server build
+      # turned later Player builds into Server builds. Compiles the resolver
+      # against Unity stubs with the .NET SDK ubuntu-latest ships.
+      - name: Default build script subtarget tests
+        run: bash scripts/test-build-subtarget.sh
       # Parsing those scripts isn't enough for the licensing steps: what
       # matters is which Unity.Licensing.Client invocation each credential
       # combination produces, and whether the seat is handed back on every

dist/default-build-script/Assets/Editor/UnityBuilderAction/Builder.cs

@@ -62,14 +62,6 @@ public static void BuildProject()
         // Gather values from project
         var scenes = EditorBuildSettings.scenes.Where(scene => scene.enabled).Select(s => s.path).ToArray();
 
-#if UNITY_2021_2_OR_NEWER
-        // Determine subtarget
-        StandaloneBuildSubtarget buildSubtarget;
-        if (!options.TryGetValue("standaloneBuildSubtarget", out var subtargetValue) || !Enum.TryParse(subtargetValue, out buildSubtarget)) {
-          buildSubtarget = default;
-        }
-#endif
-
         var target = (BuildTarget) Enum.Parse(typeof(BuildTarget), options["buildTarget"]);
 
         // Define BuildPlayer Options
@@ -79,7 +71,7 @@ public static void BuildProject()
           target = target,
           options = buildOptions,
 #if UNITY_2021_2_OR_NEWER
-          subtarget = (int) buildSubtarget
+          subtarget = BuildSubtarget.Resolve(target, options)
 #endif
         };
 

dist/default-build-script/Assets/Editor/UnityBuilderAction/Input/BuildSubtarget.cs

@@ -0,0 +1,44 @@
+#if UNITY_2021_2_OR_NEWER
+using System;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+
+namespace UnityBuilderAction.Input
+{
+  // Standalone targets build the Player unless -standaloneBuildSubtarget asks for something else.
+  // Handing Unity StandaloneBuildSubtarget.Default instead would make it reuse the subtarget
+  // persisted in the project's Library, so a Library that once built a Server keeps building
+  // Servers, even on a runner without the Dedicated Server module.
+  public static class BuildSubtarget
+  {
+    public static int Resolve(BuildTarget target, Dictionary<string, string> options)
+    {
+      options.TryGetValue("standaloneBuildSubtarget", out var requested);
+
+      if (BuildPipeline.GetBuildTargetGroup(target) != BuildTargetGroup.Standalone)
+      {
+        if (!string.IsNullOrEmpty(requested))
+        {
+          Debug.LogWarning($"Ignoring standaloneBuildSubtarget \"{requested}\": it only applies to standalone targets, not {target}.");
+        }
+
+        return 0;
+      }
+
+      if (string.IsNullOrEmpty(requested))
+      {
+        return (int) StandaloneBuildSubtarget.Player;
+      }
+
+      if (!Enum.TryParse(requested, true, out StandaloneBuildSubtarget subtarget)
+          || !Enum.IsDefined(typeof(StandaloneBuildSubtarget), subtarget))
+      {
+        throw new ArgumentException($"Unknown standaloneBuildSubtarget \"{requested}\"; expected Player or Server.");
+      }
+
+      return (int) subtarget;
+    }
+  }
+}
+#endif

plugins/unity/dist/unity-builder/dist/default-build-script/Assets/Editor/UnityBuilderAction/Builder.cs

@@ -89,14 +89,6 @@ public static void BuildProject()
         // Gather values from project
         var scenes = EditorBuildSettings.scenes.Where(scene => scene.enabled).Select(s => s.path).ToArray();
 
-#if UNITY_2021_2_OR_NEWER
-        // Determine subtarget
-        StandaloneBuildSubtarget buildSubtarget;
-        if (!options.TryGetValue("standaloneBuildSubtarget", out var subtargetValue) || !Enum.TryParse(subtargetValue, out buildSubtarget)) {
-          buildSubtarget = default;
-        }
-#endif
-
         BuildTarget buildTarget = (BuildTarget) Enum.Parse(typeof(BuildTarget), options["buildTarget"]);
 
         // Define BuildPlayerOptions
@@ -106,7 +98,7 @@ public static void BuildProject()
           target = buildTarget,
           options = buildOptions,
 #if UNITY_2021_2_OR_NEWER
-          subtarget = (int) buildSubtarget
+          subtarget = BuildSubtarget.Resolve(buildTarget, options)
 #endif
         };
 

plugins/unity/dist/unity-builder/dist/default-build-script/Assets/Editor/UnityBuilderAction/Input/BuildSubtarget.cs

@@ -0,0 +1,44 @@
+#if UNITY_2021_2_OR_NEWER
+using System;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+
+namespace UnityBuilderAction.Input
+{
+  // Standalone targets build the Player unless -standaloneBuildSubtarget asks for something else.
+  // Handing Unity StandaloneBuildSubtarget.Default instead would make it reuse the subtarget
+  // persisted in the project's Library, so a Library that once built a Server keeps building
+  // Servers, even on a runner without the Dedicated Server module.
+  public static class BuildSubtarget
+  {
+    public static int Resolve(BuildTarget target, Dictionary<string, string> options)
+    {
+      options.TryGetValue("standaloneBuildSubtarget", out var requested);
+
+      if (BuildPipeline.GetBuildTargetGroup(target) != BuildTargetGroup.Standalone)
+      {
+        if (!string.IsNullOrEmpty(requested))
+        {
+          Debug.LogWarning($"Ignoring standaloneBuildSubtarget \"{requested}\": it only applies to standalone targets, not {target}.");
+        }
+
+        return 0;
+      }
+
+      if (string.IsNullOrEmpty(requested))
+      {
+        return (int) StandaloneBuildSubtarget.Player;
+      }
+
+      if (!Enum.TryParse(requested, true, out StandaloneBuildSubtarget subtarget)
+          || !Enum.IsDefined(typeof(StandaloneBuildSubtarget), subtarget))
+      {
+        throw new ArgumentException($"Unknown standaloneBuildSubtarget \"{requested}\"; expected Player or Server.");
+      }
+
+      return (int) subtarget;
+    }
+  }
+}
+#endif

plugins/unity/src/unity-builder/dist/default-build-script/Assets/Editor/UnityBuilderAction/Builder.cs

@@ -89,14 +89,6 @@ public static void BuildProject()
         // Gather values from project
         var scenes = EditorBuildSettings.scenes.Where(scene => scene.enabled).Select(s => s.path).ToArray();
 
-#if UNITY_2021_2_OR_NEWER
-        // Determine subtarget
-        StandaloneBuildSubtarget buildSubtarget;
-        if (!options.TryGetValue("standaloneBuildSubtarget", out var subtargetValue) || !Enum.TryParse(subtargetValue, out buildSubtarget)) {
-          buildSubtarget = default;
-        }
-#endif
-
         BuildTarget buildTarget = (BuildTarget) Enum.Parse(typeof(BuildTarget), options["buildTarget"]);
 
         // Define BuildPlayerOptions
@@ -106,7 +98,7 @@ public static void BuildProject()
           target = buildTarget,
           options = buildOptions,
 #if UNITY_2021_2_OR_NEWER
-          subtarget = (int) buildSubtarget
+          subtarget = BuildSubtarget.Resolve(buildTarget, options)
 #endif
         };
 

plugins/unity/src/unity-builder/dist/default-build-script/Assets/Editor/UnityBuilderAction/Input/BuildSubtarget.cs

@@ -0,0 +1,44 @@
+#if UNITY_2021_2_OR_NEWER
+using System;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+
+namespace UnityBuilderAction.Input
+{
+  // Standalone targets build the Player unless -standaloneBuildSubtarget asks for something else.
+  // Handing Unity StandaloneBuildSubtarget.Default instead would make it reuse the subtarget
+  // persisted in the project's Library, so a Library that once built a Server keeps building
+  // Servers, even on a runner without the Dedicated Server module.
+  public static class BuildSubtarget
+  {
+    public static int Resolve(BuildTarget target, Dictionary<string, string> options)
+    {
+      options.TryGetValue("standaloneBuildSubtarget", out var requested);
+
+      if (BuildPipeline.GetBuildTargetGroup(target) != BuildTargetGroup.Standalone)
+      {
+        if (!string.IsNullOrEmpty(requested))
+        {
+          Debug.LogWarning($"Ignoring standaloneBuildSubtarget \"{requested}\": it only applies to standalone targets, not {target}.");
+        }
+
+        return 0;
+      }
+
+      if (string.IsNullOrEmpty(requested))
+      {
+        return (int) StandaloneBuildSubtarget.Player;
+      }
+
+      if (!Enum.TryParse(requested, true, out StandaloneBuildSubtarget subtarget)
+          || !Enum.IsDefined(typeof(StandaloneBuildSubtarget), subtarget))
+      {
+        throw new ArgumentException($"Unknown standaloneBuildSubtarget \"{requested}\"; expected Player or Server.");
+      }
+
+      return (int) subtarget;
+    }
+  }
+}
+#endif