tests: add NSObjectController tests

ChangeLog

@@ -43,6 +43,14 @@
 	path for a root node rather than nil, matching AppKit.
 	* Tests/gui/NSTreeNode/basic.m: Check the root index path.
 
+2026-07-12 Todd White <todd.white@thalion.global>
+
+	* Tests/gui/NSObjectController/basic.m:
+	* Tests/gui/NSObjectController/TestInfo:
+	Add tests for NSObjectController: the defaults, newObject, the content
+	and selected objects round-trip, add: and remove:, and how the
+	editable flag gates canAdd and canRemove.
+
 2026-07-12 Todd White <todd.white@thalion.global>
 
 	* Tests/gui/NSTreeNode/basic.m:

Tests/gui/NSObjectController/basic.m

@@ -0,0 +1,73 @@
+/* Coverage for NSObjectController: the defaults, newObject, the content and
+ * selected objects round-trip, add: and remove:, and how the editable flag
+ * gates canAdd and canRemove.  These are plain controller operations and need
+ * no backend.
+ */
+#include "Testing.h"
+#include <Foundation/Foundation.h>
+#include <AppKit/NSObjectController.h>
+
+int
+main(int argc, char **argv)
+{
+  CREATE_AUTORELEASE_POOL(arp);
+
+  START_SET("defaults")
+    NSObjectController	*oc = AUTORELEASE([[NSObjectController alloc] init]);
+
+    PASS([oc content] == nil, "a new controller has no content");
+    PASS([oc objectClass] == [NSMutableDictionary class],
+      "the default object class is NSMutableDictionary");
+    PASS([oc isEditable] == YES, "a new controller is editable");
+    PASS([oc automaticallyPreparesContent] == NO,
+      "a new controller does not automatically prepare content");
+    PASS([[oc selectedObjects] count] == 0,
+      "a new controller has no selected objects");
+    PASS([oc canAdd] == YES, "an editable controller can add");
+    PASS([oc canRemove] == NO, "a controller with no content cannot remove");
+  END_SET("defaults")
+
+  START_SET("newObject")
+    NSObjectController	*oc = AUTORELEASE([[NSObjectController alloc] init]);
+
+    PASS([[oc newObject] isKindOfClass: [NSMutableDictionary class]],
+      "newObject makes an instance of the object class");
+  END_SET("newObject")
+
+  START_SET("content and selection")
+    NSObjectController	*oc = AUTORELEASE([[NSObjectController alloc] init]);
+    NSMutableDictionary	*d = [NSMutableDictionary dictionary];
+
+    [oc setContent: d];
+    PASS([oc content] == d, "setContent: round trips");
+    PASS([[oc selectedObjects] count] == 1
+      && [[oc selectedObjects] objectAtIndex: 0] == d,
+      "the content is the selected object");
+    PASS([oc canRemove] == YES, "a controller with content can remove");
+
+    oc = AUTORELEASE([[NSObjectController alloc] initWithContent: d]);
+    PASS([oc content] == d, "initWithContent: stores the content");
+  END_SET("content and selection")
+
+  START_SET("the editable flag gates adding and removing")
+    NSObjectController	*oc = AUTORELEASE([[NSObjectController alloc]
+      initWithContent: [NSMutableDictionary dictionary]]);
+
+    [oc setEditable: NO];
+    PASS([oc canAdd] == NO, "a non-editable controller cannot add");
+    PASS([oc canRemove] == NO, "a non-editable controller cannot remove");
+  END_SET("the editable flag gates adding and removing")
+
+  START_SET("addObject: and removeObject:")
+    NSObjectController	*oc = AUTORELEASE([[NSObjectController alloc] init]);
+    NSMutableDictionary	*d = [NSMutableDictionary dictionary];
+
+    [oc addObject: d];
+    PASS([oc content] == d, "addObject: sets the content");
+    [oc removeObject: d];
+    PASS([oc content] == nil, "removeObject: clears the content");
+  END_SET("addObject: and removeObject:")
+
+  DESTROY(arp);
+  return 0;
+}