9 files changed, 147 insertions, 12 deletions
diff --git a/tests/diagnostics/extension-visibility-a.slang b/tests/diagnostics/extension-visibility-a.slang
index 97e4ef85c..162320d51 100644
--- a/tests/diagnostics/extension-visibility-a.slang
+++ b/tests/diagnostics/extension-visibility-a.slang
@@ -1,17 +1,17 @@
 // extension-visibility-a.slang
 
-interface IThing
+public interface IThing
 {
-	int getValue();
+	public int getValue();
 }
 
 // Note: not implementing the interface here!
-struct MyThing
+public struct MyThing
 {
-	int value;
+	public int value;
 }
 
-int helper<T : IThing>(T thing)
+public int helper<T : IThing>(T thing)
 {
 	return thing.getValue();
-}
-\ No newline at end of file
+}
diff --git a/tests/diagnostics/extension-visibility-b.slang b/tests/diagnostics/extension-visibility-b.slang
index 7848f2a56..dbefe66e7 100644
--- a/tests/diagnostics/extension-visibility-b.slang
+++ b/tests/diagnostics/extension-visibility-b.slang
@@ -2,7 +2,7 @@
 
 import extension_visibility_a;
 
-extension MyThing : IThing
+public extension MyThing : IThing
 {
-	int getValue() { return value; }	
+	public int getValue() { return value; }	
 }
diff --git a/tests/diagnostics/extension-visibility-c.slang b/tests/diagnostics/extension-visibility-c.slang
index 2d7a5224d..71680b31e 100644
--- a/tests/diagnostics/extension-visibility-c.slang
+++ b/tests/diagnostics/extension-visibility-c.slang
@@ -3,7 +3,7 @@
 import extension_visibility_a;
 import extension_visibility_b;
 
-int works(MyThing thing)
+public int works(MyThing thing)
 {
 	return helper(thing);
 }
diff --git a/tests/diagnostics/extension-visibility.slang.expected b/tests/diagnostics/extension-visibility.slang.expected
index 732ff4189..eed86715d 100644
--- a/tests/diagnostics/extension-visibility.slang.expected
+++ b/tests/diagnostics/extension-visibility.slang.expected
@@ -3,9 +3,9 @@ standard error = {
 tests/diagnostics/extension-visibility.slang(17): error 39999: could not specialize generic for arguments of type (MyThing)
     return helper(thing);
                  ^
-tests/diagnostics/extension-visibility-a.slang(14): note 39999: see declaration of func helper<T>(T) -> int
-int helper<T : IThing>(T thing)
-    ^~~~~~
+tests/diagnostics/extension-visibility-a.slang(14): note 39999: see declaration of public func helper<T>(T) -> int
+public int helper<T : IThing>(T thing)
+           ^~~~~~
 }
 standard output = {
 }
diff --git a/tests/diagnostics/internal-visibility/that-module-impl.slang b/tests/diagnostics/internal-visibility/that-module-impl.slang
new file mode 100644
index 000000000..893510afe
--- /dev/null
+++ b/tests/diagnostics/internal-visibility/that-module-impl.slang
@@ -0,0 +1,17 @@
+implementing "that-module";
+
+
+public void publicFunc2() { }
+
+internal void internalFunc1() {}
+
+public struct PublicStruct
+{
+    int x;
+    public int y;
+}
+
+public namespace Namespace
+{
+    public static int publicVar2;
+}
diff --git a/tests/diagnostics/internal-visibility/that-module.slang b/tests/diagnostics/internal-visibility/that-module.slang
new file mode 100644
index 000000000..b072c7231
--- /dev/null
+++ b/tests/diagnostics/internal-visibility/that-module.slang
@@ -0,0 +1,25 @@
+module "that-module";
+
+__include "that-module-impl";
+
+void internalMethod();
+
+public void publicMethod();
+
+public namespace Namespace
+{
+    static int internalVar;
+
+    public static int publicVar;
+}
+
+enum InternalEnum
+{
+    A,B,C
+}
+public enum PublicEnum
+{
+    D,E,F
+}
+
+struct InternalStruct { int x; }
diff --git a/tests/diagnostics/internal-visibility/this-module.slang b/tests/diagnostics/internal-visibility/this-module.slang
new file mode 100644
index 000000000..98e0f3d08
--- /dev/null
+++ b/tests/diagnostics/internal-visibility/this-module.slang
@@ -0,0 +1,26 @@
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK):
+
+module "this-module";
+
+import "that-module";
+
+void test()
+{
+    PublicStruct s;
+    // CHECK:{{.*}}(11): error 30600:
+    s.x = 1; // Error.
+    // CHECK-NOT:{{.*}}error
+    s.y = 2; // OK.
+    publicMethod(); // OK.
+    publicFunc2();  // OK.
+    Namespace.publicVar = 1; // OK.
+    Namespace.publicVar2 = 1; // OK.
+    // CHECK:{{.*}}(19): error 30600:
+    Namespace.internalVar = 1; // error.
+    // CHECK:{{.*}}(21): error 30600:
+    InternalEnum e; // Error.
+    // CHECK:{{.*}}(23): error 30600:
+    InternalStruct s1; // Error.
+    // CHECK:{{.*}}(25): error 30600:
+    internalMethod(); // Error.
+}
diff --git a/tests/diagnostics/private-visibility.slang b/tests/diagnostics/private-visibility.slang
new file mode 100644
index 000000000..7c0bad970
--- /dev/null
+++ b/tests/diagnostics/private-visibility.slang
@@ -0,0 +1,44 @@
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK):
+
+struct MyType
+{
+    private int member;
+    private int func()
+    {
+        return member;
+    }
+    struct SubType
+    {
+        int member2;
+        int func2(MyType m)
+        {
+            return m.member + member2; // OK.
+        }
+    }
+    int func1() { return member; }
+
+    private __init() { member = 0; }
+    
+    private __subscript(int i)->int
+    {
+        get { return member; }
+        set { member = newValue; }
+    }
+    // CHECK:{{.*}}(28): error 30601:
+    public void publicMethod() {} // ERROR.
+}
+
+void test()
+{
+    // CHECK:{{.*}}(34): error 30600:
+    MyType t; // ERROR.
+    // CHECK-NOT:{{.*}}error
+    t.func1(); // OK.
+    // CHECK:{{.*}}(38): error 30600:
+    t.func(); // ERROR.
+    // CHECK:{{.*}}(40): error 30600:
+    t[0] = 1; // ERROR.
+
+    // CHECK:{{.*}}(43): error 30600:
+    t.member = 2;
+}
diff --git a/tests/diagnostics/visibility.slang b/tests/diagnostics/visibility.slang
new file mode 100644
index 000000000..724ec30e7
--- /dev/null
+++ b/tests/diagnostics/visibility.slang
@@ -0,0 +1,23 @@
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK):
+
+// CHECK-DAG:{{.*}}(4): error 30603
+private struct MyStruct
+{}
+
+struct IS
+{
+    // CHECK-DAG:{{.*}}(10): error 30601
+    public void fp();
+}
+
+// CHECK-DAG:{{.*}}(14): error 30604
+public IS f() {}
+
+public struct PS
+{
+    // CHECK-DAG:{{.*}}(19): error 30604
+    public IS ii;
+
+    // CHECK-DAG:{{.*}}(22): error 30604
+    public property IS ii2 { get { return {}; } };
+}