Add tests that some obvious problems give errors

test/error/DuplicateType.pth

@@ -0,0 +1,11 @@
+// Plinth Test
+// Compiler: DuplicateType.pth: 8:1-15: Duplicate type name: a type named 'Test' already exists in this compilation unit
+
+class Test
+{
+}
+
+interface Test
+{
+}
+

test/error/class/DuplicateField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateField.pth: 7:3-9: A field with the name 'x' already exists in 'Foo', so another field cannot be defined with the same name
+
+class Foo
+{
+  uint x;
+  Foo x;
+}

test/error/class/DuplicateFieldProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateFieldProperty.pth: 7:3-20: A field with the name 'x' already exists in 'Foo', so a property cannot be defined with the same name
+
+class Foo
+{
+  uint x;
+  property ulong x;
+}

test/error/class/DuplicateProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateProperty.pth: 7:3-19: A property with the name 'x' already exists in 'Foo', so another property cannot be defined with the same name
+
+class Foo
+{
+  property uint x;
+  property long x;
+}

test/error/class/DuplicatePropertyField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicatePropertyField.pth: 7:3-10: A property with the name 'x' already exists in 'Foo', so a field cannot be defined with the same name
+
+class Foo
+{
+  property ulong x;
+  uint x;
+}

test/error/class/DuplicateTypeParameter.pth

@@ -0,0 +1,7 @@
+// Plinth Test
+// Compiler: DuplicateTypeParameter.pth: 4:14: Duplicate type parameter: T
+
+class Foo<T, T>
+{
+}
+

test/error/compound/DuplicateField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateField.pth: 7:3-9: A field with the name 'x' already exists in 'Foo', so another field cannot be defined with the same name
+
+compound Foo
+{
+  uint x;
+  Foo x;
+}

test/error/compound/DuplicateFieldProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateFieldProperty.pth: 7:3-20: A field with the name 'x' already exists in 'Foo', so a property cannot be defined with the same name
+
+compound Foo
+{
+  uint x;
+  property ulong x;
+}

test/error/compound/DuplicateProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateProperty.pth: 7:3-19: A property with the name 'x' already exists in 'Foo', so another property cannot be defined with the same name
+
+compound Foo
+{
+  property uint x;
+  property long x;
+}

test/error/compound/DuplicatePropertyField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicatePropertyField.pth: 7:3-10: A property with the name 'x' already exists in 'Foo', so a field cannot be defined with the same name
+
+compound Foo
+{
+  property ulong x;
+  uint x;
+}

test/error/compound/DuplicateTypeParameter.pth

@@ -0,0 +1,7 @@
+// Plinth Test
+// Compiler: DuplicateTypeParameter.pth: 4:17: Duplicate type parameter: T
+
+compound Foo<T, T>
+{
+}
+

test/error/interface/Constructor.pth

@@ -0,0 +1,9 @@
+// Plinth Test
+// Compiler: Constructor.pth: 6:3-11: Interfaces cannot have constructors
+
+interface Test
+{
+  create()
+  {
+  }
+}

test/error/interface/DuplicateField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateField.pth: 7:3-16: A field with the name 'x' already exists in 'Foo', so another field cannot be defined with the same name
+
+interface Foo
+{
+  static uint x;
+  static Foo x;
+}

test/error/interface/DuplicateFieldProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateFieldProperty.pth: 7:3-27: A field with the name 'x' already exists in 'Foo', so a property cannot be defined with the same name
+
+interface Foo
+{
+  static uint x;
+  static property ulong x;
+}

test/error/interface/DuplicateProperty.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicateProperty.pth: 7:3-19: A property with the name 'x' already exists in 'Foo', so another property cannot be defined with the same name
+
+interface Foo
+{
+  property uint x;
+  property long x;
+}

test/error/interface/DuplicatePropertyField.pth

@@ -0,0 +1,8 @@
+// Plinth Test
+// Compiler: DuplicatePropertyField.pth: 7:3-17: A property with the name 'x' already exists in 'Foo', so a field cannot be defined with the same name
+
+interface Foo
+{
+  static property ulong x;
+  static uint x;
+}

test/error/interface/DuplicateTypeParameter.pth

@@ -0,0 +1,7 @@
+// Plinth Test
+// Compiler: DuplicateTypeParameter.pth: 4:18: Duplicate type parameter: T
+
+interface Foo<T, T>
+{
+}
+

test/error/interface/NativeUpcall.pth

@@ -0,0 +1,9 @@
+// Plinth Test
+// Compiler: NativeUpcall.pth: 6:3-36: Non-static methods on generic interfaces cannot be native up-calls
+
+interface Test<T>
+{
+  native "test" void nativeUpcall()
+  {
+  }
+}

test/error/interface/NonStaticBackedProperty.pth

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+// Plinth Test
+// Compiler: NonStaticBackedProperty.pth: 6:3-18: Interfaces cannot store (non-static) data - should this property be unbacked?
+
+interface Test
+{
+  property uint x
+  getter
+  {
+    return x;
+  };
+}

test/error/interface/NonStaticField.pth

@@ -0,0 +1,7 @@
+// Plinth Test
+// Compiler: NonStaticField.pth: 6:3-10: Interfaces cannot store (non-static) data
+
+interface Foo
+{
+  uint x;
+}

test/error/interface/NonStaticInitialiser.pth

@@ -0,0 +1,9 @@
+// Plinth Test
+// Compiler: NonStaticInitialiser.pth: 6:3: Interfaces cannot contain non-static initialisers
+
+interface Foo
+{
+  {
+    // this is an initialiser
+  }
+}

test/error/member/Property.pth

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+// Plinth Test
+// Compiler: Property.pth: 7:17-22: A property method cannot throw checked exceptions. Consider marking them as unchecked.
+
+class Test
+{
+  property uint foo
+  getter throws Alpha
+  {
+  };
+}