GDScript: Add return type covariance and parameter type contravariance

18 files changed, 138 insertions, 0 deletions

diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.gd
new file mode 100644
index 0000000000..fdf22f6843
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.gd
@@ -0,0 +1,10 @@
+class A:
+	func f(_p: Object):
+		pass
+
+class B extends A:
+	func f(_p: Node):
+		pass
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.out b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.out
new file mode 100644
index 0000000000..c6a7e40e8c
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_1.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f(Object) -> Variant".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.gd
new file mode 100644
index 0000000000..e4094f1d76
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.gd
@@ -0,0 +1,10 @@
+class A:
+	func f(_p: Variant):
+		pass
+
+class B extends A:
+	func f(_p: Node): # No `is_type_compatible()` misuse.
+		pass
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.out b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.out
new file mode 100644
index 0000000000..52a6efc6fc
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_2.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f(Variant) -> Variant".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.gd
new file mode 100644
index 0000000000..17663da4f6
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.gd
@@ -0,0 +1,10 @@
+class A:
+	func f(_p: int):
+		pass
+
+class B extends A:
+	func f(_p: float): # No implicit conversion.
+		pass
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.out b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.out
new file mode 100644
index 0000000000..7a6207fd45
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_param_type_invalid_contravariance_3.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f(int) -> Variant".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.gd
new file mode 100644
index 0000000000..6dfa75ecbc
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.gd
@@ -0,0 +1,10 @@
+class A:
+	func f() -> Node:
+		return null
+
+class B extends A:
+	func f() -> Object:
+		return null
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.out b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.out
new file mode 100644
index 0000000000..e680b2bd77
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_1.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f() -> Node".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.gd
new file mode 100644
index 0000000000..366494b94f
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.gd
@@ -0,0 +1,10 @@
+class A:
+	func f() -> Node:
+		return null
+
+class B extends A:
+	func f() -> Variant: # No `is_type_compatible()` misuse.
+		return null
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.out b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.out
new file mode 100644
index 0000000000..e680b2bd77
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_2.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f() -> Node".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.gd
new file mode 100644
index 0000000000..2cb4e7c616
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.gd
@@ -0,0 +1,10 @@
+class A:
+	func f() -> Node:
+		return null
+
+class B extends A:
+	func f() -> void: # No `is_type_compatible()` misuse.
+		return
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.out b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.out
new file mode 100644
index 0000000000..e680b2bd77
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_3.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f() -> Node".
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.gd b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.gd
new file mode 100644
index 0000000000..2cabce46f5
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.gd
@@ -0,0 +1,10 @@
+class A:
+	func f() -> float:
+		return 0.0
+
+class B extends A:
+	func f() -> int: # No implicit conversion.
+		return 0
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.out b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.out
new file mode 100644
index 0000000000..72f2c493d4
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/errors/function_return_type_invalid_covariance_4.out
@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+The function signature doesn't match the parent. Parent signature is "f() -> float".
diff --git a/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.gd b/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.gd
new file mode 100644
index 0000000000..a43c233625
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.gd
@@ -0,0 +1,20 @@
+class A:
+	func int_to_variant(_p: int): pass
+	func node_to_variant(_p: Node): pass
+	func node_2d_to_node(_p: Node2D): pass
+
+	func variant_to_untyped(_p: Variant): pass
+	func int_to_untyped(_p: int): pass
+	func node_to_untyped(_p: Node): pass
+
+class B extends A:
+	func int_to_variant(_p: Variant): pass
+	func node_to_variant(_p: Variant): pass
+	func node_2d_to_node(_p: Node): pass
+
+	func variant_to_untyped(_p): pass
+	func int_to_untyped(_p): pass
+	func node_to_untyped(_p): pass
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.out b/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.out
new file mode 100644
index 0000000000..d73c5eb7cd
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/features/function_param_type_contravariance.out
@@ -0,0 +1 @@
+GDTEST_OK
diff --git a/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.gd b/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.gd
new file mode 100644
index 0000000000..4de50b6731
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.gd
@@ -0,0 +1,32 @@
+class A:
+	func variant_to_int() -> Variant: return 0
+	func variant_to_node() -> Variant: return null
+	func node_to_node_2d() -> Node: return null
+
+	func untyped_to_void(): pass
+	func untyped_to_variant(): pass
+	func untyped_to_int(): pass
+	func untyped_to_node(): pass
+
+	func void_to_untyped() -> void: pass
+	func variant_to_untyped() -> Variant: return null
+	func int_to_untyped() -> int: return 0
+	func node_to_untyped() -> Node: return null
+
+class B extends A:
+	func variant_to_int() -> int: return 0
+	func variant_to_node() -> Node: return null
+	func node_to_node_2d() -> Node2D: return null
+
+	func untyped_to_void() -> void: pass
+	func untyped_to_variant() -> Variant: return null
+	func untyped_to_int() -> int: return 0
+	func untyped_to_node() -> Node: return null
+
+	func void_to_untyped(): pass
+	func variant_to_untyped(): pass
+	func int_to_untyped(): pass
+	func node_to_untyped(): pass
+
+func test():
+	pass
diff --git a/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.out b/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.out
new file mode 100644
index 0000000000..d73c5eb7cd
--- /dev/null
+++ b/modules/gdscript/tests/scripts/analyzer/features/function_return_type_covariance.out
@@ -0,0 +1 @@
+GDTEST_OK