Add a diagnostics test. (#6268)

crates/cairo-lang-semantic/src/expr/test.rs

@@ -57,6 +57,7 @@ cairo_lang_test_utils::test_file_test!(
         statements: "statements",
         structure: "structure",
         while_: "while",
+        impl_: "impl",
     },
     test_function_diagnostics
 );

crates/cairo-lang-semantic/src/expr/test_data/impl

@@ -0,0 +1,69 @@
+//! > Unknown types in trait/impl methods.
+
+//! > test_runner_name
+test_function_diagnostics(expect_diagnostics: true)
+
+//! > function
+fn foo() {}
+
+//! > function_name
+foo
+
+//! > module_code
+trait MyTrait {
+    fn foo(x: u8, y: T, z: u8) -> u8;
+    fn bar() -> T;
+}
+
+impl MyImpl of MyTrait {
+    fn foo(x: T, y: u8, z: u16) -> T {}
+    fn bar() -> u8 {
+        0
+    }
+}
+
+//! > expected_diagnostics
+error: Type not found.
+ --> lib.cairo:2:22
+    fn foo(x: u8, y: T, z: u8) -> u8;
+                     ^
+
+error: Type not found.
+ --> lib.cairo:3:17
+    fn bar() -> T;
+                ^
+
+error: Type not found.
+ --> lib.cairo:7:15
+    fn foo(x: T, y: u8, z: u16) -> T {}
+              ^
+
+error: Type not found.
+ --> lib.cairo:7:36
+    fn foo(x: T, y: u8, z: u16) -> T {}
+                                   ^
+
+error: Parameter type of impl function `MyImpl::foo` is incompatible with `MyTrait::foo`. Expected: `core::integer::u8`, actual: `<missing>`.
+ --> lib.cairo:7:15
+    fn foo(x: T, y: u8, z: u16) -> T {}
+              ^
+
+error: Parameter type of impl function `MyImpl::foo` is incompatible with `MyTrait::foo`. Expected: `<missing>`, actual: `core::integer::u8`.
+ --> lib.cairo:7:21
+    fn foo(x: T, y: u8, z: u16) -> T {}
+                    ^^
+
+error: Parameter type of impl function `MyImpl::foo` is incompatible with `MyTrait::foo`. Expected: `core::integer::u8`, actual: `core::integer::u16`.
+ --> lib.cairo:7:28
+    fn foo(x: T, y: u8, z: u16) -> T {}
+                           ^*^
+
+error: Return type of impl function `MyImpl::foo` is incompatible with `MyTrait::foo`. Expected: `core::integer::u8`, actual: `<missing>`.
+ --> lib.cairo:7:36
+    fn foo(x: T, y: u8, z: u16) -> T {}
+                                   ^
+
+error: Return type of impl function `MyImpl::bar` is incompatible with `MyTrait::bar`. Expected: `<missing>`, actual: `core::integer::u8`.
+ --> lib.cairo:8:17
+    fn bar() -> u8 {
+                ^^