fix: better tests to check for unused struct error

compiler/noirc_frontend/src/tests/unused_items.rs

@@ -332,13 +332,15 @@ fn considers_struct_as_constructed_if_trait_method_is_called() {
 #[test]
 fn considers_struct_as_constructed_if_mentioned_in_let_type() {
     let src = "
-    pub struct Bar {}
+    struct Bar {}
 
-    pub fn foo(array: [Bar; 1]) {
+    fn foo(array: [Bar; 1]) {
         let _: Bar = array[0];
     }
 
-    fn main() {}
+    fn main() {
+        let _ = foo;
+    }
     ";
     assert_no_errors!(src);
 }
@@ -347,13 +349,15 @@ fn considers_struct_as_constructed_if_mentioned_in_let_type() {
 #[test]
 fn considers_struct_as_constructed_if_mentioned_in_return_type() {
     let src = "
-    pub struct Bar {}
+    struct Bar {}
 
-    pub fn foo(array: [Bar; 1]) -> Bar {
+    fn foo(array: [Bar; 1]) -> Bar {
         array[0]
     }
 
-    fn main() {}
+    fn main() {
+        let _ = foo;
+    }
     ";
     assert_no_errors!(src);
 }
@@ -387,3 +391,21 @@ fn considers_struct_as_constructed_if_passed_in_generic_args_in_function_call()
     ";
     assert_no_errors!(src);
 }
+
+#[named]
+#[test]
+fn does_not_consider_struct_as_constructed_if_mentioned_in_function_argument() {
+    let src = "
+    struct Bar {}
+           ^^^ struct `Bar` is never constructed
+           ~~~ struct is never constructed
+
+    fn foo(_: [Bar; 1]) {}
+
+    fn main() {
+        foo();
+        ^^^^^ Function expects 1 parameter but 0 were given
+    }
+    ";
+    check_errors!(src);
+}

test_programs/compile_failure/noirc_frontend_tests_unused_items_does_not_consider_struct_as_constructed_if_mentioned_in_function_argument/Nargo.toml

@@ -0,0 +1,7 @@
+
+            [package]
+            name = "noirc_frontend_tests_unused_items_does_not_consider_struct_as_constructed_if_mentioned_in_function_argument"
+            type = "bin"
+            authors = [""]
+
+            [dependencies]

test_programs/compile_failure/noirc_frontend_tests_unused_items_does_not_consider_struct_as_constructed_if_mentioned_in_function_argument/src/main.nr

@@ -0,0 +1,9 @@
+
+    struct Bar {}
+
+    fn foo(_: [Bar; 1]) {}
+
+    fn main() {
+        foo();
+    }
+

test_programs/compile_failure/noirc_frontend_tests_unused_items_does_not_consider_struct_as_constructed_if_mentioned_in_function_argument/src_hash.txt

@@ -0,0 +1 @@
+6625675327575863409

test_programs/compile_failure/noirc_frontend_tests_unused_items_does_not_consider_struct_as_constructed_if_mentioned_in_function_argument/stderr.txt

@@ -0,0 +1,15 @@
+warning: struct `Bar` is never constructed
+  ┌─ src/main.nr:2:12
+  │
+2 │     struct Bar {}
+  │            --- struct is never constructed
+  │
+
+error: Function expects 1 parameter but 0 were given
+  ┌─ src/main.nr:7:9
+  │
+7 │         foo();
+  │         -----
+  │
+
+Aborting due to 1 previous error

test_programs/compile_success_no_bug/noirc_frontend_tests_unused_items_considers_struct_as_constructed_if_mentioned_in_let_type/src/main.nr

@@ -1,9 +1,11 @@
 
-    pub struct Bar {}
+    struct Bar {}
 
-    pub fn foo(array: [Bar; 1]) {
+    fn foo(array: [Bar; 1]) {
         let _: Bar = array[0];
     }
 
-    fn main() {}
+    fn main() {
+        let _ = foo;
+    }
 

test_programs/compile_success_no_bug/noirc_frontend_tests_unused_items_considers_struct_as_constructed_if_mentioned_in_let_type/src_hash.txt

@@ -1 +1 @@
-38851938633219158
+12368942904043175809

test_programs/compile_success_no_bug/noirc_frontend_tests_unused_items_considers_struct_as_constructed_if_mentioned_in_return_type/src/main.nr

@@ -1,9 +1,11 @@
 
-    pub struct Bar {}
+    struct Bar {}
 
-    pub fn foo(array: [Bar; 1]) -> Bar {
+    fn foo(array: [Bar; 1]) -> Bar {
         array[0]
     }
 
-    fn main() {}
+    fn main() {
+        let _ = foo;
+    }
 

test_programs/compile_success_no_bug/noirc_frontend_tests_unused_items_considers_struct_as_constructed_if_mentioned_in_return_type/src_hash.txt

@@ -1 +1 @@
-2517654725056587726
+1898526012180092460