Adds a better error message in the case of using ref and deref ex…

…pressions (FuelLabs#3687)

Instead of using the Rust `unimplemented!()` macro, Sway users now see
an "unimplemented" error from the Sway compiler when attempting to use
`ref` or `deref` expressions.

Closes FuelLabs#3677

Co-authored-by: emilyaherbert <[email protected]>

sway-core/src/transform/to_parsed_lang/convert_parse_tree.rs

@@ -1584,8 +1584,18 @@ fn expr_to_expression(
             }),
             span,
         },
-        Expr::Ref { .. } => unimplemented!(),
-        Expr::Deref { .. } => unimplemented!(),
+        Expr::Ref { ref_token, .. } => {
+            let error = ConvertParseTreeError::RefExprNotYetSupported {
+                span: ref_token.span(),
+            };
+            return Err(handler.emit_err(error.into()));
+        }
+        Expr::Deref { deref_token, .. } => {
+            let error = ConvertParseTreeError::DerefExprNotYetSupported {
+                span: deref_token.span(),
+            };
+            return Err(handler.emit_err(error.into()));
+        }
         Expr::Not { bang_token, expr } => {
             let expr = expr_to_expression(handler, engines, *expr)?;
             op_call("not", bang_token.span(), span, &[expr])?

sway-error/src/convert_parse_tree_error.rs

@@ -97,6 +97,10 @@ pub enum ConvertParseTreeError {
     CannotAnnotateDependency { span: Span },
     #[error("Expected dependency at the beginning before any other items.")]
     ExpectedDependencyAtBeginning { span: Span },
+    #[error("Ref expressions are not supported yet.")]
+    RefExprNotYetSupported { span: Span },
+    #[error("Deref expressions are not supported yet.")]
+    DerefExprNotYetSupported { span: Span },
 }
 
 impl Spanned for ConvertParseTreeError {
@@ -149,6 +153,8 @@ impl Spanned for ConvertParseTreeError {
             ConvertParseTreeError::CannotDocCommentDependency { span } => span.clone(),
             ConvertParseTreeError::CannotAnnotateDependency { span } => span.clone(),
             ConvertParseTreeError::ExpectedDependencyAtBeginning { span } => span.clone(),
+            ConvertParseTreeError::RefExprNotYetSupported { span } => span.clone(),
+            ConvertParseTreeError::DerefExprNotYetSupported { span } => span.clone(),
         }
     }
 }

test/src/e2e_vm_tests/test_programs/should_fail/ref_and_deref_expressions/Forc.lock

@@ -0,0 +1,3 @@
+[[package]]
+name = 'ref_and_deref_expressions'
+source = 'member'

test/src/e2e_vm_tests/test_programs/should_fail/ref_and_deref_expressions/Forc.toml

@@ -0,0 +1,6 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+license = "Apache-2.0"
+name = "ref_and_deref_expressions"
+entry = "main.sw"
+implicit-std = false

test/src/e2e_vm_tests/test_programs/should_fail/ref_and_deref_expressions/json_abi_oracle.json

@@ -0,0 +1,16 @@
+[
+  {
+    "attributes": null,
+    "inputs": [],
+    "name": "main",
+    "outputs": [
+      {
+        "components": null,
+        "name": "",
+        "type": "u32",
+        "typeArguments": null
+      }
+    ],
+    "type": "function"
+  }
+]

test/src/e2e_vm_tests/test_programs/should_fail/ref_and_deref_expressions/src/main.sw

@@ -0,0 +1,16 @@
+contract;
+
+abi MyContract {
+    fn test_function() -> bool;
+}
+
+impl MyContract for Contract {
+    fn test_function() -> bool {
+        foo(ref Vec::new());
+        true
+    }
+}
+
+pub fn foo(ref mut vec: Vec<u64>) {
+    vec.push(1);
+}

test/src/e2e_vm_tests/test_programs/should_fail/ref_and_deref_expressions/test.toml

@@ -0,0 +1,6 @@
+category = "fail"
+
+# check: $()error
+# nextln: ref_and_deref_expressions/src/main.sw:9:13
+# check: $()foo(ref Vec::new());
+# nextln: $()Ref expressions are not supported yet.