add new dynamic check errors and tests for variables

compiler/tests/statements/ternary_basic.leo

@@ -1,5 +1,5 @@
 function main(a: bool, b: bool) {
     let c = if a ? true : false;
 
-    const a = c == b;
+    const d = c == b;
 }

dynamic-check/src/dynamic_check.rs

@@ -299,12 +299,15 @@ impl Frame {
     ///
     /// Insert a variable into the symbol table in the current scope.
     ///
-    fn insert_variable(&mut self, name: String, type_: Type) -> Option<Type> {
+    fn insert_variable(&mut self, name: String, type_: Type, span: &Span) -> Result<(), FrameError> {
         // Modify the current scope.
         let scope = self.scopes.last_mut().unwrap();
 
         // Insert the variable name -> type.
-        scope.variables.insert(name, type_)
+        match scope.variables.insert(name.clone(), type_) {
+            Some(_type) => Err(FrameError::duplicate_variable(&name, span)),
+            None => Ok(()),
+        }
     }
 
     ///
@@ -459,24 +462,26 @@ impl Frame {
             // Insert variable into symbol table
             let variable = variables.names[0].clone();
 
-            // TODO (collinc97) throw error for duplicate variable definitions.
-            let _expect_none = self.insert_variable(variable.identifier.name, actual_type);
+            self.insert_variable(variable.identifier.name, actual_type, span)?;
         } else {
             // Expect a tuple type.
             let types = match actual_type {
                 Type::Tuple(types) => types,
-                _ => unimplemented!("expected a tuple type for multiple defined variables"),
+                _ => return Err(FrameError::not_enough_values(span)),
             };
 
             // Check number of variables == number of types.
             if types.len() != variables.names.len() {
-                unimplemented!("Incorrect number of defined variables")
+                return Err(FrameError::invalid_number_of_values(
+                    types.len(),
+                    variables.names.len(),
+                    span,
+                ));
             }
 
             // Insert variables into symbol table
             for (variable, type_) in variables.names.iter().zip(types) {
-                // TODO (collinc97) throw error for duplicate variable definitions.
-                let _expect_none = self.insert_variable(variable.identifier.name.clone(), type_);
+                self.insert_variable(variable.identifier.name.clone(), type_, span)?;
             }
         }
 
@@ -605,7 +610,7 @@ impl Frame {
     ) -> Result<(), FrameError> {
         // Insert variable into symbol table with u32 type.
         let u32_type = Type::IntegerType(IntegerType::U32);
-        let _expect_none = self.insert_variable(identifier.name.to_owned(), u32_type.clone());
+        let _expect_none = self.insert_variable(identifier.name.to_owned(), u32_type.clone(), span);
 
         // Parse `from` and `to` expressions.
         let from_type = self.parse_expression(from)?;
@@ -1043,7 +1048,7 @@ impl Frame {
 
         // Check the length of the circuit members.
         if circuit_type.variables.len() != members.len() {
-            return Err(FrameError::num_variables(
+            return Err(FrameError::num_circuit_variables(
                 circuit_type.variables.len(),
                 members.len(),
                 span,

dynamic-check/src/errors/dynamic_check.rs

@@ -27,18 +27,6 @@ pub enum DynamicCheckError {
 
     #[error("{}", _0)]
     FrameError(#[from] FrameError),
-    //
-    // #[error("{}", _0)]
-    // ExpressionError(#[from] ExpressionError),
-    //
-    // #[error("{}", _0)]
-    // FunctionError(#[from] FunctionError),
-    //
-    // #[error("{}", _0)]
-    // StatementError(#[from] StatementError),
-    //
-    // #[error("{}", _0)]
-    // ProgramError(#[from] ProgramError),
 }
 
 impl DynamicCheckError {
@@ -49,10 +37,6 @@ impl DynamicCheckError {
         match self {
             DynamicCheckError::Error(error) => error.set_path(path),
             DynamicCheckError::FrameError(error) => error.set_path(path),
-            // DynamicCheckError::ExpressionError(error) => error.set_path(path),
-            // DynamicCheckError::FunctionError(error) => error.set_path(path),
-            // DynamicCheckError::StatementError(error) => error.set_path(path),
-            // DynamicCheckError::ProgramError(error) => error.set_path(path),
         }
     }
 }

dynamic-check/src/errors/frame.rs

@@ -65,6 +65,15 @@ impl FrameError {
         Self::new_from_span(message, span.to_owned())
     }
 
+    ///
+    /// Two variables have been defined with the same name.
+    ///
+    pub fn duplicate_variable(name: &str, span: &Span) -> Self {
+        let message = format!("Duplicate variable definition found for `{}`", name);
+
+        Self::new_from_span(message, span.to_owned())
+    }
+
     ///
     /// Attempted to call non-static member using `::`.
     ///
@@ -83,6 +92,15 @@ impl FrameError {
         Self::new_from_span(message, identifier.span.to_owned())
     }
 
+    ///
+    /// Attempted to create a circuit with the incorrect number of member variables.
+    ///
+    pub fn num_circuit_variables(expected: usize, actual: usize, span: &Span) -> Self {
+        let message = format!("Circuit expected {} variables, found {} variables.", expected, actual);
+
+        Self::new_from_span(message, span.clone())
+    }
+
     ///
     /// Attempted to call a function with the incorrect number of inputs.
     ///
@@ -95,15 +113,6 @@ impl FrameError {
         Self::new_from_span(message, span.clone())
     }
 
-    ///
-    /// Attempted to create a circuit with the incorrect number of member variables.
-    ///
-    pub fn num_variables(expected: usize, actual: usize, span: &Span) -> Self {
-        let message = format!("Circuit expected {} variables, found {} variables.", expected, actual);
-
-        Self::new_from_span(message, span.clone())
-    }
-
     ///
     /// Attempted to call a circuit type that is not defined in the current context.
     ///
@@ -139,4 +148,25 @@ impl FrameError {
 
         Self::new_from_span(message, identifier.span.to_owned())
     }
+
+    ///
+    /// Attempted to assign a tuple of variables to a single value.
+    ///
+    pub fn not_enough_values(span: &Span) -> Self {
+        let message = "Expected a tuple type for multiple defined variables".to_string();
+
+        Self::new_from_span(message, span.to_owned())
+    }
+
+    ///
+    /// Attempted to assign a tuple with a different number of variables than values.
+    ///
+    pub fn invalid_number_of_values(expected: usize, actual: usize, span: &Span) -> Self {
+        let message = format!(
+            "Incorrect number of defined variables. Expected `{}`, found `{}`.",
+            expected, actual
+        );
+
+        Self::new_from_span(message, span.to_owned())
+    }
 }

dynamic-check/tests/mod.rs

@@ -13,13 +13,14 @@
 
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
+pub mod variables;
 
 use leo_ast::LeoAst;
 use leo_dynamic_check::DynamicCheck;
 
 use leo_imports::ImportParser;
-use leo_static_check::StaticCheck;
-use leo_typed::{Input, LeoTypedAst};
+use leo_static_check::{StaticCheck, SymbolTable};
+use leo_typed::{Input, LeoTypedAst, Program};
 use std::path::PathBuf;
 
 const TEST_PROGRAM_PATH: &str = "";
@@ -27,7 +28,8 @@ const TEST_PROGRAM_NAME: &str = "test";
 
 /// A helper struct to test a `DynamicCheck`.
 pub struct TestDynamicCheck {
-    dynamic_check: DynamicCheck,
+    program: Program,
+    symbol_table: SymbolTable,
 }
 
 impl TestDynamicCheck {
@@ -54,14 +56,24 @@ impl TestDynamicCheck {
         // Create static check.
         let symbol_table = StaticCheck::run_with_input(&program, &import_parser, &input).unwrap();
 
-        // Create dynamic check
-        let dynamic_check = DynamicCheck::new(&program, symbol_table).unwrap();
-
-        Self { dynamic_check }
+        // Store fields for new dynamic check.
+        Self { program, symbol_table }
     }
 
     pub fn solve(self) {
-        self.dynamic_check.solve().unwrap();
+        let dynamic_check = DynamicCheck::new(&self.program, self.symbol_table).unwrap();
+
+        dynamic_check.solve().unwrap();
+    }
+
+    pub fn expect_create_error(self) {
+        assert!(DynamicCheck::new(&self.program, self.symbol_table).is_err());
+    }
+
+    pub fn expect_solve_error(self) {
+        let dynamic_check = DynamicCheck::new(&self.program, self.symbol_table).unwrap();
+
+        assert!(dynamic_check.solve().is_err());
     }
 }
 

dynamic-check/tests/variables/duplicate_variable.leo

@@ -0,0 +1,4 @@
+function main() {
+    let a = 1u8;
+    let a = 2u8; // Redefining variables with the same name is unsafe in Leo.
+}

dynamic-check/tests/variables/duplicate_variable_multi.leo

@@ -0,0 +1,3 @@
+function main() {
+    let (a, a) = (2u8, 2u8); // Defining multiple variables with the same name is unsafe in Leo.
+}

dynamic-check/tests/variables/mod.rs

@@ -0,0 +1,49 @@
+// Copyright (C) 2019-2020 Aleo Systems Inc.
+// This file is part of the Leo library.
+
+// The Leo library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// The Leo library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
+
+use crate::TestDynamicCheck;
+
+#[test]
+fn test_duplicate_variable() {
+    let bytes = include_bytes!("duplicate_variable.leo");
+    let check = TestDynamicCheck::new(bytes);
+
+    check.expect_create_error();
+}
+
+#[test]
+fn test_duplicate_variable_multi() {
+    let bytes = include_bytes!("duplicate_variable_multi.leo");
+    let check = TestDynamicCheck::new(bytes);
+
+    check.expect_create_error();
+}
+
+#[test]
+fn test_not_enough_values() {
+    let bytes = include_bytes!("not_enough_values.leo");
+    let check = TestDynamicCheck::new(bytes);
+
+    check.expect_create_error();
+}
+
+#[test]
+fn test_too_many_values() {
+    let bytes = include_bytes!("too_many_values.leo");
+    let check = TestDynamicCheck::new(bytes);
+
+    check.expect_create_error();
+}

dynamic-check/tests/variables/not_enough_values.leo

@@ -0,0 +1,3 @@
+function main() {
+    let (a, b): (u8, u8) = 1; // A tuple of values must be used when defining two variables.
+}

dynamic-check/tests/variables/too_many_values.leo

@@ -0,0 +1,3 @@
+function main() {
+    let (a, b): (u8, u8) = (1, 2, 3); // Cannot assign 2 variables to 3 values.
+}