Add ReturnStatement test

This CL adds tests for the ReturnStatement AST node.

Bug: tint:11
Change-Id: Ib20e38e67e07e0ae03d359619cc260bc8d6e3a3b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/16668
Reviewed-by: Sarah Mashayekhi <sarahmashay@google.com>

src/CMakeLists.txt

@@ -227,6 +227,7 @@ set(TINT_TEST_SRCS
   ast/nop_statement_test.cc
   ast/regardless_statement_test.cc
   ast/relational_expression_test.cc
+  ast/return_statement_test.cc
   ast/set_decoration_test.cc
   ast/struct_member_test.cc
   ast/struct_member_offset_decoration_test.cc

src/ast/return_statement.cc

@@ -19,6 +19,8 @@ namespace ast {
 
 ReturnStatement::ReturnStatement() : Statement() {}
 
+ReturnStatement::ReturnStatement(const Source& source) : Statement(source) {}
+
 ReturnStatement::ReturnStatement(std::unique_ptr<Expression> value)
     : Statement(), value_(std::move(value)) {}
 
@@ -29,6 +31,9 @@ ReturnStatement::ReturnStatement(const Source& source,
 ReturnStatement::~ReturnStatement() = default;
 
 bool ReturnStatement::IsValid() const {
+  if (value_ != nullptr) {
+    return value_->IsValid();
+  }
   return true;
 }
 
@@ -38,7 +43,15 @@ void ReturnStatement::to_str(std::ostream& out, size_t indent) const {
 
   if (value_) {
     out << std::endl;
-    value_->to_str(out, indent);
+
+    make_indent(out, indent + 2);
+    out << "{" << std::endl;
+
+    value_->to_str(out, indent + 4);
+
+    make_indent(out, indent + 2);
+    out << "}" << std::endl;
+
     make_indent(out, indent);
   }
   out << "}" << std::endl;

src/ast/return_statement.h

@@ -30,6 +30,9 @@ class ReturnStatement : public Statement {
   /// Constructor
   ReturnStatement();
   /// Constructor
+  /// @param source the source information
+  explicit ReturnStatement(const Source& source);
+  /// Constructor
   /// @param value the return value
   explicit ReturnStatement(std::unique_ptr<Expression> value);
   /// Constructor

src/ast/return_statement_test.cc

@@ -0,0 +1,86 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/ast/return_statement.h"
+
+#include <sstream>
+
+#include "gtest/gtest.h"
+#include "src/ast/identifier_expression.h"
+
+namespace tint {
+namespace ast {
+
+using ReturnStatementTest = testing::Test;
+
+TEST_F(ReturnStatementTest, Creation) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  auto expr_ptr = expr.get();
+
+  ReturnStatement r(std::move(expr));
+  EXPECT_EQ(r.value(), expr_ptr);
+}
+
+TEST_F(ReturnStatementTest, Creation_WithSource) {
+  ReturnStatement r(Source{20, 2});
+  auto src = r.source();
+  EXPECT_EQ(src.line, 20);
+  EXPECT_EQ(src.column, 2);
+}
+
+TEST_F(ReturnStatementTest, IsReturn) {
+  ReturnStatement r;
+  EXPECT_TRUE(r.IsReturn());
+}
+
+TEST_F(ReturnStatementTest, IsValid_WithoutValue) {
+  ReturnStatement r;
+  EXPECT_TRUE(r.IsValid());
+}
+
+TEST_F(ReturnStatementTest, IsValid_WithValue) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  ReturnStatement r(std::move(expr));
+  EXPECT_TRUE(r.IsValid());
+}
+
+TEST_F(ReturnStatementTest, IsValid_InvalidValue) {
+  auto expr = std::make_unique<IdentifierExpression>("");
+  ReturnStatement r(std::move(expr));
+  EXPECT_FALSE(r.IsValid());
+}
+
+TEST_F(ReturnStatementTest, ToStr_WithValue) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  ReturnStatement r(std::move(expr));
+  std::ostringstream out;
+  r.to_str(out, 2);
+  EXPECT_EQ(out.str(), R"(  Return{
+    {
+      Identifier{expr}
+    }
+  }
+)");
+}
+
+TEST_F(ReturnStatementTest, ToStr_WithoutValue) {
+  ReturnStatement r;
+  std::ostringstream out;
+  r.to_str(out, 2);
+  EXPECT_EQ(out.str(), R"(  Return{}
+)");
+}
+
+}  // namespace ast
+}  // namespace tint