Add ContinueStatement unit test

This CL adds tests for the continue statement AST node.

Bug: tint:11
Change-Id: I6339947c338b4b035f7947cb45e33bf2dcb6fe3e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/16464
Commit-Queue: Sarah Mashayekhi <sarahmashay@google.com>
Reviewed-by: Sarah Mashayekhi <sarahmashay@google.com>
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8b89ac3..6846c12 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -204,6 +204,7 @@
   ast/case_statement_test.cc
   ast/cast_expression_test.cc
   ast/const_initializer_expression_test.cc
+  ast/continue_statement_test.cc
   ast/entry_point_test.cc
   ast/import_test.cc
   ast/int_literal_test.cc
diff --git a/src/ast/continue_statement.cc b/src/ast/continue_statement.cc
index e154455..0485020 100644
--- a/src/ast/continue_statement.cc
+++ b/src/ast/continue_statement.cc
@@ -17,6 +17,11 @@
 namespace tint {
 namespace ast {
 
+ContinueStatement::ContinueStatement() : Statement() {}
+
+ContinueStatement::ContinueStatement(const Source& source)
+    : Statement(source) {}
+
 ContinueStatement::ContinueStatement(StatementCondition condition,
                                      std::unique_ptr<Expression> conditional)
     : Statement(),
@@ -33,24 +38,26 @@
 ContinueStatement::~ContinueStatement() = default;
 
 bool ContinueStatement::IsValid() const {
-  return condition_ == StatementCondition::kNone || conditional_ != nullptr;
+  if (condition_ == StatementCondition::kNone)
+    return conditional_ == nullptr;
+
+  return conditional_ && conditional_->IsValid();
 }
 
 void ContinueStatement::to_str(std::ostream& out, size_t indent) const {
   make_indent(out, indent);
-  out << "Continue";
+  out << "Continue{";
 
   if (condition_ != StatementCondition::kNone) {
-    out << "{" << std::endl;
+    out << std::endl;
 
     make_indent(out, indent + 2);
     out << condition_ << std::endl;
     conditional_->to_str(out, indent + 2);
 
     make_indent(out, indent);
-    out << "}";
   }
-  out << std::endl;
+  out << "}" << std::endl;
 }
 
 }  // namespace ast
diff --git a/src/ast/continue_statement.h b/src/ast/continue_statement.h
index 8cadbb7..26789f9 100644
--- a/src/ast/continue_statement.h
+++ b/src/ast/continue_statement.h
@@ -31,6 +31,9 @@
   /// Constructor
   ContinueStatement();
   /// Constructor
+  /// @param source the initializer source
+  explicit ContinueStatement(const Source& source);
+  /// Constructor
   /// @param condition the condition type
   /// @param conditional the condition expression
   ContinueStatement(StatementCondition condition,
diff --git a/src/ast/continue_statement_test.cc b/src/ast/continue_statement_test.cc
new file mode 100644
index 0000000..366bb4d
--- /dev/null
+++ b/src/ast/continue_statement_test.cc
@@ -0,0 +1,113 @@
+// 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/continue_statement.h"
+
+#include "gtest/gtest.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/statement_condition.h"
+
+namespace tint {
+namespace ast {
+
+using ContinueStatementTest = testing::Test;
+
+TEST_F(ContinueStatementTest, Creation) {
+  ContinueStatement stmt;
+  EXPECT_EQ(stmt.condition(), StatementCondition::kNone);
+  EXPECT_EQ(stmt.conditional(), nullptr);
+}
+
+TEST_F(ContinueStatementTest, CreationWithConditional) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  auto expr_ptr = expr.get();
+
+  ContinueStatement stmt(StatementCondition::kIf, std::move(expr));
+  EXPECT_EQ(stmt.condition(), StatementCondition::kIf);
+  EXPECT_EQ(stmt.conditional(), expr_ptr);
+}
+
+TEST_F(ContinueStatementTest, Creation_WithSource) {
+  ContinueStatement stmt(Source{20, 2});
+  auto src = stmt.source();
+  EXPECT_EQ(src.line, 20);
+  EXPECT_EQ(src.column, 2);
+}
+
+TEST_F(ContinueStatementTest, Creation_WithSourceAndCondition) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+
+  ContinueStatement stmt(Source{20, 2}, StatementCondition::kUnless,
+                         std::move(expr));
+  auto src = stmt.source();
+  EXPECT_EQ(src.line, 20);
+  EXPECT_EQ(src.column, 2);
+}
+
+TEST_F(ContinueStatementTest, IsContinue) {
+  ContinueStatement stmt;
+  EXPECT_TRUE(stmt.IsContinue());
+}
+
+TEST_F(ContinueStatementTest, IsValid_WithoutCondition) {
+  ContinueStatement stmt;
+  EXPECT_TRUE(stmt.IsValid());
+}
+
+TEST_F(ContinueStatementTest, IsValid_WithCondition) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  ContinueStatement stmt(StatementCondition::kIf, std::move(expr));
+  EXPECT_TRUE(stmt.IsValid());
+}
+
+TEST_F(ContinueStatementTest, IsValid_InvalidConditional) {
+  auto expr = std::make_unique<IdentifierExpression>("");
+  ContinueStatement stmt(StatementCondition::kIf, std::move(expr));
+  EXPECT_FALSE(stmt.IsValid());
+}
+
+TEST_F(ContinueStatementTest, IsValid_NoneConditionWithConditional) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  ContinueStatement stmt(StatementCondition::kNone, std::move(expr));
+  EXPECT_FALSE(stmt.IsValid());
+}
+
+TEST_F(ContinueStatementTest, IsValid_WithCondition_MissingConditional) {
+  ContinueStatement stmt;
+  stmt.set_condition(StatementCondition::kIf);
+  EXPECT_FALSE(stmt.IsValid());
+}
+
+TEST_F(ContinueStatementTest, ToStr_WithoutCondition) {
+  ContinueStatement stmt;
+  std::ostringstream out;
+  stmt.to_str(out, 2);
+  EXPECT_EQ(out.str(), R"(  Continue{}
+)");
+}
+
+TEST_F(ContinueStatementTest, ToStr_WithCondition) {
+  auto expr = std::make_unique<IdentifierExpression>("expr");
+  ContinueStatement stmt(StatementCondition::kUnless, std::move(expr));
+  std::ostringstream out;
+  stmt.to_str(out, 2);
+  EXPECT_EQ(out.str(), R"(  Continue{
+    unless
+    Identifier{expr}
+  }
+)");
+}
+
+}  // namespace ast
+}  // namespace tint