// 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 "gtest/gtest.h"
#include "src/ast/function.h"
#include "src/ast/type/type.h"
#include "src/reader/wgsl/parser_impl.h"

namespace tint {
namespace reader {
namespace wgsl {

using ParserImplTest = testing::Test;

TEST_F(ParserImplTest, FunctionDecl) {
  ParserImpl p{"fn main(a : i32, b : f32) -> void { return; }"};
  auto f = p.function_decl();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_NE(f, nullptr);

  EXPECT_EQ(f->name(), "main");
  ASSERT_NE(f->return_type(), nullptr);
  EXPECT_TRUE(f->return_type()->IsVoid());

  ASSERT_EQ(f->params().size(), 2);
  EXPECT_EQ(f->params()[0]->name(), "a");
  EXPECT_EQ(f->params()[1]->name(), "b");

  ASSERT_NE(f->return_type(), nullptr);
  EXPECT_TRUE(f->return_type()->IsVoid());

  ASSERT_EQ(f->body().size(), 1);
  EXPECT_TRUE(f->body()[0]->IsReturn());
}

TEST_F(ParserImplTest, FunctionDecl_InvalidHeader) {
  ParserImpl p{"fn main() -> { }"};
  auto f = p.function_decl();
  ASSERT_TRUE(p.has_error());
  ASSERT_EQ(f, nullptr);
  EXPECT_EQ(p.error(), "1:14: unable to determine function return type");
}

TEST_F(ParserImplTest, FunctionDecl_InvalidBody) {
  ParserImpl p{"fn main() -> void { return }"};
  auto f = p.function_decl();
  ASSERT_TRUE(p.has_error());
  ASSERT_EQ(f, nullptr);
  EXPECT_EQ(p.error(), "1:28: missing ;");
}

}  // namespace wgsl
}  // namespace reader
}  // namespace tint