src/input_stream_test.cc

// Copyright 2026 Google Inc. All Rights Reserved.
//
// 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 "input_stream.h"
#include "test.h"

namespace {

TEST(MemoryInputStreamTest, DefaultConstructor) {
  MemoryInputStream in;
  char buf[1];
  EXPECT_FALSE(in.Read(buf, 1));
  EXPECT_FALSE(in.Skip(1));
  EXPECT_TRUE(in.Skip(0));
}

TEST(MemoryInputStreamTest, Read) {
  const char data[] = "hello";
  MemoryInputStream in(data, 5);
  char buf[6];
  EXPECT_TRUE(in.Read(buf, 3));
  EXPECT_EQ(0, memcmp(buf, "hel", 3));
  EXPECT_FALSE(in.Read(buf, 3));  // Only 2 left.
  EXPECT_TRUE(in.Read(buf, 2));
  EXPECT_EQ(0, memcmp(buf, "lo", 2));
  EXPECT_FALSE(in.Read(buf, 1));
}

TEST(MemoryInputStreamTest, Skip) {
  const char data[] = "abcdef";
  MemoryInputStream in(data, 6);
  EXPECT_TRUE(in.Skip(2));
  char buf[1];
  EXPECT_TRUE(in.Read(buf, 1));
  EXPECT_EQ('c', buf[0]);
  EXPECT_FALSE(in.Skip(10));  // Should consume remainder and fail.
  EXPECT_FALSE(in.Read(buf, 1));
}

TEST(LimitedInputStreamTest, Read) {
  const char data[] = "1234567890";
  MemoryInputStream mem(data, 10);
  LimitedInputStream in(mem, 5);
  char buf[10];
  EXPECT_TRUE(in.Read(buf, 3));
  EXPECT_EQ(0, memcmp(buf, "123", 3));
  EXPECT_FALSE(in.Read(buf, 3));  // Only 2 left in limit.
  EXPECT_TRUE(in.Read(buf, 2));
  EXPECT_EQ(0, memcmp(buf, "45", 2));
  EXPECT_FALSE(in.Read(buf, 1));

  // Verify underlying stream was advanced.
  EXPECT_TRUE(mem.Read(buf, 1));
  EXPECT_EQ('6', buf[0]);
}

TEST(LimitedInputStreamTest, Skip) {
  const char data[] = "1234567890";
  MemoryInputStream mem(data, 10);
  LimitedInputStream in(mem, 5);
  EXPECT_TRUE(in.Skip(3));
  char buf[1];
  EXPECT_TRUE(in.Read(buf, 1));
  EXPECT_EQ('4', buf[0]);
  EXPECT_FALSE(in.Skip(10));  // Past limit.
  EXPECT_FALSE(in.Read(buf, 1));

  // Verify underlying stream.
  EXPECT_TRUE(mem.Read(buf, 1));
  EXPECT_EQ('6', buf[0]);
}

}  // namespace