carbon-lang/toolchain/lexer/token_kind_test.cpp

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#include "toolchain/lexer/token_kind.h"

#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include <cstring>

#include "llvm/ADT/StringRef.h"

namespace Carbon::Testing {
namespace {

using ::testing::MatchesRegex;

// We restrict symbols to punctuation characters that are expected to be widely
// available on modern keyboards used for programming.
constexpr llvm::StringLiteral SymbolRegex =
    R"([\[\]{}!@#%^&*()/?\\|;:.,<>=+~-]+)";

// We restrict keywords to be lowercase ASCII letters and underscores.
constexpr llvm::StringLiteral KeywordRegex = "[a-z_]+";

#define CARBON_TOKEN(TokenName)                               \
  TEST(TokenKindTest, TokenName) {                            \
    EXPECT_EQ(#TokenName, TokenKind::TokenName().Name());     \
    EXPECT_FALSE(TokenKind::TokenName().IsSymbol());          \
    EXPECT_FALSE(TokenKind::TokenName().IsKeyword());         \
    EXPECT_EQ("", TokenKind::TokenName().GetFixedSpelling()); \
  }
#define CARBON_SYMBOL_TOKEN(TokenName, Spelling)                    \
  TEST(TokenKindTest, TokenName) {                                  \
    EXPECT_EQ(#TokenName, TokenKind::TokenName().Name());           \
    EXPECT_TRUE(TokenKind::TokenName().IsSymbol());                 \
    EXPECT_FALSE(TokenKind::TokenName().IsGroupingSymbol());        \
    EXPECT_FALSE(TokenKind::TokenName().IsOpeningSymbol());         \
    EXPECT_FALSE(TokenKind::TokenName().IsClosingSymbol());         \
    EXPECT_FALSE(TokenKind::TokenName().IsKeyword());               \
    EXPECT_EQ(Spelling, TokenKind::TokenName().GetFixedSpelling()); \
    EXPECT_THAT(Spelling, MatchesRegex(SymbolRegex.str()));         \
  }
#define CARBON_OPENING_GROUP_SYMBOL_TOKEN(TokenName, Spelling, ClosingName) \
  TEST(TokenKindTest, TokenName) {                                          \
    EXPECT_EQ(#TokenName, TokenKind::TokenName().Name());                   \
    EXPECT_TRUE(TokenKind::TokenName().IsSymbol());                         \
    EXPECT_TRUE(TokenKind::TokenName().IsGroupingSymbol());                 \
    EXPECT_TRUE(TokenKind::TokenName().IsOpeningSymbol());                  \
    EXPECT_EQ(TokenKind::ClosingName(),                                     \
              TokenKind::TokenName().GetClosingSymbol());                   \
    EXPECT_FALSE(TokenKind::TokenName().IsClosingSymbol());                 \
    EXPECT_FALSE(TokenKind::TokenName().IsKeyword());                       \
    EXPECT_EQ(Spelling, TokenKind::TokenName().GetFixedSpelling());         \
    EXPECT_THAT(Spelling, MatchesRegex(SymbolRegex.str()));                 \
  }
#define CARBON_CLOSING_GROUP_SYMBOL_TOKEN(TokenName, Spelling, OpeningName) \
  TEST(TokenKindTest, TokenName) {                                          \
    EXPECT_EQ(#TokenName, TokenKind::TokenName().Name());                   \
    EXPECT_TRUE(TokenKind::TokenName().IsSymbol());                         \
    EXPECT_TRUE(TokenKind::TokenName().IsGroupingSymbol());                 \
    EXPECT_FALSE(TokenKind::TokenName().IsOpeningSymbol());                 \
    EXPECT_TRUE(TokenKind::TokenName().IsClosingSymbol());                  \
    EXPECT_EQ(TokenKind::OpeningName(),                                     \
              TokenKind::TokenName().GetOpeningSymbol());                   \
    EXPECT_FALSE(TokenKind::TokenName().IsKeyword());                       \
    EXPECT_EQ(Spelling, TokenKind::TokenName().GetFixedSpelling());         \
    EXPECT_THAT(Spelling, MatchesRegex(SymbolRegex.str()));                 \
  }
#define CARBON_KEYWORD_TOKEN(TokenName, Spelling)                   \
  TEST(TokenKindTest, TokenName) {                                  \
    EXPECT_EQ(#TokenName, TokenKind::TokenName().Name());           \
    EXPECT_FALSE(TokenKind::TokenName().IsSymbol());                \
    EXPECT_TRUE(TokenKind::TokenName().IsKeyword());                \
    EXPECT_EQ(Spelling, TokenKind::TokenName().GetFixedSpelling()); \
    EXPECT_THAT(Spelling, MatchesRegex(KeywordRegex.str()));        \
  }
#include "toolchain/lexer/token_registry.def"

// Verify that the symbol tokens are sorted from longest to shortest. This is
// important to ensure that simply in-order testing will identify tokens
// following the max-munch rule.
TEST(TokenKindTest, SymbolsInDescendingLength) {
  int previous_length = INT_MAX;
#define CARBON_SYMBOL_TOKEN(TokenName, Spelling)                        \
  EXPECT_LE(llvm::StringRef(Spelling).size(), previous_length)          \
      << "Symbol token not in descending length order: " << #TokenName; \
  previous_length = llvm::StringRef(Spelling).size();
#include "toolchain/lexer/token_registry.def"
  EXPECT_GT(previous_length, 0);
}

}  // namespace
}  // namespace Carbon::Testing