Googletest export

Introduce a new matcher for unescaping Base-64 strings to gmock.

PiperOrigin-RevId: 388471904

docs/reference/matchers.md

@@ -88,16 +88,17 @@ The `argument` can be either a C string or a C++ string object:
 
 | Matcher                 | Description                                        |
 | :---------------------- | :------------------------------------------------- |
-| `ContainsRegex(string)` | `argument` matches the given regular expression.   |
-| `EndsWith(suffix)`      | `argument` ends with string `suffix`.              |
-| `HasSubstr(string)`     | `argument` contains `string` as a sub-string.      |
-| `IsEmpty()`             | `argument` is an empty string.                     |
-| `MatchesRegex(string)`  | `argument` matches the given regular expression with the match starting at the first character and ending at the last character. |
-| `StartsWith(prefix)`    | `argument` starts with string `prefix`.            |
-| `StrCaseEq(string)`     | `argument` is equal to `string`, ignoring case.    |
-| `StrCaseNe(string)`     | `argument` is not equal to `string`, ignoring case. |
-| `StrEq(string)`         | `argument` is equal to `string`.                   |
-| `StrNe(string)`         | `argument` is not equal to `string`.               |
+| `ContainsRegex(string)`  | `argument` matches the given regular expression.  |
+| `EndsWith(suffix)`       | `argument` ends with string `suffix`.             |
+| `HasSubstr(string)`      | `argument` contains `string` as a sub-string.     |
+| `IsEmpty()`              | `argument` is an empty string.                    |
+| `MatchesRegex(string)`   | `argument` matches the given regular expression with the match starting at the first character and ending at the last character. |
+| `StartsWith(prefix)`     | `argument` starts with string `prefix`.           |
+| `StrCaseEq(string)`      | `argument` is equal to `string`, ignoring case.   |
+| `StrCaseNe(string)`      | `argument` is not equal to `string`, ignoring case. |
+| `StrEq(string)`          | `argument` is equal to `string`.                  |
+| `StrNe(string)`          | `argument` is not equal to `string`.              |
+| `WhenBase64Unescaped(m)` | `argument` is a base-64 escaped string whose unescaped string matches `m`. |
 
 `ContainsRegex()` and `MatchesRegex()` take ownership of the `RE` object. They
 use the regular expression syntax defined

googlemock/include/gmock/gmock-matchers.h

@@ -1122,6 +1122,45 @@ class EndsWithMatcher {
   const StringType suffix_;
 };
 
+// Implements the polymorphic WhenBase64Unescaped(matcher) matcher, which can be
+// used as a Matcher<T> as long as T can be converted to a string.
+class WhenBase64UnescapedMatcher {
+ public:
+  using is_gtest_matcher = void;
+
+  explicit WhenBase64UnescapedMatcher(
+      const Matcher<const std::string&>& internal_matcher)
+      : internal_matcher_(internal_matcher) {}
+
+  // Matches anything that can convert to std::string.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* listener) const {
+    const std::string s2(s);  // NOLINT (needed for working with string_view).
+    std::string unescaped;
+    if (!internal::Base64Unescape(s2, &unescaped)) {
+      if (listener != nullptr) {
+        *listener << "is not a valid base64 escaped string";
+      }
+      return false;
+    }
+    return MatchPrintAndExplain(unescaped, internal_matcher_, listener);
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "matches after Base64Unescape ";
+    internal_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "does not match after Base64Unescape ";
+    internal_matcher_.DescribeTo(os);
+  }
+
+ private:
+  const Matcher<const std::string&> internal_matcher_;
+};
+
 // Implements a matcher that compares the two fields of a 2-tuple
 // using one of the ==, <=, <, etc, operators.  The two fields being
 // compared don't have to have the same type.
@@ -4986,6 +5025,14 @@ inline internal::AddressMatcher<InnerMatcher> Address(
     const InnerMatcher& inner_matcher) {
   return internal::AddressMatcher<InnerMatcher>(inner_matcher);
 }
+
+// Matches a base64 escaped string, when the unescaped string matches the
+// internal matcher.
+template <typename MatcherType>
+internal::WhenBase64UnescapedMatcher WhenBase64Unescaped(
+    const MatcherType& internal_matcher) {
+  return internal::WhenBase64UnescapedMatcher(internal_matcher);
+}
 }  // namespace no_adl
 
 // Returns a predicate that is satisfied by anything that matches the

googlemock/include/gmock/internal/gmock-internal-utils.h

@@ -447,6 +447,8 @@ struct Function<R(Args...)> {
 template <typename R, typename... Args>
 constexpr size_t Function<R(Args...)>::ArgumentCount;
 
+bool Base64Unescape(const std::string& encoded, std::string* decoded);
+
 #ifdef _MSC_VER
 # pragma warning(pop)
 #endif

googlemock/src/gmock-internal-utils.cc

@@ -37,8 +37,14 @@
 #include "gmock/internal/gmock-internal-utils.h"
 
 #include <ctype.h>
+
+#include <array>
+#include <cctype>
+#include <cstdint>
+#include <cstring>
 #include <ostream>  // NOLINT
 #include <string>
+
 #include "gmock/gmock.h"
 #include "gmock/internal/gmock-port.h"
 #include "gtest/gtest.h"
@@ -196,5 +202,53 @@ GTEST_API_ void IllegalDoDefault(const char* file, int line) {
       "the variable in various places.");
 }
 
+constexpr char UnBase64Impl(char c, const char* const base64, char carry) {
+  return *base64 == 0   ? static_cast<char>(65)
+         : *base64 == c ? carry
+                        : UnBase64Impl(c, base64 + 1, carry + 1);
+}
+
+template <size_t... I>
+constexpr std::array<char, 256> UnBase64Impl(IndexSequence<I...>,
+                                             const char* const base64) {
+  return {UnBase64Impl(I, base64, 0)...};
+}
+
+constexpr std::array<char, 256> UnBase64(const char* const base64) {
+  return UnBase64Impl(MakeIndexSequence<256>{}, base64);
+}
+
+static constexpr char kBase64[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static constexpr std::array<char, 256> kUnBase64 = UnBase64(kBase64);
+
+bool Base64Unescape(const std::string& encoded, std::string* decoded) {
+  decoded->clear();
+  size_t encoded_len = encoded.size();
+  decoded->reserve(3 * (encoded_len / 4) + (encoded_len % 4));
+  int bit_pos = 0;
+  char dst = 0;
+  for (int src : encoded) {
+    if (std::isspace(src) || src == '=') {
+      continue;
+    }
+    char src_bin = kUnBase64[src];
+    if (src_bin >= 64) {
+      decoded->clear();
+      return false;
+    }
+    if (bit_pos == 0) {
+      dst |= src_bin << 2;
+      bit_pos = 6;
+    } else {
+      dst |= static_cast<char>(src_bin >> (bit_pos - 2));
+      decoded->push_back(dst);
+      dst = static_cast<char>(src_bin << (10 - bit_pos));
+      bit_pos = (bit_pos + 6) % 8;
+    }
+  }
+  return true;
+}
+
 }  // namespace internal
 }  // namespace testing

googlemock/test/gmock-internal-utils_test.cc

@@ -716,6 +716,46 @@ TEST(FunctionTest, LongArgumentList) {
                    F::MakeResultIgnoredValue>::value));
 }
 
+TEST(Base64Unescape, InvalidString) {
+  std::string unescaped;
+  EXPECT_FALSE(Base64Unescape("(invalid)", &unescaped));
+}
+
+TEST(Base64Unescape, ShortString) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQh", &unescaped));
+  EXPECT_EQ("Hello world!", unescaped);
+}
+
+TEST(Base64Unescape, ShortStringWithPadding) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQ=", &unescaped));
+  EXPECT_EQ("Hello world", unescaped);
+}
+
+TEST(Base64Unescape, ShortStringWithoutPadding) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQ", &unescaped));
+  EXPECT_EQ("Hello world", unescaped);
+}
+
+TEST(Base64Unescape, LongStringWithWhiteSpaces) {
+  std::string escaped =
+      R"(TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlz
+  IHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2Yg
+  dGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGlu
+  dWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRo
+  ZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=)";
+  std::string expected =
+      "Man is distinguished, not only by his reason, but by this singular "
+      "passion from other animals, which is a lust of the mind, that by a "
+      "perseverance of delight in the continued and indefatigable generation "
+      "of knowledge, exceeds the short vehemence of any carnal pleasure.";
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape(escaped, &unescaped));
+  EXPECT_EQ(expected, unescaped);
+}
+
 }  // namespace
 }  // namespace internal
 }  // namespace testing

googlemock/test/gmock-matchers_test.cc

@@ -1866,6 +1866,33 @@ TEST(EndsWithTest, CanDescribeSelf) {
   EXPECT_EQ("ends with \"Hi\"", Describe(m));
 }
 
+// Tests WhenBase64Unescaped.
+
+TEST(WhenBase64UnescapedTest, MatchesUnescapedBase64Strings) {
+  const Matcher<const char*> m1 = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m1.Matches("invalid base64"));
+  EXPECT_FALSE(m1.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m1.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+
+  const Matcher<const std::string&> m2 = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m2.Matches("invalid base64"));
+  EXPECT_FALSE(m2.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m2.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<const internal::StringView&> m3 =
+      WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m3.Matches("invalid base64"));
+  EXPECT_FALSE(m3.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m3.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(WhenBase64UnescapedTest, CanDescribeSelf) {
+  const Matcher<const char*> m = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_EQ("matches after Base64Unescape ends with \"!\"", Describe(m));
+}
+
 // Tests MatchesRegex().
 
 TEST(MatchesRegexTest, MatchesStringMatchingGivenRegex) {