feat: Added nanoId support (#973)

* generate nano id

* tests

* done

* changed function name

* split tests

include/faker-cxx/string.h

@@ -299,4 +299,55 @@ FAKER_CXX_EXPORT std::string numeric(unsigned length = 1, bool allowLeadingZeros
  * @endcode
  */
 FAKER_CXX_EXPORT std::string numeric(GuaranteeMap&& guarantee, unsigned length = 1, bool allowLeadingZeros = true);
-}
+
+/**
+ * @brief Generates a unique, URL-safe string identifier of the specified length.
+ *
+ * This function generates a unique identifier using a cryptographically secure
+ * random number generator, with the output length set by the `length` parameter.
+ *
+ * @param length The exact length of the identifier to generate.
+ *
+ * @returns A unique, URL-safe string identifier of the specified length.
+ *
+ * @code
+ * nanoId(10); // Possible output: "F8aXz1Q4wB"
+ * nanoId(21); // Possible output: "V2JlO7GZ1kPl9FxErRqzS"
+ * @endcode
+ */
+FAKER_CXX_EXPORT std::string nanoId(int length);
+
+/**
+ * @brief Generates a unique, URL-safe string identifier of default length.
+ *
+ * This function generates a unique identifier with a default length of 10 characters.
+ * The identifier is URL-safe and created using a cryptographically secure
+ * random number generator.
+ *
+ * @returns A unique, URL-safe string identifier of default length (10 characters).
+ *
+ * @code
+ * nanoId(); // Possible output: "Hf5lN8L2wQ"
+ * @endcode
+ */
+FAKER_CXX_EXPORT std::string nanoId();
+
+/**
+ * @brief Generates a unique, URL-safe string identifier of random length within a specified range.
+ *
+ * This function generates a unique identifier with a length that varies between
+ * `minLength` and `maxLength`, inclusive. The identifier is URL-safe and created
+ * using a cryptographically secure random number generator.
+ *
+ * @param minLength The minimum length of the identifier.
+ * @param maxLength The maximum length of the identifier.
+ *
+ * @returns A unique, URL-safe string identifier with a length between `minLength` and `maxLength`.
+ *
+ * @code
+ * nanoId(10, 15); // Possible output: "Vb2Ej8G9wPcQ2"
+ * nanoId(5, 8);   // Possible output: "P1zZ3x"
+ * @endcode
+ */
+FAKER_CXX_EXPORT std::string nanoId(int minLength, int maxLength);
+}

src/modules/string.cpp

@@ -2,6 +2,7 @@
 
 #include <cassert>
 #include <map>
+#include <random>
 #include <set>
 #include <stdexcept>
 #include <string>
@@ -300,4 +301,62 @@ std::string numeric(GuaranteeMap&& guarantee, unsigned length, bool allowLeading
         return firstChar + generateStringWithGuarantee(guarantee, targetCharacters, length - 1);
     }
 }
+
+std::string nanoId(int length)
+{
+
+    if (length < 1)
+        return "";
+
+    std::random_device rd;
+    std::mt19937 generator(rd());
+    std::uniform_int_distribution<int> distribution(0, nanoIdAllowedCharacters.size() - 1);
+
+    std::string id;
+    for (size_t i = 0; i < length; ++i)
+    {
+        id += nanoIdAllowedCharacters[distribution(generator)];
+    }
+
+    return id;
+}
+
+std::string nanoId()
+{
+    std::random_device rd;
+    std::mt19937 generator(rd());
+    std::uniform_int_distribution<int> distribution(0, nanoIdAllowedCharacters.size() - 1);
+
+    std::string id;
+    for (size_t i = 0; i < 10; ++i)
+    {
+        id += nanoIdAllowedCharacters[distribution(generator)];
+    }
+
+    return id;
+}
+
+std::string nanoId(int minLength, int maxLength)
+{
+    if (maxLength - minLength < 1)
+        return "";
+
+    std::random_device rd;
+    std::mt19937 generator(rd());
+
+    std::uniform_int_distribution<int> lengthDistribution(minLength, maxLength);
+    int length = lengthDistribution(generator);
+
+    std::uniform_int_distribution<int> charDistribution(0, nanoIdAllowedCharacters.size() - 1);
+
+    std::string id;
+    for (size_t i = 0; i < length; ++i)
+    {
+        id += nanoIdAllowedCharacters[charDistribution(generator)];
+    }
+
+    return id;
+}
+
+
 }

src/modules/string_data.h

@@ -14,6 +14,7 @@ const std::string lowerAlphanumericCharacters{lowerCharacters + numericCharacter
 const std::string upperAlphanumericCharacters{upperCharacters + numericCharacters};
 const std::string mixedAlphanumericCharacters{upperCharacters + lowerCharacters + numericCharacters};
 const std::string symbolCharacters{"~`!@#$%^&*()_-+={[}]|:;\"'<,>.?/"};
+const std::string nanoIdAllowedCharacters{mixedAlphanumericCharacters + "_-"};
 
 const std::set<char> lowerCharSet{
     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',

tests/modules/string_test.cpp

@@ -923,3 +923,24 @@ TEST_F(StringTest, invalidGuaranteeForNumeric4)
     GuaranteeMap guarantee = {{'0', {5}}};
     ASSERT_THROW(numeric(std::move(guarantee), numericLength, false), std::invalid_argument);
 }
+
+TEST_F(StringTest, shouldGenerateNanoIdWithSpecificLength)
+{
+    ASSERT_EQ(nanoId(20).size(), 20);
+    ASSERT_EQ(nanoId(0).size(), 0);
+    ASSERT_EQ(nanoId(-1).size(), 0);
+}
+
+TEST_F(StringTest, shouldGenerateNanoIdWithDefaultLength)
+{
+    ASSERT_EQ(nanoId().size(), 10);
+}
+
+TEST_F(StringTest, shouldGenerateNanoIdWithLengthFromRange)
+{
+    ASSERT_EQ(nanoId(8, 2).size(), 0);
+
+    const auto rangeNanoid = nanoId(2, 8);
+    ASSERT_GE(rangeNanoid.size(), 2);
+    ASSERT_LE(rangeNanoid.size(), 8);
+}