@@ -14,12 +14,25 @@

 #include <string>

 #include <functional>

+#include <sstream>

+#include <iomanip>

+

+#include "sys_stdlib.h"

 using generator = std::function<std::string()>;

-inline generator make_generator()

+inline    std::string token_from_int(int x) {

+        int v = x % 1000000;

+        std::ostringstream is;

+        is << std::setfill('0') << std::setw(6)<< v;

+        return is.str();

+    }

+

+inline generator make_generator(const stdlib &stdlib)

 {

-    return [] {return std::string ("234567");};

+    return [stdlib] {

+        return token_from_int(stdlib.rand());

+    };

 }

 #endif

@@ -8,16 +8,40 @@

  * file. If not, you will find a copy in the "LICENSE" file

  * at https://github.com/cjdev/dual-control.

  */

-

+#include <memory>

 #include <algorithm>

-

+#include <initializer_list>

+#include <vector>

 #include "generator.h"

+#include "sys_stdlib.h"

 #include "test_util.h"

+class fake_stdlib : public stdlib_ifc {

+

+    private:

+        std::vector<int> samples_;

+        mutable std::vector<int>::iterator current_;

+    public:

+    fake_stdlib( const std::initializer_list<int> &samples)

+        : samples_(samples.begin(), samples.end()),

+          current_(samples_.begin()) {}

+    int rand() const override {

+       if (current_ != samples_.end()) {

+         auto rval = *current_;

+         current_ += 1;

+         return rval;

+       }

+       return 0;

+    }

+};

+

 int six_digits()

 {

     // given

-    generator generator = make_generator();

+    std::initializer_list<int> samples { 1, 2, 3 };

+    auto test_stdlib = std::make_shared<fake_stdlib>(samples);

+    stdlib stdlib(test_stdlib);

+    generator generator = make_generator(stdlib);

     // when

     auto actual = generator();

@@ -30,9 +54,26 @@ int six_digits()

     succeed();

 }

+int modulated_source_modulates_tokens() {

+    // given

+    std::initializer_list<int> samples { 1, 2, 3 };

+    auto test_stdlib = std::make_shared<fake_stdlib>(samples);

+    stdlib stdlib(test_stdlib);

+    generator generator = make_generator(stdlib);

+

+    // when

+    auto actual1 = generator();

+    auto actual2 = generator();

+

+    // then

+    check (actual1 != actual2, "samples should be different");

+    succeed();

+}

+

 int run_tests()

 {

     test (six_digits);

+    test (modulated_source_modulates_tokens);

     succeed();

 }