Contribute yield function

Author: dolfandringa

src/FunctionFake.cpp

@@ -115,3 +115,8 @@ long map(long value, long fromLow, long fromHigh, long toLow, long toHigh)
 {
     return ArduinoFakeInstance(Function)->map(value, fromLow, fromHigh, toLow, toHigh);
 }
+
+void yield()
+{
+    ArduinoFakeInstance(Function)->yield();
+}

src/FunctionFake.h

@@ -41,4 +41,6 @@ struct FunctionFake
     virtual void randomSeed(unsigned long) = 0;
 
     virtual long map(long, long, long, long, long) = 0;
+
+    virtual void yield() = 0;
 };

src/arduino/Arduino.h

@@ -127,6 +127,8 @@ typedef uint8_t byte;
 void init(void);
 void initVariant(void);
 
+void yield(void);
+
 int atexit(void (*func)()) __attribute__((weak));
 
 void pinMode(uint8_t, uint8_t);

test/test_function.h

@@ -49,6 +49,15 @@ namespace FunctionTest
         Verify(Method(ArduinoFake(), analogRead).Using(4)).Once();
     }
 
+    void test_yield(void)
+    {
+        When(Method(ArduinoFake(), yield)).AlwaysReturn();
+
+        yield();
+
+        Verify(Method(ArduinoFake(), yield)).Once();
+    }
+
     void test_delay(void)
     {
         When(Method(ArduinoFake(), delay)).AlwaysReturn();