[poincare] Add tests on Helpers::Rotate

poincare/Makefile

@@ -141,6 +141,7 @@ tests += $(addprefix poincare/test/,\
   fraction_layout.cpp\
   function.cpp\
   helper.cpp\
+  helpers.cpp\
   integer.cpp\
   layouts.cpp\
   logarithm.cpp\

poincare/test/helpers.cpp

@@ -0,0 +1,112 @@
+#include <quiz.h>
+#include <assert.h>
+#include <iostream>
+
+#include <poincare/helpers.h>
+#include "helper.h"
+
+static inline void assert_gcd_is(size_t a, size_t b, size_t g) {
+  quiz_assert(Poincare::Helpers::Gcd(a, b) == g);
+}
+
+QUIZ_CASE(poincare_helpers_gcd) {
+  assert_gcd_is(1, 1, 1);
+  assert_gcd_is(2, 3, 1);
+  assert_gcd_is(7, 5, 1);
+  assert_gcd_is(3, 9, 3);
+}
+
+QUIZ_CASE(poincare_helpers_insert_simple_swap) {
+  constexpr size_t bufSize = 3;
+  uint32_t buf[bufSize];
+  for (size_t i = 0; i < bufSize; i++) {
+    buf[i] = (uint32_t) i;
+  }
+
+  Poincare::Helpers::Rotate(&buf[0], &buf[1], 1);
+  assert(buf[0] == 1);
+  assert(buf[1] == 0);
+  assert(buf[2] == 2);
+
+  Poincare::Helpers::Rotate(&buf[2], &buf[0], 1);
+  assert(buf[0] == 0);
+  assert(buf[1] == 1);
+  assert(buf[2] == 2);
+}
+
+static inline void test_rotate(uint32_t buf[], size_t bufSize, size_t dstIndex, size_t srcIndex, size_t len) {
+  quiz_assert(len == 0 || (srcIndex + len - 1 < bufSize));
+
+  Poincare::Helpers::Rotate(&buf[dstIndex], &buf[srcIndex], len);
+
+  if (len == 0 || srcIndex == dstIndex || (dstIndex > srcIndex && dstIndex < srcIndex + len)) {
+    for (size_t i = 0; i < bufSize; i++) {
+      quiz_assert(buf[i] == i);
+    }
+  } else if (dstIndex < srcIndex) {
+    /* Typical case:
+     *
+     * | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
+     *         ^¨¨¨¨¨¨¨^---^
+     *        Dst       Src       Len = 1
+     *
+     * After rotation:
+     * | 0 | 1 | 4 | 2 | 3 | 5 | 6 |
+     *          --- ¨¨¨¨¨¨¨
+     * */
+    for (size_t i = 0; i < dstIndex; i++) {
+      quiz_assert(buf[i] == i);
+    }
+    for (size_t i = dstIndex; i < dstIndex + len; i++) {
+      quiz_assert(buf[i] == srcIndex + (i - dstIndex));
+    }
+    for (size_t i = dstIndex + len; i < srcIndex + len; i++) {
+      quiz_assert(buf[i] == dstIndex + (i - (dstIndex + len)));
+    }
+    for (size_t i = srcIndex + len; i < bufSize; i++) {
+      quiz_assert(buf[i] == i);
+    }
+  } else {
+    /* Typical case:
+     *
+     * | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
+     *         ^-------^¨¨¨^
+     *         Src        Dst       Len = 2
+     *
+     * After rotation:
+     * | 0 | 1 | 4 | 2 | 3 | 5 | 6 |
+     *          ¨¨¨ -------
+     * */
+    for (size_t i = 0; i < srcIndex; i++) {
+      quiz_assert(buf[i] == i);
+    }
+    size_t srcDataNewPosition = srcIndex + dstIndex - (srcIndex + len);
+    for (size_t i = srcIndex; i < srcDataNewPosition; i++) {
+      quiz_assert(buf[i] == i + len);
+    }
+    for (size_t i = srcDataNewPosition; i < dstIndex; i++) {
+      quiz_assert(buf[i] == srcIndex + i - srcDataNewPosition);
+    }
+    for (size_t i = dstIndex; i < bufSize; i++) {
+      quiz_assert(buf[i] == i);
+    }
+  }
+}
+
+QUIZ_CASE(poincare_helpers_rotate) {
+  // We test all dst, src and len combinations for a buffer of size 100
+  constexpr size_t bufSize = 100;
+  uint32_t buf[bufSize];
+  for (size_t dst = 0; dst < bufSize; dst++) {
+    for (size_t src = 0; src < bufSize; src++) {
+      for (size_t len = 0; len < bufSize - src + 1; len++) {
+        // Reset the start buffer
+        for (size_t i = 0; i < bufSize; i++) {
+          buf[i] = (uint32_t) i;
+        }
+        // Launch the test
+        test_rotate(buf, bufSize, dst, src, len);
+      }
+    }
+  }
+}