Fix get-last index out of bounds issue

Informaticore · Apr 5, 2024 · 3b2ef66 · 3b2ef66
1 parent 77262a4
commit 3b2ef66
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/src/ringbuffer.toit b/src/ringbuffer.toit
@@ -48,4 +48,4 @@ class RingBuffer:
     return math.sqrt variance / size_
 
   get_last -> float:
-    return buffer[head - 1]
+    return buffer[(head - 1 + size_) % size_]
diff --git a/test/test_ringbuffer.toit b/test/test_ringbuffer.toit
@@ -15,6 +15,7 @@ class TestRingbuffer implements TestCase:
     test_ringbuffer_max
     test_ringbuffer_limit
     test_ringbuffer_get_last
+    test_ringbuffer_get_last_when_full
     test_ringbuffer_std_deviation
 
   name -> string:
@@ -105,6 +106,13 @@ class TestRingbuffer implements TestCase:
     last = ringbuffer.get_last
     assertEquals 2.0 last
 
+  test_ringbuffer_get_last_when_full:
+    ringbuffer := RingBuffer 5
+    5.repeat:
+      ringbuffer.append (it + 1).to-float
+    last := ringbuffer.get_last
+    assertEquals 5.0 last
+
   test_ringbuffer_std_deviation:
     ringbuffer := RingBuffer 5