Version 20.4, May 2021

[GpsPrune.git] / test / tim / prune / jpeg / drew / RationalTest.java

diff --git a/test/tim/prune/jpeg/drew/RationalTest.java b/test/tim/prune/jpeg/drew/RationalTest.java
new file mode 100644 (file)
index 0000000..ae97e0f
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+++ b/test/tim/prune/jpeg/drew/RationalTest.java
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+package tim.prune.jpeg.drew;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * JUnit tests for the Rational values used by the Exif
+ */
+class RationalTest
+{
+       @Test
+       void testManyInts()
+       {
+               testIntVal(0, 0, 0);
+               testIntVal(1, 0, 0);
+               testIntVal(0, 1, 0);
+               for (int i=0; i<16000; i++)
+               {
+                       testIntVal(0, i, 0);
+                       testIntVal(i, 0, 0);
+                       testIntVal(i, 1, i);
+                       testIntVal(-i, 1, -i);
+                       testIntVal(i*2, 2, i);
+                       testIntVal(i*2+1, 2, i);        // rounding down the 0.5
+                       testIntVal(-i*2, 2, -i);
+                       testIntVal(i*2, -2, -i);
+                       testIntVal(-i*2, -2, i);
+               }
+       }
+
+       /**
+        * Check that a rational converts to an integer properly
+        * @param inTop number on top of the rational (numerator)
+        * @param inBottom number on bottom of the rational (denominator)
+        * @param inExpected expected int value
+        */
+       private void testIntVal(long inTop, long inBottom, int inExpected)
+       {
+               Rational value = new Rational(inTop, inBottom);
+               assertEquals(inExpected, value.intValue(), "" + inTop + "/" + inBottom);
+       }
+
+       @Test
+       void testManyDoubles()
+       {
+               for (int i=0; i<16000; i++)
+               {
+                       testDoubleVal(0, i, 0.0);
+                       testDoubleVal(i, 0, 0.0);
+                       testDoubleVal(i, 1, i);
+                       testDoubleVal(i*2, 2, i);
+                       testDoubleVal(i*2+1, 2, i+0.5);
+                       testDoubleVal(i*2, -2, -i);
+               }
+
+               testDoubleVal(123, 3, 123.0/3.0);
+       }
+
+       /**
+        * Check that a rational converts to a double properly
+        * @param inTop number on top of the rational (numerator)
+        * @param inBottom number on bottom of the rational (denominator)
+        * @param inExpected expected double value (exact)
+        */
+       private void testDoubleVal(long inTop, long inBottom, double inExpected)
+       {
+               Rational value = new Rational(inTop, inBottom);
+               assertEquals(inExpected, value.doubleValue(), 0.0, "" + inTop + "/" + inBottom);
+       }
+}