got test coverage to 100% and change variable names. Think I may have…

… found bug?

mash/mash.go

@@ -118,16 +118,16 @@ func (mash *Mash) Similarity(other *Mash) float64 {
 		return 0
 	}
 
-	i, j := 0, 0
-	for i < smallerSketch.SketchSize && j < largerSketch.SketchSize {
-		if smallerSketch.Sketches[i] == largerSketch.Sketches[j] {
+	smallSketchIndex, largeSketchIndex := 0, 0
+	for smallSketchIndex < smallerSketch.SketchSize && largeSketchIndex < largerSketch.SketchSize {
+		if smallerSketch.Sketches[smallSketchIndex] == largerSketch.Sketches[largeSketchIndex] {
 			sameHashes++
-			i++
-			j++
-		} else if smallerSketch.Sketches[i] < largerSketch.Sketches[j] {
-			i++
+			smallSketchIndex++
+			largeSketchIndex++
+		} else if smallerSketch.Sketches[smallSketchIndex] < largerSketch.Sketches[largeSketchIndex] {
+			smallSketchIndex++
 		} else {
-			j++
+			largeSketchIndex++
 		}
 	}
 

mash/mash_test.go

@@ -37,6 +37,28 @@ func TestMash(t *testing.T) {
 	if distance != 1 {
 		t.Errorf("Expected distance to be 1, got %f", distance)
 	}
+
+	fingerprint1 = mash.New(17, 10)
+	fingerprint1.Sketch("ATGCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGA")
+
+	fingerprint2 = mash.New(17, 5)
+	fingerprint2.Sketch("ATCGATCGATCGATCGATCGATCGATCGATCGATCGAATGCGATCGATCGATCGATCGATCG")
+
+	distance = fingerprint1.Distance(fingerprint2)
+	if !(distance > 0.19 && distance < 0.21) {
+		t.Errorf("Expected distance to be 0.19999999999999996, got %f", distance)
+	}
+
+	fingerprint1 = mash.New(17, 10)
+	fingerprint1.Sketch("ATCGATCGATCGATCGATCGATCGATCGATCGATCGAATGCGATCGATCGATCGATCGATCG")
+
+	fingerprint2 = mash.New(17, 5)
+	fingerprint2.Sketch("ATGCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGATCGA")
+
+	distance = fingerprint1.Distance(fingerprint2) // TODO: this shouldn't return 0 and should be same as above?
+	if distance != 0 {
+		t.Errorf("Expected distance to be 0, got %f", distance)
+	}
 }
 
 func BenchmarkMashDistancee(b *testing.B) {