refactoring and fixing bug.

util_test.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func makeUInt64Channel(numbers ...uint64) <-chan uint64 {
+	c := make(chan uint64)
+	go func() {
+		for _, n := range numbers {
+			c <- n
+		}
+		close(c)
+	}()
+	return c
+}
+
+func readUInt64Channel(c <-chan uint64) []uint64 {
+	ret := make([]uint64, 0)
+	for n := range c {
+		ret = append(ret, n)
+	}
+	return ret
+}
+
+func equalsAsMultiSet(a, b []uint64) bool {
+	aSet, bSet := make(map[uint64]int), make(map[uint64]int)
+	for _, e := range a {
+		if _, ok := aSet[e]; ok {
+			aSet[e]++
+		} else {
+			aSet[e] = 1
+		}
+	}
+
+	for _, e := range b {
+		if _, ok := aSet[e]; ok {
+			bSet[e]++
+		} else {
+			bSet[e] = 1
+		}
+	}
+	return reflect.DeepEqual(aSet, bSet)
+}
+
+func TestUniq(t *testing.T) {
+	c := makeUInt64Channel(1, 3, 2, 1, 4, 3, 3, 2, 1)
+	expt := []uint64{1, 3, 2, 4}
+	if ret := readUInt64Channel(uniq(c)); !reflect.DeepEqual(expt, ret) {
+		t.Fail()
+	}
+}
+
+func TestIntersection(t *testing.T) {
+	c := Intersection(makeUInt64Channel(1, 2, 3, 4), makeUInt64Channel(1, 2, 3, 4))
+	if s := readUInt64Channel(c); !equalsAsMultiSet(s, []uint64{1, 2, 3, 4}) {
+		t.Error("needed {1, 2, 3 , 4} received ", s)
+	}
+
+	c = Intersection(makeUInt64Channel(1, 2), makeUInt64Channel(1, 2, 3, 4))
+	if s := readUInt64Channel(c); !equalsAsMultiSet(s, []uint64{1, 2}) {
+		t.Error("needed {1, 2} received ", s)
+	}
+
+	c = Intersection(makeUInt64Channel(3, 4), makeUInt64Channel(1, 2, 3, 4))
+	if s := readUInt64Channel(c); !equalsAsMultiSet(s, []uint64{3, 4}) {
+		t.Error("needed {3 , 4} received ", s)
+	}
+}