first commit

sorting/streams_test.go

@@ -0,0 +1,140 @@
+package sorting
+
+import (
+	"reflect"
+	"testing"
+)
+
+type MockIsGreaterer int
+
+func (i MockIsGreaterer) IsGreater(e IsGreaterer) bool {
+	return i > e.(MockIsGreaterer)
+}
+
+func streamEqual(stream Stream, expected ...int) bool {
+	i := 0
+	for v := range stream {
+		if i >= len(expected) {
+			return false
+		}
+		if MockIsGreaterer(expected[i]) != v {
+			return false
+		}
+		i++
+	}
+	return i == len(expected)
+
+}
+
+func CreateStream(values ...int) Stream {
+	s := make(Stream)
+	go func() {
+		for _, val := range values {
+			s <- MockIsGreaterer(val)
+		}
+		close(s)
+	}()
+
+	return s
+}
+
+func TestReadFirstElementOfAllTheStreams(t *testing.T) {
+	s1 := CreateStream(0, 1)
+	arr := readFirstElementOfAllTheStreams([]Stream{s1})
+	if !reflect.DeepEqual(arr, []IsGreaterer{MockIsGreaterer(0)}) {
+		t.Error(arr)
+	}
+
+	if next := <-s1; next != MockIsGreaterer(1) {
+		t.Error("read too many element in the list")
+		return
+	}
+
+	s1 = CreateStream(0, 1, 2)
+	s2 := CreateStream(5, 6, 7)
+	s3 := CreateStream(90, 91, 92)
+	arr = readFirstElementOfAllTheStreams([]Stream{s1, s2, s3})
+	if !reflect.DeepEqual(arr, []IsGreaterer{MockIsGreaterer(0), MockIsGreaterer(5), MockIsGreaterer(90)}) {
+		t.Error(arr)
+	}
+}
+
+func TestAllStreamsButOne(t *testing.T) {
+	streams := []Stream{CreateStream(0, 10, 1), CreateStream(1, 10, 1), CreateStream(2, 10, 1)}
+
+	res := allStreamsButOne(streams, 1)
+	if len(res) != 2 {
+		t.Error()
+	}
+	if e := <-res[0]; e != MockIsGreaterer(0) {
+		t.Error()
+	}
+	if e := <-res[1]; e != MockIsGreaterer(2) {
+		t.Error()
+	}
+}
+
+func TestGetSmallerStreamWithSecondSmallestElementWithAllTheOthersGreaterStreams(t *testing.T) {
+	streams := []Stream{CreateStream(0, 1), CreateStream(3, 4), CreateStream(7, 8)}
+	stream, e, streams := getSmallerStreamWithSecondSmallestElementWithAllTheOthersGreaterStreams(streams)
+	var _ = stream
+	_ = streams
+	if e != MockIsGreaterer(3) {
+		t.Error("getSmallerStreamWithSecondSmallestElementWithAllTheOthersGreaterStreams does not return the second smallest value", e)
+	}
+
+	if v := <-stream; v != MockIsGreaterer(0) {
+		t.Error("return streams is not the smalest", v)
+	}
+
+	if len(streams) != 2 {
+		t.Error("bad number of returned streams")
+	}
+
+	if len(streams) != 2 {
+		t.Error("bad number of returned streams")
+	}
+}
+
+func TestSortStreams(t *testing.T) {
+	if s := SortStreams(CreateStream(0, 1, 2)); !streamEqual(s, 0, 1, 2) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(0, 1), CreateStream(2, 3)); !streamEqual(s, 0, 1, 2, 3) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(0), CreateStream(2)); !streamEqual(s, 0, 2) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(0, 5), CreateStream(2)); !streamEqual(s, 0, 2, 5) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(0, 5), CreateStream(2, 7)); !streamEqual(s, 0, 2, 5, 7) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(0, 5), CreateStream(2, 7, 9, 10, 12)); !streamEqual(s, 0, 2, 5, 7, 9, 10, 12) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(), CreateStream(2, 7)); !streamEqual(s, 2, 7) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(), CreateStream(2, 7), CreateStream(3, 8)); !streamEqual(s, 2, 3, 7, 8) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream()); !streamEqual(s) {
+		t.Error()
+	}
+
+	if s := SortStreams(CreateStream(1, 2), CreateStream(2, 3)); !streamEqual(s, 1, 2, 2, 3) {
+		t.Error()
+	}
+
+}