Improve response time by only looking at top-N items

1 files changed, 80 insertions, 0 deletions

diff --git a/src/merger_test.go b/src/merger_test.go
new file mode 100644
index 00000000..19941b17
--- /dev/null
+++ b/src/merger_test.go
@@ -0,0 +1,80 @@
+package fzf
+
+import (
+	"math/rand"
+	"sort"
+	"testing"
+)
+
+func assert(t *testing.T, cond bool, msg ...string) {
+	if !cond {
+		t.Error(msg)
+	}
+}
+
+func randItem() *Item {
+	return &Item{
+		rank: Rank{uint16(rand.Uint32()), uint16(rand.Uint32()), rand.Uint32()}}
+}
+
+func TestEmptyMerger(t *testing.T) {
+	assert(t, EmptyMerger.Length() == 0, "Not empty")
+}
+
+func buildLists(partiallySorted bool) ([][]*Item, []*Item) {
+	numLists := 4
+	lists := make([][]*Item, numLists)
+	cnt := 0
+	for i := 0; i < numLists; i++ {
+		numItems := rand.Int() % 20
+		cnt += numItems
+		lists[i] = make([]*Item, numItems)
+		for j := 0; j < numItems; j++ {
+			item := randItem()
+			lists[i][j] = item
+		}
+		if partiallySorted {
+			sort.Sort(ByRelevance(lists[i]))
+		}
+	}
+	items := []*Item{}
+	for _, list := range lists {
+		items = append(items, list...)
+	}
+	return lists, items
+}
+
+func TestMergerUnsorted(t *testing.T) {
+	lists, items := buildLists(false)
+	cnt := len(items)
+
+	// Not sorted: same order
+	mg := NewMerger(lists, false)
+	assert(t, cnt == mg.Length(), "Invalid Length")
+	for i := 0; i < cnt; i++ {
+		assert(t, items[i] == mg.Get(i), "Invalid Get")
+	}
+}
+
+func TestMergerSorted(t *testing.T) {
+	lists, items := buildLists(true)
+	cnt := len(items)
+
+	// Sorted sorted order
+	mg := NewMerger(lists, true)
+	assert(t, cnt == mg.Length(), "Invalid Length")
+	sort.Sort(ByRelevance(items))
+	for i := 0; i < cnt; i++ {
+		if items[i] != mg.Get(i) {
+			t.Error("Not sorted", items[i], mg.Get(i))
+		}
+	}
+
+	// Inverse order
+	mg2 := NewMerger(lists, true)
+	for i := cnt - 1; i >= cnt; i-- {
+		if items[i] != mg2.Get(i) {
+			t.Error("Not sorted", items[i], mg2.Get(i))
+		}
+	}
+}