1 files changed, 128 insertions, 0 deletions
diff --git a/deque_test.go b/deque_test.go
new file mode 100644
index 0000000..4f64585
--- /dev/null
+++ b/deque_test.go
@@ -0,0 +1,128 @@
+package share_test
+
+import (
+	"fmt"
+	"slices"
+	"sync"
+	"testing"
+
+	"github.com/sam-rba/share"
+)
+
+func TestDequeFIFO(t *testing.T) {
+	dq := share.NewDeque[string]()
+	vals := []string{"foo", "bar", "baz", "xyz"}
+	testFIFO(t, dq.PutTail, dq.TakeHead, vals, dq.Close)
+}
+
+func TestDequeReverseFIFO(t *testing.T) {
+	dq := share.NewDeque[string]()
+	vals := []string{"foo", "bar", "baz", "xyz"}
+	testFIFO(t, dq.PutHead, dq.TakeTail, vals, dq.Close)
+}
+
+func testFIFO[T comparable](t *testing.T, put chan<- T, take <-chan T, vals []T, end func()) {
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		produce(put, vals)
+		end()
+		wg.Done()
+	}()
+	go func() {
+		consume(t, take, vals)
+		wg.Done()
+	}()
+	wg.Wait()
+}
+
+func TestDequeLIFO(t *testing.T) {
+	dq := share.NewDeque[string]()
+	vals := []string{"foo", "bar", "baz", "xyz"}
+	testLIFO(t, dq.PutTail, dq.TakeTail, vals, dq.Close)
+}
+
+func TestDequeReverseLIFO(t *testing.T) {
+	dq := share.NewDeque[string]()
+	vals := []string{"foo", "bar", "baz", "xyz"}
+	testLIFO(t, dq.PutHead, dq.TakeHead, vals, dq.Close)
+}
+
+func testLIFO[T comparable](t *testing.T, put chan<- T, take <-chan T, vals []T, end func()) {
+	var wg sync.WaitGroup
+
+	wg.Add(1)
+	go func() {
+		produce(put, vals)
+		end()
+		wg.Done()
+	}()
+
+	want := slices.Clone(vals)
+	slices.Reverse(want)
+	wg.Wait()
+	consume(t, take, want)
+}
+
+func produce[T any](put chan<- T, vals []T) {
+	for _, v := range vals {
+		put <- v
+	}
+}
+
+func consume[T comparable](t *testing.T, take <-chan T, want []T) {
+	i := 0
+	for v := range take {
+		if i >= len(want) {
+			t.Fatal("received too many")
+		}
+		if v != want[i] {
+			t.Fatalf("Index %d: %v; want %v", i, v, want[i])
+		}
+		i++
+	}
+	if i < len(want) {
+		t.Fatalf("Only received %d; want %d", i, len(want))
+	}
+}
+
+func TestDequePutback(t *testing.T) {
+	dq := share.NewDeque[string]()
+
+	dq.PutTail <- "foo"
+	dq.PutTail <- "bar"
+	dq.PutTail <- "baz"
+	dq.PutTail <- "xyz"
+
+	<-dq.TakeHead // foo
+	<-dq.TakeHead // bar
+	<-dq.TakeHead // baz
+
+	dq.PutHead <- "baz"
+	dq.PutHead <- "bar"
+
+	dq.Close()
+
+	consume(t, dq.TakeHead, []string{"bar", "baz", "xyz"})
+}
+
+func ExampleDeque() {
+	// Use as a FIFO queue
+	dq := share.NewDeque[string]()
+
+	// Producer
+	go func() {
+		defer dq.Close()
+		for _, word := range []string{"foo", "bar", "baz"} {
+			dq.PutTail <- word
+		}
+	}()
+
+	for word := range dq.TakeHead {
+		fmt.Println(word)
+	}
+	// Output:
+	// foo
+	// bar
+	// baz
+}