test(logic): put BoundedBuffer into unit tests

x/logic/util/buffer_test.go

@@ -0,0 +1,51 @@
+package util
+
+import (
+	"fmt"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestBoundedBuffer(t *testing.T) {
+	Convey("Given test cases", t, func() {
+		tcs := []struct {
+			size       int
+			bytes      [][]byte
+			wantResult string
+		}{
+			{20, [][]byte{[]byte("hello world")}, "hello world"},
+			{11, [][]byte{[]byte("hello"), []byte(" "), []byte("world")}, "hello world"},
+			{10, [][]byte{[]byte("hello"), []byte(" "), []byte("world")}, "ello world"},
+			{5, [][]byte{[]byte("hello world")}, "world"},
+			{1, [][]byte{[]byte("hello"), []byte(" "), []byte("world")}, "d"},
+			{1, [][]byte{}, ""},
+			{0, [][]byte{[]byte("hello world")}, ""},
+		}
+
+		for tn, tc := range tcs {
+			Convey(fmt.Sprintf("Given a BoundedBuffer with size %d (%d)", tc.size, tn), func() {
+				buffer, err := NewBoundedBuffer(tc.size)
+				So(err, ShouldBeNil)
+
+				Convey("When calling the Write() function", func() {
+					wantCount := 0
+					count := 0
+					for _, b := range tc.bytes {
+						n, err := buffer.Write(b)
+						count += n
+						wantCount += len(b)
+						So(err, ShouldBeNil)
+					}
+
+					Convey("Then we should get %s", func() {
+						So(buffer.String(), ShouldEqual, tc.wantResult)
+					})
+					Convey(fmt.Sprintf("And the number of bytes written should be %d", wantCount), func() {
+						So(count, ShouldEqual, wantCount)
+					})
+				})
+			})
+		}
+	})
+}