seekbuf: add test file

seekbuf/seekbuf_test.go

@@ -0,0 +1,39 @@
+package seekbuf
+
+import (
+	"fmt"
+	"testing"
+
+	"git.wntrmute.dev/kyle/goutils/assert"
+)
+
+func TestSeeking(t *testing.T) {
+	partA := []byte("hello, ")
+	partB := []byte("world!")
+
+	buf := New(partA)
+	assert.BoolT(t, buf.Len() == len(partA), fmt.Sprintf("on init: have length %d, want length %d", buf.Len(), len(partA)))
+
+	b := make([]byte, 32)
+
+	n, err := buf.Read(b)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, buf.Len() == 0, fmt.Sprintf("after reading 1: have length %d, want length 0", buf.Len()))
+	assert.BoolT(t, n == len(partA), fmt.Sprintf("after reading 2: have length %d, want length %d", n, len(partA)))
+
+	n, err = buf.Write(partB)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, n == len(partB), fmt.Sprintf("after writing: have length %d, want length %d", n, len(partB)))
+
+	n, err = buf.Read(b)
+	assert.NoErrorT(t, err)
+	assert.BoolT(t, buf.Len() == 0, fmt.Sprintf("after rereading 1: have length %d, want length 0", buf.Len()))
+	assert.BoolT(t, n == len(partB), fmt.Sprintf("after rereading 2: have length %d, want length %d", n, len(partB)))
+
+	partsLen := len(partA) + len(partB)
+	buf.Rewind()
+	assert.BoolT(t, buf.Len() == partsLen, fmt.Sprintf("after rewinding: have length %d, want length %d", buf.Len(), partsLen))
+
+	buf.Close()
+	assert.BoolT(t, buf.Len() == 0, fmt.Sprintf("after closing, have length %d, want length 0", buf.Len()))
+}