🚧 Add Defrag function

blocks_test.go

@@ -0,0 +1,31 @@
+package defrag
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type tt struct {
+	name      string
+	diskMap   []byte
+	blocks    []byte
+	defragged []byte
+}
+
+func sampleTests() []tt {
+	return []tt{
+		{"short", []byte("12345"), []byte("0..111....22222"), []byte("022111222......")},
+		{"longer", []byte("2333133121414131402"), []byte("00...111...2...333.44.5555.6666.777.888899"), []byte("0099811188827773336446555566..............")},
+	}
+}
+
+func TestBlocks(t *testing.T) {
+	for _, testcase := range sampleTests() {
+		t.Run(testcase.name, func(sub *testing.T) {
+			blocks, err := Blocks(testcase.diskMap)
+			require.NoError(sub, err)
+			require.Equal(sub, testcase.blocks, blocks)
+		})
+	}
+}