Simplify stream decompressor

tools/utils/stream_decompressor_test.go

@@ -0,0 +1,36 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package utils
+
+import (
+	"bytes"
+	"compress/zlib"
+	"crypto/rand"
+	"fmt"
+	"io"
+	"testing"
+)
+
+var _ = fmt.Print
+
+func TestStreamDecompressor(t *testing.T) {
+	input := make([]byte, 9723)
+	io.ReadFull(rand.Reader, input)
+	b := bytes.Buffer{}
+	w := zlib.NewWriter(&b)
+	io.Copy(w, bytes.NewReader(input))
+	w.Close()
+	o := bytes.Buffer{}
+	sd := NewStreamDecompressor(zlib.NewReader, &o)
+	data := b.Bytes()
+	for len(data) > 0 {
+		chunk := data[:Min(117, len(data))]
+		data = data[len(chunk):]
+		if err := sd(chunk, len(data) == 0); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if !bytes.Equal(o.Bytes(), input) {
+		t.Fatalf("Roundtripping via zlib failed output (%d) != input (%d)", len(o.Bytes()), len(input))
+	}
+}