Add basic ranger test

Author: jonjohnsonjr

ranger/ranger_test.go

@@ -0,0 +1,58 @@
+package ranger
+
+import (
+	"context"
+	"math/rand/v2"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+)
+
+func TestRanger(t *testing.T) {
+	s := httptest.NewServer(http.FileServerFS(os.DirFS("./testdata")))
+	defer s.Close()
+
+	uri := s.URL + "/gsip.tar"
+
+	t.Logf("uri: %q", uri)
+
+	ra := New(context.Background(), uri, s.Client().Transport)
+
+	f, err := os.Open("./testdata/gsip.tar")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+
+	info, err := f.Stat()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	size := info.Size()
+
+	// TODO: Pull this out into a test package.
+	for range 100 {
+		start := rand.Int64N(size)
+		length := rand.Int64N(size - start)
+
+		if length == 0 {
+			continue
+		}
+
+		b := make([]byte, length)
+		zb := make([]byte, length)
+
+		n, err := f.ReadAt(b, start)
+		zn, zerr := ra.ReadAt(zb, start)
+
+		if err != zerr {
+			t.Fatalf("ReadAt(%d, %d): %v != %v", start, len(b), err, zerr)
+		}
+
+		if n != zn {
+			t.Fatalf("ReadAt(%d, %d): %d != %d", start, len(b), n, zn)
+		}
+	}
+}

ranger/testdata

@@ -0,0 +1 @@
+../tarfs/testdata