first commit

httpdl/conditional_test.go

@@ -0,0 +1,97 @@
+package httpdl
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/hanbok/got/download"
+)
+
+// TestConditionalGet304 checks that --conditional-get sends If-Modified-Since
+// for an existing local file and treats a 304 as success without rewriting the
+// file.
+func TestConditionalGet304(t *testing.T) {
+	dir := t.TempDir()
+	out := filepath.Join(dir, "file.bin")
+	const existing = "already here"
+	if err := os.WriteFile(out, []byte(existing), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	gotIfModSince := false
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("If-Modified-Since") != "" {
+			gotIfModSince = true
+		}
+		w.WriteHeader(http.StatusNotModified)
+	}))
+	defer srv.Close()
+
+	d := New([]string{srv.URL + "/file.bin"}, Config{
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		ConditionalGet:   true,
+		AllowOverwrite:   true,
+		UserAgent:        "got-test",
+	})
+	if err := d.Run(context.Background()); err != nil {
+		t.Fatalf("conditional-get 304 should succeed, got %v", err)
+	}
+	if !gotIfModSince {
+		t.Fatal("expected an If-Modified-Since header on the request")
+	}
+	if d.Stat().Status != download.Complete {
+		t.Fatalf("status = %v, want Complete", d.Stat().Status)
+	}
+	// The file must be untouched: 304 means "up to date".
+	b, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(b) != existing {
+		t.Fatalf("file was rewritten: %q, want %q", b, existing)
+	}
+}
+
+// TestConditionalGetSkippedWithControlFile verifies the rule that
+// --conditional-get is ignored when a .got control file exists, so an
+// in-progress resume is never short-circuited by a 304.
+func TestConditionalGetSkippedWithControlFile(t *testing.T) {
+	dir := t.TempDir()
+	out := filepath.Join(dir, "file.bin")
+	if err := os.WriteFile(out, []byte("partial"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	// A control file present means a resume is in flight.
+	if err := os.WriteFile(controlPath(out), []byte("{}"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	sawIfModSince := false
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("If-Modified-Since") != "" {
+			sawIfModSince = true
+		}
+		// Serve a small body so the run can complete.
+		http.Error(w, "no range", http.StatusOK)
+	}))
+	defer srv.Close()
+
+	d := New([]string{srv.URL + "/file.bin"}, Config{
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		ConditionalGet:   true,
+		AllowOverwrite:   true,
+		UserAgent:        "got-test",
+	})
+	_ = d.Run(context.Background())
+	if sawIfModSince {
+		t.Fatal("If-Modified-Since must not be sent when a control file exists")
+	}
+}