Initial commit

internal/server/download_test.go

@@ -0,0 +1,84 @@
+package server
+
+import (
+	"mime"
+	"strings"
+	"testing"
+)
+
+// Content-Disposition is the header that keeps an uploaded file from being
+// rendered, so it has to survive whatever a filename throws at it.
+func TestContentDisposition(t *testing.T) {
+	cases := []struct {
+		name      string
+		wantASCII string
+		wantExt   bool // expect an RFC 5987 filename* parameter too
+	}{
+		{"MyGame.zip", "MyGame.zip", false},
+		{"notes (draft).txt", "notes (draft).txt", false},
+		{`quo"te.txt`, "quo_te.txt", true},
+		{`back\slash.txt`, "back_slash.txt", true},
+		{"naïve.txt", "na_ve.txt", true},
+		{"日本語.bin", "___.bin", true},
+		{"🙂.png", "_.png", true},
+	}
+	for _, c := range cases {
+		got := contentDisposition(c.name)
+
+		// It must always parse, and always be an attachment.
+		disp, params, err := mime.ParseMediaType(got)
+		if err != nil {
+			t.Errorf("contentDisposition(%q) = %q: does not parse: %v", c.name, got, err)
+			continue
+		}
+		if disp != "attachment" {
+			t.Errorf("contentDisposition(%q): disposition = %q", c.name, disp)
+		}
+		// Whatever the encoding, the decoded filename must be the real one when
+		// an extended parameter is present.
+		if c.wantExt {
+			if !strings.Contains(got, "filename*=UTF-8''") {
+				t.Errorf("contentDisposition(%q) = %q: no RFC 5987 parameter", c.name, got)
+			}
+			if params["filename"] != c.name {
+				t.Errorf("contentDisposition(%q): decoded filename = %q", c.name, params["filename"])
+			}
+		} else if params["filename"] != c.wantASCII {
+			t.Errorf("contentDisposition(%q): filename = %q, want %q", c.name, params["filename"], c.wantASCII)
+		}
+
+		// Nothing may break out of the header, in any spelling.
+		if strings.ContainsAny(got, "\r\n") {
+			t.Errorf("contentDisposition(%q) = %q: contains a line break", c.name, got)
+		}
+		if i := strings.Index(got, `filename="`); i >= 0 {
+			quoted := got[i+len(`filename="`):]
+			quoted = quoted[:strings.Index(quoted, `"`)]
+			if strings.ContainsAny(quoted, `"\`) {
+				t.Errorf("contentDisposition(%q): unescaped quoting in %q", c.name, quoted)
+			}
+		}
+	}
+}
+
+func TestASCIIFilenameNeverEmpty(t *testing.T) {
+	for _, in := range []string{"", "...", "___", "   ", "🙂"} {
+		if got := asciiFilename(in); strings.Trim(got, "_. ") == "" {
+			t.Errorf("asciiFilename(%q) = %q, which names nothing", in, got)
+		}
+	}
+}
+
+func TestEncodeRFC5987(t *testing.T) {
+	cases := map[string]string{
+		"plain.txt": "plain.txt",
+		"a b.txt":   "a%20b.txt",
+		"naïve":     "na%C3%AFve",
+		`q"x`:       "q%22x",
+	}
+	for in, want := range cases {
+		if got := encodeRFC5987(in); got != want {
+			t.Errorf("encodeRFC5987(%q) = %q, want %q", in, got, want)
+		}
+	}
+}