govis: extend roundtrip testing

This is necessary to ensure that strings I don't have examples of work
properly. The same thing applies for double-encode and double-decode
usecases.

Signed-off-by: Aleksa Sarai <asarai@suse.de>

govis_test.go

@@ -19,36 +19,139 @@ package govis
 
 import (
 	"bytes"
+	"crypto/rand"
 	"testing"
 )
 
 const DefaultVisFlags = VisWhite | VisOctal | VisGlob
 
+func TestRandomVisUnvis(t *testing.T) {
+	// Randomly generate N strings.
+	const N = 100
+
+	for i := 0; i < N; i++ {
+		testBytes := make([]byte, 256)
+		if n, err := rand.Read(testBytes); n != cap(testBytes) || err != nil {
+			t.Fatalf("could not read enough bytes: err=%v n=%d", err, n)
+		}
+		test := string(testBytes)
+
+		for flag := VisFlag(0); flag <= visMask; flag++ {
+			// VisNoSlash is frankly just a dumb flag, and it is impossible for us
+			// to actually preserve things in a round-trip.
+			if flag&VisNoSlash == VisNoSlash {
+				continue
+			}
+
+			enc, err := Vis(test, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing vis(%q, %b): %s", test, flag, err)
+				continue
+			}
+			dec, err := Unvis(enc, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing unvis(%q, %b): %s", enc, flag, err)
+				continue
+			}
+			if dec != test {
+				t.Errorf("roundtrip failed: unvis(vis(%q, %b) = %q, %b) = %q", test, flag, enc, flag, dec)
+			}
+		}
+	}
+}
+
+func TestRandomVisVisUnvisUnvis(t *testing.T) {
+	// Randomly generate N strings.
+	const N = 100
+
+	for i := 0; i < N; i++ {
+		testBytes := make([]byte, 256)
+		if n, err := rand.Read(testBytes); n != cap(testBytes) || err != nil {
+			t.Fatalf("could not read enough bytes: err=%v n=%d", err, n)
+		}
+		test := string(testBytes)
+
+		for flag := VisFlag(0); flag <= visMask; flag++ {
+			// VisNoSlash is frankly just a dumb flag, and it is impossible for us
+			// to actually preserve things in a round-trip.
+			if flag&VisNoSlash == VisNoSlash {
+				continue
+			}
+
+			enc, err := Vis(test, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing vis(%q, %b): %s", test, flag, err)
+				continue
+			}
+			enc2, err := Vis(enc, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing vis(%q, %b): %s", enc, flag, err)
+				continue
+			}
+			dec, err := Unvis(enc2, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing unvis(%q, %b): %s", enc2, flag, err)
+				continue
+			}
+			dec2, err := Unvis(dec, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing unvis(%q, %b): %s", dec, flag, err)
+				continue
+			}
+			if dec2 != test {
+				t.Errorf("roundtrip failed: unvis(unvis(vis(vis(%q) = %q) = %q) = %q, %b) = %q", test, enc, enc2, dec, flag, dec2)
+			}
+		}
+	}
+}
+
 func TestVisUnvis(t *testing.T) {
-	// Round-trip testing.
+	for flag := VisFlag(0); flag <= visMask; flag++ {
-	for _, test := range []string{
+		// VisNoSlash is frankly just a dumb flag, and it is impossible for us
-		"",
+		// to actually preserve things in a round-trip.
-		"this.is.a.normal_string",
+		if flag&VisNoSlash == VisNoSlash {
-		"AC_Raíz_Certicámara_S.A..pem",
-		"NetLock_Arany_=Class_Gold=_Főtanúsítvány.pem",
-		"TÜBİTAK_UEKAE_Kök_Sertifika_Hizmet_Sağlayıcısı_-_Sürüm_3.pem",
-		"hello world [ this string needs=enco ding! ]",
-		"even \n more encoding necessary\a\a ",
-		"\024 <-- some more weird characters --> 你好，世界",
-		"\\xff\\n double encoding is also great fun \\x",
-	} {
-		enc, err := Vis(test, DefaultVisFlags)
-		if err != nil {
-			t.Errorf("unexpected error doing vis(%q): %s", test, err)
 			continue
 		}
-		dec, err := Unvis(enc, DefaultVisFlags)
+
-		if err != nil {
+		// Round-trip testing.
-			t.Errorf("unexpected error doing unvis(%q): %s", enc, err)
+		for _, test := range []string{
-			continue
+			"",
-		}
+			"hello world",
-		if dec != test {
+			"THIS\\IS_A_TEST1234",
-			t.Errorf("roundtrip failed: unvis(vis(%q) = %q) = %q", test, enc, dec)
+			"this.is.a.normal_string",
+			"AC_Ra\u00edz_Certic\u00e1mara_S.A..pem",
+			"NetLock_Arany_=Class_Gold=_F\u0151tan\u00fas\u00edtv\u00e1ny.pem",
+			"T\u00dcB\u0130TAK_UEKAE_K\u00f6k_Sertifika_Hizmet_Sa\u011flay\u0131c\u0131s\u0131_-_S\u00fcr\u00fcm_3.pem",
+			"hello world [ this string needs=enco ding! ]",
+			"even \n more encoding necessary\a\a ",
+			"\024 <-- some more weird characters --> \u4f60\u597d\uff0c\u4e16\u754c",
+			"\\xff\\n double encoding is also great fun \\x",
+			"AC_Ra\\M-C\\M--z_Certic\\M-C\\M-!mara_S.A..pem",
+			"z^i3i$\u00d3\u008anqgh5/t\u00e5<86>\u00b2kzla\\e^lv\u00df\u0093nv\u00df\u00aea|3}\u00d8\u0088\u00d6\u0084",
+			`z^i3i$\M-C\M^S\M-B\M^Jnqgh5/t\M-C\M-%<86>\M-B\M-2kzla\\e^lv\M-C\M^_\M-B\M^Snv\M-C\M^_\M-B\M-.a|3}\M-C\M^X\M-B\M^H\M-C\M^V\M-B\M^D`,
+			"@?e1xs+.R_Kjo]7s8pgRP:*nXCE4{!c",
+			"62_\u00c6\u00c62\u00ae\u00b7m\u00db\u00c3r^\u00bfp\u00c6u'q\u00fbc2\u00f0u\u00b8\u00dd\u00e8v\u00ff\u00b0\u00dc\u00c2\u00f53\u00db-k\u00f2sd4\\p\u00da\u00a6\u00d3\u00eea<\u00e6s{\u00a0p\u00f0\u00ffj\u00e0\u00e8\u00b8\u00b8\u00bc\u00fcb",
+			`62_\M-C\M^F\M-C\M^F2\M-B\M-.\M-B\M-7m\M-C\M^[\M-C\M^Cr^\M-B\M-?p\M-C\M^Fu'q\M-C\M-;c2\M-C\M-0u\M-B\M-8\M-C\M^]\M-C\M-(v\M-C\M-?\M-B\M-0\M-C\M^\\M-C\M^B\M-C\M-53\M-C\M^[-k\M-C\M-2sd4\\p\M-C\M^Z\M-B\M-&\M-C\M^S\M-C\M-.a<\M-C\M-&s{\M-B\240p\M-C\M-0\M-C\M-?j\M-C\240\M-C\M-(\M-B\M-8\M-B\M-8\M-B\M-<\M-C\M-<b`,
+			"\u9003\"9v1)T798|o;fly jnKX\u0489Be=",
+			`\M-i\M^@\M^C"9v1)T798|o;fly jnKX\M-R\M^IBe=`,
+			"'3Ze\u050e|\u02del\u069du-Rpct4+Z5b={@_{b",
+			`'3Ze\M-T\M^N|\M-K\M^^l\M-Z\M^]u-Rpct4+Z5b={@_{b`,
+			"1\u00c6\u00abTcz+Vda?)k1%\\\"P;`po`h",
+			`1%C3%86%C2%ABTcz+Vda%3F)k1%25%5C%22P%3B%60po%60h`,
+		} {
+			enc, err := Vis(test, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing vis(%q, %b): %s", test, flag, err)
+				continue
+			}
+			dec, err := Unvis(enc, flag)
+			if err != nil {
+				t.Errorf("unexpected error doing unvis(%q, %b): %s", enc, flag, err)
+				continue
+			}
+			if dec != test {
+				t.Errorf("roundtrip failed: unvis(vis(%q, %b) = %q, %b) = %q", test, flag, enc, flag, dec)
+			}
 		}
 	}
 }