lib/connections: Refactor address listing into connection service

lib/util/random_test.go

@@ -0,0 +1,82 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package util
+
+import (
+	"runtime"
+	"sync"
+	"testing"
+)
+
+var predictableRandomTest sync.Once
+
+func TestPredictableRandom(t *testing.T) {
+	if runtime.GOARCH != "amd64" {
+		t.Skip("Test only for 64 bit platforms; but if it works there, it should work on 32 bit")
+	}
+	predictableRandomTest.Do(func() {
+		// predictable random sequence is predictable
+		e := int64(3440579354231278675)
+		if v := int64(PredictableRandom.Int()); v != e {
+			t.Errorf("Unexpected random value %d != %d", v, e)
+		}
+	})
+}
+
+func TestSeedFromBytes(t *testing.T) {
+	// should always return the same seed for the same bytes
+	tcs := []struct {
+		bs []byte
+		v  int64
+	}{
+		{[]byte("hello world"), -3639725434188061933},
+		{[]byte("hello worlx"), -2539100776074091088},
+	}
+
+	for _, tc := range tcs {
+		if v := SeedFromBytes(tc.bs); v != tc.v {
+			t.Errorf("Unexpected seed value %d != %d", v, tc.v)
+		}
+	}
+}
+
+func TestRandomString(t *testing.T) {
+	for _, l := range []int{0, 1, 2, 3, 4, 8, 42} {
+		s := RandomString(l)
+		if len(s) != l {
+			t.Errorf("Incorrect length %d != %d", len(s), l)
+		}
+	}
+
+	strings := make([]string, 1000)
+	for i := range strings {
+		strings[i] = RandomString(8)
+		for j := range strings {
+			if i == j {
+				continue
+			}
+			if strings[i] == strings[j] {
+				t.Errorf("Repeated random string %q", strings[i])
+			}
+		}
+	}
+}
+
+func TestRandomInt64(t *testing.T) {
+	ints := make([]int64, 1000)
+	for i := range ints {
+		ints[i] = RandomInt64()
+		for j := range ints {
+			if i == j {
+				continue
+			}
+			if ints[i] == ints[j] {
+				t.Errorf("Repeated random int64 %d", ints[i])
+			}
+		}
+	}
+}