fix tests

rand.go

@@ -4,7 +4,6 @@
 package rand
 
 import (
-	"math"
 	"math/bits"
 	"runtime"
 	"sync/atomic"
@@ -14,7 +13,7 @@ import (
 
 // Int32 returns a tread-safe, non-cryptographic pseudorandom int32.
 func Int32() int32 {
-	return int32(xxhash32(uint32(next()), 0))
+	return int32(xxhash32(uint32(next()), 0) >> 1)
 }
 
 // Int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n)
@@ -41,7 +40,7 @@ func Uint32n(maxN uint32) uint32 {
 
 // Int63 returns a non-negative pseudo-random 63-bit integer as an int64
 func Int63() int64 {
-	return int64(xxhash64(next(), 0))
+	return int64(xxhash64(next(), 0) >> 1)
 }
 
 // Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n <= 0.
@@ -84,12 +83,22 @@ func Bool() bool {
 
 // Float32 returns, as a float32, a pseudo-random number in [0.0,1.0)
 func Float32() float32 {
-	return math.Float32frombits(Uint32()) / (1 << 31)
+again: // Source: math/rand. Copyright 2009 The Go Authors.
+	f := float32(Float64())
+	if f == 1 {
+		goto again
+	}
+	return f
 }
 
-// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0)
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0).
 func Float64() float64 {
-	return math.Float64frombits(Uint64()) / (1 << 63)
+again: // Source: math/rand. Copyright 2009 The Go Authors.
+	f := float64(Int63()) / (1 << 63)
+	if f == 1 {
+		goto again
+	}
+	return f
 }
 
 // --------------------------------- Hashing ---------------------------------

rand_test.go

@@ -94,8 +94,9 @@ func TestInt32(t *testing.T) {
 	m := make(map[int32]struct{})
 	for i := 0; i < 1e3; i++ {
 		n := Int32()
+		assert.GreaterOrEqual(t, n, int32(0))
 		if _, ok := m[n]; ok {
-			t.Fatalf("number %v already exists", n)
+			assert.Fail(t, "number %v already exists", n)
 		}
 		m[n] = struct{}{}
 	}
@@ -105,8 +106,9 @@ func TestInt63(t *testing.T) {
 	m := make(map[int64]struct{})
 	for i := 0; i < 1e3; i++ {
 		n := Int63()
+		assert.GreaterOrEqual(t, n, int64(0))
 		if _, ok := m[n]; ok {
-			t.Fatalf("number %v already exists", n)
+			assert.Fail(t, "number %v already exists", n)
 		}
 		m[n] = struct{}{}
 	}
@@ -117,7 +119,7 @@ func TestUint32(t *testing.T) {
 	for i := 0; i < 1e3; i++ {
 		n := Uint32()
 		if _, ok := m[n]; ok {
-			t.Fatalf("number %v already exists", n)
+			assert.Fail(t, "number %v already exists", n)
 		}
 		m[n] = struct{}{}
 	}
@@ -128,7 +130,7 @@ func TestUint64(t *testing.T) {
 	for i := 0; i < 1e3; i++ {
 		n := Uint64()
 		if _, ok := m[n]; ok {
-			t.Fatalf("number %v already exists", n)
+			assert.Fail(t, "number %v already exists", n)
 		}
 		m[n] = struct{}{}
 	}
@@ -148,11 +150,11 @@ func TestBool(t *testing.T) {
 }
 
 func TestFloat32(t *testing.T) {
-	assert.NotZero(t, Float32())
-	assert.NotZero(t, Float32())
+	assert.GreaterOrEqual(t, Float32(), float32(0))
+	assert.Less(t, Float32(), float32(1))
 }
 
 func TestFloat64(t *testing.T) {
-	assert.NotZero(t, Float64())
-	assert.NotZero(t, Float64())
+	assert.GreaterOrEqual(t, Float64(), 0.0)
+	assert.Less(t, Float64(), 1.0)
 }