gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/rand/rng_test.go (about)

     1  // Copyright 2023 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package rand
    16  
    17  import (
    18  	"math/rand"
    19  	"testing"
    20  )
    21  
    22  const testIterations = 100_000
    23  
    24  func TestInt63n(t *testing.T) {
    25  	for i := 0; i < testIterations; i++ {
    26  		maximum := rand.Int63()
    27  		for maximum <= 0 {
    28  			maximum = rand.Int63()
    29  		}
    30  		if n := Int63n(maximum); n >= maximum || n < 0 {
    31  			t.Errorf("Int63n(%d) returned bad value %d", maximum, n)
    32  		}
    33  	}
    34  }
    35  
    36  func TestInt63(t *testing.T) {
    37  	for i := 0; i < testIterations; i++ {
    38  		if n := Int63(); n < 0 {
    39  			t.Errorf("Int63() returned bad value %d", n)
    40  		}
    41  	}
    42  }