Reland of Add a library for running external commands, providing timeouts and test injection.

go/util/util_test.go

 package util
 
 import (
+        "bytes"
+        "io"
         "regexp"
         "sort"
         "testing"
 
         assert "github.com/stretchr/testify/require"
 )
 
 func TestAtMost(t *testing.T) {
         a := AtMost([]string{"a", "b"}, 3)
         if got, want := len(a), 2; got != want {
@@ skipping 190 matching lines @@
                 "abcdefgh":        false,
                 "defg1234":        true,
                 "cdefg123":        false,
                 "abc.xyz":         true,
                 "abcqxyz":         false,
         }
         for s, e := range tc {
                 assert.Equal(t, e, AnyMatch(slice, s))
         }
 }
+
+func TestIsNil(t *testing.T) {
+        assert.True(t, IsNil(nil))
+        assert.False(t, IsNil(false))
+        assert.False(t, IsNil(0))
+        assert.False(t, IsNil(""))
+        assert.False(t, IsNil([0]int{}))
+        type Empty struct{}
+        assert.False(t, IsNil(Empty{}))
+        assert.True(t, IsNil(chan interface{}(nil)))
+        assert.False(t, IsNil(make(chan interface{})))
+        var f func()
+        assert.True(t, IsNil(f))
+        assert.False(t, IsNil(func() {}))
+        assert.True(t, IsNil(map[bool]bool(nil)))
+        assert.False(t, IsNil(make(map[bool]bool)))
+        assert.True(t, IsNil([]int(nil)))
+        assert.False(t, IsNil([][]int{nil}))
+        assert.True(t, IsNil((*int)(nil)))
+        var i int
+        assert.False(t, IsNil(&i))
+        var pi *int
+        assert.True(t, IsNil(pi))
+        assert.True(t, IsNil(&pi))
+        var ppi **int
+        assert.True(t, IsNil(&ppi))
+        var c chan interface{}
+        assert.True(t, IsNil(&c))
+        var w io.Writer
+        assert.True(t, IsNil(w))
+        w = (*bytes.Buffer)(nil)
+        assert.True(t, IsNil(w))
+        w = &bytes.Buffer{}
+        assert.False(t, IsNil(w))
+        assert.False(t, IsNil(&w))
+        var ii interface{}
+        ii = &pi
+        assert.True(t, IsNil(ii))
+}