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go/test/nil.go
Alan Donovan 052c942e20 test: ensure all failing tests exit nonzero.
Previously merely printing an error would cause the golden
file comparison (in 'bash run') to fail, but that is no longer
the case with the new run.go driver.

R=iant
CC=golang-dev
https://golang.org/cl/7310087
2013-02-12 13:17:49 -05:00

181 lines
2.2 KiB
Go

// run
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Test nil.
package main
import (
"fmt"
"time"
)
type T struct {
i int
}
type IN interface{}
func main() {
var i *int
var f *float32
var s *string
var m map[float32]*int
var c chan int
var t *T
var in IN
var ta []IN
i = nil
f = nil
s = nil
m = nil
c = nil
t = nil
i = nil
ta = make([]IN, 1)
ta[0] = nil
_, _, _, _, _, _, _, _ = i, f, s, m, c, t, in, ta
arraytest()
chantest()
maptest()
slicetest()
}
func shouldPanic(f func()) {
defer func() {
if recover() == nil {
panic("not panicking")
}
}()
f()
}
func shouldBlock(f func()) {
go func() {
f()
panic("did not block")
}()
time.Sleep(1e7)
}
// nil array pointer
func arraytest() {
var p *[10]int
// Looping over indices is fine.
s := 0
for i := range p {
s += i
}
if s != 45 {
panic(s)
}
s = 0
for i := 0; i < len(p); i++ {
s += i
}
if s != 45 {
panic(s)
}
// Looping over values is not.
shouldPanic(func() {
for i, v := range p {
s += i + v
}
})
shouldPanic(func() {
for i := 0; i < len(p); i++ {
s += p[i]
}
})
}
// nil channel
// select tests already handle select on nil channel
func chantest() {
var ch chan int
// nil channel is never ready
shouldBlock(func() {
ch <- 1
})
shouldBlock(func() {
<-ch
})
shouldBlock(func() {
x, ok := <-ch
println(x, ok) // unreachable
})
if len(ch) != 0 {
panic(len(ch))
}
if cap(ch) != 0 {
panic(cap(ch))
}
}
// nil map
func maptest() {
var m map[int]int
// nil map appears empty
if len(m) != 0 {
panic(len(m))
}
if m[1] != 0 {
panic(m[1])
}
if x, ok := m[1]; x != 0 || ok {
panic(fmt.Sprint(x, ok))
}
for k, v := range m {
panic(k)
panic(v)
}
// can delete (non-existent) entries
delete(m, 2)
// but cannot be written to
shouldPanic(func() {
m[2] = 3
})
}
// nil slice
func slicetest() {
var x []int
// nil slice is just a 0-element slice.
if len(x) != 0 {
panic(len(x))
}
if cap(x) != 0 {
panic(cap(x))
}
// no 0-element slices can be read from or written to
var s int
shouldPanic(func() {
s += x[1]
})
shouldPanic(func() {
x[2] = s
})
}