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61 lines
1.2 KiB
61 lines
1.2 KiB
// run
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// Copyright 2019 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// short-circuiting interface-to-concrete comparisons
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// will not miss panics
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package main
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import (
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"log"
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"strings"
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)
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func main() {
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var (
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x interface{}
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p *int
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s []int
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l *interface{}
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r []*int
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)
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tests := []struct {
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name string
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errStr string
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f func()
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}{
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{"switch case", "", func() {
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switch x {
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case x.(*int):
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}
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}},
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{"interface conversion", "", func() { _ = x == x.(error) }},
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{"type assertion", "", func() { _ = x == x.(*int) }},
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{"out of bounds", "", func() { _ = x == s[1] }},
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{"nil pointer dereference #1", "", func() { _ = x == *p }},
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{"nil pointer dereference #2", "nil pointer dereference", func() { _ = *l == r[0] }},
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}
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for _, tc := range tests {
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testFuncShouldPanic(tc.name, tc.errStr, tc.f)
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}
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}
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func testFuncShouldPanic(name, errStr string, f func()) {
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defer func() {
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e := recover()
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if e == nil {
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log.Fatalf("%s: comparison did not panic\n", name)
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}
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if errStr != "" {
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if !strings.Contains(e.(error).Error(), errStr) {
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log.Fatalf("%s: wrong panic message\n", name)
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}
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}
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}()
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f()
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}
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