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// Copyright 2020 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.
package main
import (
"go/token"
"os"
"os/exec"
"reflect"
"runtime"
"strings"
"testing"
)
// TestIsTest verifies that the isTest helper function matches
// exactly (and only) the names of functions recognized as tests.
func TestIsTest(t *testing.T) {
cmd := exec.Command(os.Args[0], "-test.list=.")
out, err := cmd.CombinedOutput()
if err != nil {
t.Fatalf("%s: %v\n%s", strings.Join(cmd.Args, " "), err, out)
}
t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out)
isTestFunction := map[string]bool{}
lines := strings.Split(string(out), "\n")
for _, line := range lines {
isTestFunction[strings.TrimSpace(line)] = true
}
for _, tc := range []struct {
prefix string
f interface{}
want bool
}{
{"Test", Test, true},
{"Test", TestIsTest, true},
{"Test", Test1IsATest, true},
{"Test", TestÑIsATest, true},
{"Test", TestisNotATest, false},
{"Example", Example, true},
{"Example", ExampleTest, true},
{"Example", Example_isAnExample, true},
{"Example", ExampleTest_isAnExample, true},
// Example_noOutput has a valid example function name but lacks an output
// declaration, but the isTest function operates only on the test name
// so it cannot detect that the function is not a test.
{"Example", Example1IsAnExample, true},
{"Example", ExampleisNotAnExample, false},
{"Benchmark", Benchmark, true},
{"Benchmark", BenchmarkNop, true},
{"Benchmark", Benchmark1IsABenchmark, true},
{"Benchmark", BenchmarkisNotABenchmark, false},
} {
name := nameOf(t, tc.f)
t.Run(name, func(t *testing.T) {
if tc.want != isTestFunction[name] {
t.Fatalf(".want (%v) is inconsistent with -test.list", tc.want)
}
if !strings.HasPrefix(name, tc.prefix) {
t.Fatalf("%q is not a prefix of %v", tc.prefix, name)
}
got := isTest(name, tc.prefix)
if got != tc.want {
t.Errorf(`isTest(%q, %q) = %v; want %v`, name, tc.prefix, got, tc.want)
}
})
}
}
// nameOf returns the runtime-reported name of function f.
func nameOf(t *testing.T, f interface{}) string {
t.Helper()
v := reflect.ValueOf(f)
if v.Kind() != reflect.Func {
t.Fatalf("%v is not a function", f)
}
rf := runtime.FuncForPC(v.Pointer())
if rf == nil {
t.Fatalf("%v.Pointer() is not a known function", f)
}
fullName := rf.Name()
parts := strings.Split(fullName, ".")
name := parts[len(parts)-1]
if !token.IsIdentifier(name) {
t.Fatalf("%q is not a valid identifier", name)
}
return name
}
// TestisNotATest is not a test function, despite appearances.
//
// Please ignore any lint or vet warnings for this function.
func TestisNotATest(t *testing.T) {
panic("This is not a valid test function.")
}
// Test11IsATest is a valid test function.
func Test1IsATest(t *testing.T) {
}
// Test is a test with a minimal name.
func Test(t *testing.T) {
}
// TestÑIsATest is a test with an interesting Unicode name.
func TestÑIsATest(t *testing.T) {
}
func Example() {
// Output:
}
func ExampleTest() {
// This is an example for the function Test.
// ❤ recursion.
Test(nil)
// Output:
}
func Example1IsAnExample() {
// Output:
}
// ExampleisNotAnExample is not an example function, despite appearances.
//
// Please ignore any lint or vet warnings for this function.
func ExampleisNotAnExample() {
panic("This is not a valid example function.")
// Output:
// None. (This is not really an example function.)
}
func Example_isAnExample() {
// Output:
}
func ExampleTest_isAnExample() {
Test(nil)
// Output:
}
func Example_noOutput() {
// No output declared: should be compiled but not run.
}
func Benchmark(b *testing.B) {
for i := 0; i < b.N; i++ {
}
}
func BenchmarkNop(b *testing.B) {
for i := 0; i < b.N; i++ {
}
}
func Benchmark1IsABenchmark(b *testing.B) {
for i := 0; i < b.N; i++ {
}
}
// BenchmarkisNotABenchmark is not a benchmark function, despite appearances.
//
// Please ignore any lint or vet warnings for this function.
func BenchmarkisNotABenchmark(b *testing.B) {
panic("This is not a valid benchmark function.")
}