spf13--cobra/cobra_test.go
aarzilli 0619d2498f Restructure code to let linker perform deadcode elimination step
Cobra, in its default configuration, will execute a template to generate
help, usage and version outputs. Text/template execution calls MethodByName
and MethodByName disables dead code elimination in the Go linker, therefore
all programs that make use of cobra will be linked with dead code
elimination disabled, even if they end up replacing the default usage, help
and version formatters with a custom function and no actual text/template
evaluations are ever made at runtime.

Dead code elimination in the linker helps reduce disk space and memory
utilization of programs. For example, for the simple example program used by
TestDeadcodeElimination 40% of the final executable size is dead code. For a
more realistic example, 12% of the size of Delve's executable is deadcode.

This PR changes Cobra so that, in its default configuration, it does not
automatically inhibit deadcode elimination by:

1. changing Cobra's default behavior to emit output for usage and help using
   simple Go functions instead of template execution
2. quarantining all calls to template execution into SetUsageTemplate,
   SetHelpTemplate and SetVersionTemplate so that the linker can statically
   determine if they are reachable
2024-12-06 16:39:12 +01:00

282 lines
6.1 KiB
Go

// Copyright 2013-2023 The Cobra Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cobra
import (
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
"text/template"
)
func assertNoErr(t *testing.T, e error) {
if e != nil {
t.Error(e)
}
}
func TestAddTemplateFunctions(t *testing.T) {
AddTemplateFunc("t", func() bool { return true })
AddTemplateFuncs(template.FuncMap{
"f": func() bool { return false },
"h": func() string { return "Hello," },
"w": func() string { return "world." }})
c := &Command{}
c.SetUsageTemplate(`{{if t}}{{h}}{{end}}{{if f}}{{h}}{{end}} {{w}}`)
const expected = "Hello, world."
if got := c.UsageString(); got != expected {
t.Errorf("Expected UsageString: %v\nGot: %v", expected, got)
}
}
func TestLevenshteinDistance(t *testing.T) {
tests := []struct {
name string
s string
t string
ignoreCase bool
expected int
}{
{
name: "Equal strings (case-sensitive)",
s: "hello",
t: "hello",
ignoreCase: false,
expected: 0,
},
{
name: "Equal strings (case-insensitive)",
s: "Hello",
t: "hello",
ignoreCase: true,
expected: 0,
},
{
name: "Different strings (case-sensitive)",
s: "kitten",
t: "sitting",
ignoreCase: false,
expected: 3,
},
{
name: "Different strings (case-insensitive)",
s: "Kitten",
t: "Sitting",
ignoreCase: true,
expected: 3,
},
{
name: "Empty strings",
s: "",
t: "",
ignoreCase: false,
expected: 0,
},
{
name: "One empty string",
s: "abc",
t: "",
ignoreCase: false,
expected: 3,
},
{
name: "Both empty strings",
s: "",
t: "",
ignoreCase: true,
expected: 0,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Act
got := ld(tt.s, tt.t, tt.ignoreCase)
// Assert
if got != tt.expected {
t.Errorf("Expected ld: %v\nGot: %v", tt.expected, got)
}
})
}
}
func TestStringInSlice(t *testing.T) {
tests := []struct {
name string
a string
list []string
expected bool
}{
{
name: "String in slice (case-sensitive)",
a: "apple",
list: []string{"orange", "banana", "apple", "grape"},
expected: true,
},
{
name: "String not in slice (case-sensitive)",
a: "pear",
list: []string{"orange", "banana", "apple", "grape"},
expected: false,
},
{
name: "String in slice (case-insensitive)",
a: "APPLE",
list: []string{"orange", "banana", "apple", "grape"},
expected: false,
},
{
name: "Empty slice",
a: "apple",
list: []string{},
expected: false,
},
{
name: "Empty string",
a: "",
list: []string{"orange", "banana", "apple", "grape"},
expected: false,
},
{
name: "Empty strings match",
a: "",
list: []string{"orange", ""},
expected: true,
},
{
name: "Empty string in empty slice",
a: "",
list: []string{},
expected: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Act
got := stringInSlice(tt.a, tt.list)
// Assert
if got != tt.expected {
t.Errorf("Expected stringInSlice: %v\nGot: %v", tt.expected, got)
}
})
}
}
func TestRpad(t *testing.T) {
tests := []struct {
name string
inputString string
padding int
expected string
}{
{
name: "Padding required",
inputString: "Hello",
padding: 10,
expected: "Hello ",
},
{
name: "No padding required",
inputString: "World",
padding: 5,
expected: "World",
},
{
name: "Empty string",
inputString: "",
padding: 8,
expected: " ",
},
{
name: "Zero padding",
inputString: "cobra",
padding: 0,
expected: "cobra",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Act
got := rpad(tt.inputString, tt.padding)
// Assert
if got != tt.expected {
t.Errorf("Expected rpad: %v\nGot: %v", tt.expected, got)
}
})
}
}
func TestDeadcodeElimination(t *testing.T) {
// check that a simple program using cobra in its default configuration is
// linked with deadcode elimination enabled.
const (
dirname = "test_deadcode"
progname = "test_deadcode_elimination"
)
os.Mkdir(dirname, 0770)
filename := filepath.Join(dirname, progname+".go")
err := os.WriteFile(filename, []byte(`package main
import (
"fmt"
"os"
"github.com/spf13/cobra"
)
var rootCmd = &cobra.Command{
Version: "1.0",
Use: "example_program",
Short: "example_program - test fixture to check that deadcode elimination is allowed",
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("hello world")
},
Aliases: []string{"alias1", "alias2"},
Example: "stringer --help",
}
func main() {
if err := rootCmd.Execute(); err != nil {
fmt.Fprintf(os.Stderr, "Whoops. There was an error while executing your CLI '%s'", err)
os.Exit(1)
}
}
`), 0660)
if err != nil {
t.Fatalf("could not write test program: %v", err)
}
defer os.RemoveAll(dirname)
buf, err := exec.Command("go", "build", filename).CombinedOutput()
if err != nil {
t.Fatalf("could not compile test program: %s", string(buf))
}
defer os.Remove(progname)
buf, err = exec.Command("go", "tool", "nm", progname).CombinedOutput()
if err != nil {
t.Fatalf("could not run go tool nm: %v", err)
}
if strings.Contains(string(buf), "MethodByName") {
t.Error("compiled programs contains MethodByName symbol")
}
}