github.com/gofunct/common@v0.0.0-20190131174352-fd058c7fbf22/pkg/exec/testing/fake_exec.go

package testingexec

import (
	"context"
	"fmt"
	"io"

	"github.com/gofunct/common/pkg/exec"
)

// FakeExec is a simple scripted Interface type.
type FakeExec struct {
	CommandScript []FakeCommandAction
	CommandCalls  int
	LookPathFunc  func(string) (string, error)
}

var _ exec.Interface = &FakeExec{}

// FakeCommandAction is the function to be executed
type FakeCommandAction func(cmd string, args ...string) exec.Cmd

// Command is to track the commands that are executed
func (fake *FakeExec) Command(cmd string, args ...string) exec.Cmd {
	if fake.CommandCalls > len(fake.CommandScript)-1 {
		panic(fmt.Sprintf("ran out of Command() actions. Could not handle command [%d]: %s args: %v", fake.CommandCalls, cmd, args))
	}
	i := fake.CommandCalls
	fake.CommandCalls++
	return fake.CommandScript[i](cmd, args...)
}

// CommandContext wraps arguments into exec.Cmd
func (fake *FakeExec) CommandContext(ctx context.Context, cmd string, args ...string) exec.Cmd {
	return fake.Command(cmd, args...)
}

// LookPath is for finding the path of a file
func (fake *FakeExec) LookPath(file string) (string, error) {
	return fake.LookPathFunc(file)
}

// FakeCmd is a simple scripted Cmd type.
type FakeCmd struct {
	Argv                 []string
	CombinedOutputScript []FakeCombinedOutputAction
	CombinedOutputCalls  int
	CombinedOutputLog    [][]string
	RunScript            []FakeRunAction
	RunCalls             int
	RunLog               [][]string
	Dirs                 []string
	Stdin                io.Reader
	Stdout               io.Writer
	Stderr               io.Writer
	Env                  []string
	StdoutPipeResponse   FakeStdIOPipeResponse
	StderrPipeResponse   FakeStdIOPipeResponse
	WaitResponse         error
	StartResponse        error
}

var _ exec.Cmd = &FakeCmd{}

// InitFakeCmd is for creating a fake exec.Cmd
func InitFakeCmd(fake *FakeCmd, cmd string, args ...string) exec.Cmd {
	fake.Argv = append([]string{cmd}, args...)
	return fake
}

// FakeStdIOPipeResponse holds responses to use as fakes for the StdoutPipe and
// StderrPipe method calls
type FakeStdIOPipeResponse struct {
	ReadCloser io.ReadCloser
	Error      error
}

// FakeCombinedOutputAction is a function type
type FakeCombinedOutputAction func() ([]byte, error)

// FakeRunAction is a function type
type FakeRunAction func() ([]byte, []byte, error)

// SetDir sets the directory
func (fake *FakeCmd) SetDir(dir string) {
	fake.Dirs = append(fake.Dirs, dir)
}

// SetStdin sets the stdin
func (fake *FakeCmd) SetStdin(in io.Reader) {
	fake.Stdin = in
}

// SetStdout sets the stdout
func (fake *FakeCmd) SetStdout(out io.Writer) {
	fake.Stdout = out
}

// SetStderr sets the stderr
func (fake *FakeCmd) SetStderr(out io.Writer) {
	fake.Stderr = out
}

// SetEnv sets the environment variables
func (fake *FakeCmd) SetEnv(env []string) {
	fake.Env = env
}

// StdoutPipe returns an injected ReadCloser & error (via StdoutPipeResponse)
// to be able to inject an output stream on Stdout
func (fake *FakeCmd) StdoutPipe() (io.ReadCloser, error) {
	return fake.StdoutPipeResponse.ReadCloser, fake.StdoutPipeResponse.Error
}

// StderrPipe returns an injected ReadCloser & error (via StderrPipeResponse)
// to be able to inject an output stream on Stderr
func (fake *FakeCmd) StderrPipe() (io.ReadCloser, error) {
	return fake.StderrPipeResponse.ReadCloser, fake.StderrPipeResponse.Error
}

// Start mimicks starting the process (in the background) and returns the
// injected StartResponse
func (fake *FakeCmd) Start() error {
	return fake.StartResponse
}

// Wait mimicks waiting for the process to exit returns the
// injected WaitResponse
func (fake *FakeCmd) Wait() error {
	return fake.WaitResponse
}

// Run sets runs the command
func (fake *FakeCmd) Run() error {
	if fake.RunCalls > len(fake.RunScript)-1 {
		panic("ran out of Run() actions")
	}
	if fake.RunLog == nil {
		fake.RunLog = [][]string{}
	}
	i := fake.RunCalls
	fake.RunLog = append(fake.RunLog, append([]string{}, fake.Argv...))
	fake.RunCalls++
	stdout, stderr, err := fake.RunScript[i]()
	if stdout != nil {
		fake.Stdout.Write(stdout)
	}
	if stderr != nil {
		fake.Stderr.Write(stderr)
	}
	return err
}

// CombinedOutput returns the output from the command
func (fake *FakeCmd) CombinedOutput() ([]byte, error) {
	if fake.CombinedOutputCalls > len(fake.CombinedOutputScript)-1 {
		panic("ran out of CombinedOutput() actions")
	}
	if fake.CombinedOutputLog == nil {
		fake.CombinedOutputLog = [][]string{}
	}
	i := fake.CombinedOutputCalls
	fake.CombinedOutputLog = append(fake.CombinedOutputLog, append([]string{}, fake.Argv...))
	fake.CombinedOutputCalls++
	return fake.CombinedOutputScript[i]()
}

// Output is the response from the command
func (fake *FakeCmd) Output() ([]byte, error) {
	return nil, fmt.Errorf("unimplemented")
}

// Stop is to stop the process
func (fake *FakeCmd) Stop() {
	// no-op
}

// FakeExitError is a simple fake ExitError type.
type FakeExitError struct {
	Status int
}

var _ exec.ExitError = FakeExitError{}

func (fake FakeExitError) String() string {
	return fmt.Sprintf("exit %d", fake.Status)
}

func (fake FakeExitError) Error() string {
	return fake.String()
}

// Exited always returns true
func (fake FakeExitError) Exited() bool {
	return true
}

// ExitStatus returns the fake status
func (fake FakeExitError) ExitStatus() int {
	return fake.Status
}