feature: Allow following output (evilmartians#397)

Closes evilmartians#208

docs/configuration.md

@@ -18,6 +18,7 @@
  - [`files`](#files-global)
  - [`parallel`](#parallel)
  - [`piped`](#piped)
+ - [`follow`](#follow)
  - [`exclude_tags`](#exclude_tags)
  - [`commands`](#commands)
  - [`scripts`](#scripts)
@@ -339,6 +340,29 @@ database:
  run: rake db:seed
 ```
 
+### `follow`
+
+**Default: `false`**
+
+Follow the STDOUT of the running commands and scripts.
+
+**Example**
+
+```yml
+# lefthook.yml
+
+pre-push:
+ follow: true
+ commands:
+ backend-tests:
+ run: bundle exec rspec
+ frontend-tests:
+ run: yarn test
+```
+
+**Notes**
+
+If used with [`parallel`](#parallel) the output can be a mess, so please avoid setting both options to `true`.
 
 ### `exclude_tags`
 

internal/config/hook.go

@@ -30,6 +30,7 @@ type Hook struct {
  Piped bool `mapstructure:"piped"`
  ExcludeTags []string `mapstructure:"exclude_tags"`
  Skip interface{} `mapstructure:"skip"`
+ Follow bool `mapstructure:"follow"`
 }
 
 func (h *Hook) Validate() error {

internal/lefthook/run.go

@@ -103,13 +103,15 @@ Run 'lefthook install' manually.`,
  resultChan := make(chan runner.Result, len(hook.Commands)+len(hook.Scripts))
 
  run := runner.NewRunner(
- l.Fs,
- l.repo,
- hook,
- gitArgs,
- resultChan,
- logSettings,
- cfg.NoTTY || args.NoTTY,
+ runner.Opts{
+ Fs: l.Fs,
+ Repo: l.repo,
+ Hook: hook,
+ GitArgs: gitArgs,
+ ResultChan: resultChan,
+ SkipSettings: logSettings,
+ DisableTTY: cfg.NoTTY || args.NoTTY,
+ },
  )
 
  sourceDirs := []string{

internal/lefthook/runner/execute_unix.go

@@ -20,7 +20,7 @@ import (
 
 type CommandExecutor struct{}
 
-func (e CommandExecutor) Execute(opts ExecuteOptions) (*bytes.Buffer, error) {
+func (e CommandExecutor) Execute(opts ExecuteOptions, out io.Writer) error {
  stdin := os.Stdin
  if opts.interactive && !isatty.IsTerminal(os.Stdin.Fd()) {
  tty, err := os.Open("/dev/tty")
@@ -47,33 +47,30 @@ func (e CommandExecutor) Execute(opts ExecuteOptions) (*bytes.Buffer, error) {
 
  command.Env = append(os.Environ(), envList...)
 
- var out *bytes.Buffer
-
  if opts.interactive {
  command.Stdout = os.Stdout
  command.Stdin = stdin
  command.Stderr = os.Stderr
  err := command.Start()
  if err != nil {
- return nil, err
+ return err
  }
  } else {
  p, err := pty.Start(command)
  if err != nil {
- return nil, err
+ return err
  }
 
  defer func() { _ = p.Close() }()
 
  go func() { _, _ = io.Copy(p, stdin) }()
 
- out = bytes.NewBuffer(make([]byte, 0))
  _, _ = io.Copy(out, p)
  }
 
  defer func() { _ = command.Process.Kill() }()
 
- return out, command.Wait()
+ return command.Wait()
 }
 
 func (e CommandExecutor) RawExecute(command string, args ...string) (*bytes.Buffer, error) {

internal/lefthook/runner/execute_windows.go

@@ -3,6 +3,7 @@ package runner
 import (
  "bytes"
  "fmt"
+ "io"
  "os"
  "os/exec"
  "path/filepath"
@@ -12,7 +13,7 @@ import (
 
 type CommandExecutor struct{}
 
-func (e CommandExecutor) Execute(opts ExecuteOptions) (*bytes.Buffer, error) {
+func (e CommandExecutor) Execute(opts ExecuteOptions, out io.Writer) error {
  command := exec.Command(opts.args[0])
  command.SysProcAttr = &syscall.SysProcAttr{
  CmdLine: strings.Join(opts.args, " "),
@@ -31,24 +32,22 @@ func (e CommandExecutor) Execute(opts ExecuteOptions) (*bytes.Buffer, error) {
 
  command.Env = append(os.Environ(), envList...)
 
- var out bytes.Buffer
-
  if opts.interactive {
  command.Stdout = os.Stdout
  } else {
- command.Stdout = &out
+ command.Stdout = out
  }
 
  command.Stdin = os.Stdin
  command.Stderr = os.Stderr
  err := command.Start()
  if err != nil {
- return nil, err
+ return err
  }
 
  defer func() { _ = command.Process.Kill() }()
 
- return &out, command.Wait()
+ return command.Wait()
 }
 
 func (e CommandExecutor) RawExecute(command string, args ...string) (*bytes.Buffer, error) {

internal/lefthook/runner/executor.go

@@ -2,6 +2,7 @@ package runner
 
 import (
  "bytes"
+ "io"
 )
 
 // ExecutorOptions contains the options that control the execution.
@@ -15,6 +16,6 @@ type ExecuteOptions struct {
 // Executor provides an interface for command execution.
 // It is used here for testing purpose mostly.
 type Executor interface {
- Execute(opts ExecuteOptions) (*bytes.Buffer, error)
+ Execute(opts ExecuteOptions, out io.Writer) error
  RawExecute(command string, args ...string) (*bytes.Buffer, error)
 }