s

gitcmd/command.go

@@ -0,0 +1,191 @@
+package gitcmd
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+type Command struct {
+	args    []string
+	dir     string
+	env     []string
+	timeout time.Duration
+	stdin   io.Reader
+	preErrs []error
+}
+
+func NewCommand(args ...string) *Command {
+	c := &Command{}
+	for _, arg := range args {
+		if !isTrustedArg(arg) {
+			c.preErrs = append(c.preErrs, fmt.Errorf("untrusted argument in NewCommand: %q", arg))
+		}
+	}
+	c.args = append(c.args, args...)
+	return c
+}
+
+func isTrustedArg(arg string) bool {
+	if arg == "" {
+		return true
+	}
+	for _, r := range arg {
+		switch r {
+		case ';', '`', '$', '|', '&', '\n', '\r':
+			return false
+		}
+	}
+	return true
+}
+
+func isSafeValue(arg string) bool {
+	return !strings.HasPrefix(arg, "-")
+}
+
+func (c *Command) Add(args ...string) *Command {
+	for _, arg := range args {
+		if !isTrustedArg(arg) {
+			c.preErrs = append(c.preErrs, fmt.Errorf("untrusted argument in Add: %q", arg))
+		}
+	}
+	if len(c.preErrs) == 0 {
+		c.args = append(c.args, args...)
+	}
+	return c
+}
+
+func (c *Command) AddOptionValues(opt string, values ...string) *Command {
+	if !isTrustedArg(opt) || !strings.HasPrefix(opt, "-") {
+		c.preErrs = append(c.preErrs, fmt.Errorf("invalid option in AddOptionValues: %q", opt))
+		return c
+	}
+	c.args = append(c.args, opt)
+	c.AddDynamicArguments(values...)
+	return c
+}
+
+func (c *Command) AddDynamicArguments(args ...string) *Command {
+	for _, arg := range args {
+		if !isSafeValue(arg) {
+			c.preErrs = append(c.preErrs, fmt.Errorf("user argument cannot start with '-': %q", arg))
+		}
+	}
+	if len(c.preErrs) == 0 {
+		c.args = append(c.args, args...)
+	}
+	return c
+}
+
+func (c *Command) AddDashesAndList(list ...string) *Command {
+	c.args = append(c.args, "--")
+	c.args = append(c.args, list...)
+	return c
+}
+
+func (c *Command) WithDir(dir string) *Command {
+	c.dir = dir
+	return c
+}
+
+func (c *Command) WithEnv(env ...string) *Command {
+	c.env = append(c.env, env...)
+	return c
+}
+
+func (c *Command) WithTimeout(d time.Duration) *Command {
+	c.timeout = d
+	return c
+}
+
+func (c *Command) WithStdin(r io.Reader) *Command {
+	c.stdin = r
+	return c
+}
+
+func (c *Command) CmdString() string {
+	exe, err := Executable()
+	if err != nil {
+		exe = "git"
+	}
+	parts := append([]string{exe}, c.args...)
+	for i, p := range parts {
+		if strings.ContainsAny(p, " `'\"\t\n") {
+			parts[i] = fmt.Sprintf("%q", p)
+		}
+	}
+	return strings.Join(parts, " ")
+}
+
+func (c *Command) Run(ctx context.Context) error {
+	_, _, err := c.RunStdString(ctx)
+	return err
+}
+
+func (c *Command) RunStdString(ctx context.Context) (stdout, stderr string, err error) {
+	outb, errb, err := c.RunStdBytes(ctx)
+	return string(outb), string(errb), err
+}
+
+func (c *Command) RunStdBytes(ctx context.Context) (stdout, stderr []byte, err error) {
+	if len(c.preErrs) > 0 {
+		return nil, nil, errors.Join(c.preErrs...)
+	}
+
+	exe, err := Executable()
+	if err != nil {
+		return nil, nil, fmt.Errorf("git executable not found: %w", err)
+	}
+
+	var cancel context.CancelFunc
+	if c.timeout > 0 {
+		ctx, cancel = context.WithTimeout(ctx, c.timeout)
+		defer cancel()
+	}
+
+	cmd := exec.CommandContext(ctx, exe, c.args...)
+	cmd.Dir = c.dir
+	cmd.Env = append(os.Environ(), CommonEnvs()...)
+	cmd.Env = append(cmd.Env, c.env...)
+	cmd.Stdin = c.stdin
+
+	var stdoutBuf, stderrBuf bytes.Buffer
+	cmd.Stdout = &stdoutBuf
+	cmd.Stderr = &stderrBuf
+
+	err = cmd.Run()
+	return stdoutBuf.Bytes(), stderrBuf.Bytes(), err
+}
+
+func (c *Command) RunPiped(ctx context.Context, stdout, stderr io.Writer) error {
+	if len(c.preErrs) > 0 {
+		return errors.Join(c.preErrs...)
+	}
+
+	exe, err := Executable()
+	if err != nil {
+		return fmt.Errorf("git executable not found: %w", err)
+	}
+
+	var cancel context.CancelFunc
+	if c.timeout > 0 {
+		ctx, cancel = context.WithTimeout(ctx, c.timeout)
+		defer cancel()
+	}
+
+	cmd := exec.CommandContext(ctx, exe, c.args...)
+	cmd.Dir = c.dir
+	cmd.Env = append(os.Environ(), CommonEnvs()...)
+	cmd.Env = append(cmd.Env, c.env...)
+	cmd.Stdin = c.stdin
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+
+	return cmd.Run()
+}