cli/git/client.go
Tyler McGoffin e1423cdbbf Refine error handling of ReadBranchConfig
cmd.Output() will return an error when the git command ran successfully
but had no output. To handle this, we can check Stderr, as we expect it to
be populated for any ExitErrors or otherwise when there is a command
failure.

This allows for propagation of this error handling up the call chain, so
we are now returning errors if the call to git fails instead of just
handing off an empty BranchConfig and suppressing the errors.

Additionally, I've removed some more naked returns that I found in
pkg/cmd/pr/create.go createRun
2025-01-09 11:45:15 -08:00

824 lines
22 KiB
Go

package git
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"net/url"
"os/exec"
"path"
"regexp"
"runtime"
"slices"
"sort"
"strings"
"sync"
"github.com/cli/cli/v2/internal/ghinstance"
"github.com/cli/safeexec"
)
// MergeBaseConfig is the configuration setting to keep track of the PR target branch.
const MergeBaseConfig = "gh-merge-base"
var remoteRE = regexp.MustCompile(`(.+)\s+(.+)\s+\((push|fetch)\)`)
// This regexp exists to match lines of the following form:
// 6a6872b918c601a0e730710ad8473938a7516d30\u0000title 1\u0000Body 1\u0000\n
// 7a6872b918c601a0e730710ad8473938a7516d31\u0000title 2\u0000Body 2\u0000
//
// This is the format we use when collecting commit information,
// with null bytes as separators. Using null bytes this way allows for us
// to easily maintain newlines that might be in the body.
//
// The ?m modifier is the multi-line modifier, meaning that ^ and $
// match the beginning and end of lines, respectively.
//
// The [\S\s] matches any whitespace or non-whitespace character,
// which is different from .* because it allows for newlines as well.
//
// The ? following .* and [\S\s] is a lazy modifier, meaning that it will
// match as few characters as possible while still satisfying the rest of the regexp.
// This is important because it allows us to match the first null byte after the title and body,
// rather than the last null byte in the entire string.
var commitLogRE = regexp.MustCompile(`(?m)^[0-9a-fA-F]{7,40}\x00.*?\x00[\S\s]*?\x00$`)
type errWithExitCode interface {
ExitCode() int
}
type Client struct {
GhPath string
RepoDir string
GitPath string
Stderr io.Writer
Stdin io.Reader
Stdout io.Writer
commandContext commandCtx
mu sync.Mutex
}
func (c *Client) Copy() *Client {
return &Client{
GhPath: c.GhPath,
RepoDir: c.RepoDir,
GitPath: c.GitPath,
Stderr: c.Stderr,
Stdin: c.Stdin,
Stdout: c.Stdout,
commandContext: c.commandContext,
}
}
func (c *Client) Command(ctx context.Context, args ...string) (*Command, error) {
if c.RepoDir != "" {
args = append([]string{"-C", c.RepoDir}, args...)
}
commandContext := exec.CommandContext
if c.commandContext != nil {
commandContext = c.commandContext
}
var err error
c.mu.Lock()
if c.GitPath == "" {
c.GitPath, err = resolveGitPath()
}
c.mu.Unlock()
if err != nil {
return nil, err
}
cmd := commandContext(ctx, c.GitPath, args...)
cmd.Stderr = c.Stderr
cmd.Stdin = c.Stdin
cmd.Stdout = c.Stdout
return &Command{cmd}, nil
}
// CredentialPattern is used to inform AuthenticatedCommand which patterns Git should match
// against when trying to find credentials. It is a little over-engineered as a type because we
// want AuthenticatedCommand to have a clear compilation error when this is not provided,
// as opposed to using a string which might compile with `client.AuthenticatedCommand(ctx, "fetch")`.
//
// It is only usable when constructed by another function in the package because the empty pattern,
// without allMatching set to true, will result in an error in AuthenticatedCommand.
//
// Callers can currently opt-in to an slightly less secure mode for backwards compatibility by using
// AllMatchingCredentialsPattern.
type CredentialPattern struct {
allMatching bool // should only be constructable via AllMatchingCredentialsPattern
pattern string
}
// AllMatchingCredentialsPattern allows for setting gh as credential helper for all hosts.
// However, we should endeavour to remove it as it's less secure.
var AllMatchingCredentialsPattern = CredentialPattern{allMatching: true, pattern: ""}
var disallowedCredentialPattern = CredentialPattern{allMatching: false, pattern: ""}
// CredentialPatternFromGitURL takes a git remote URL e.g. "https://github.com/cli/cli.git" or
// "git@github.com:cli/cli.git" and returns the credential pattern that should be used for it.
func CredentialPatternFromGitURL(gitURL string) (CredentialPattern, error) {
normalizedURL, err := ParseURL(gitURL)
if err != nil {
return CredentialPattern{}, fmt.Errorf("failed to parse remote URL: %w", err)
}
return CredentialPatternFromHost(normalizedURL.Host), nil
}
// CredentialPatternFromHost expects host to be in the form "github.com" and returns
// the credential pattern that should be used for it.
// It does not perform any canonicalisation e.g. "api.github.com" will not work as expected.
func CredentialPatternFromHost(host string) CredentialPattern {
return CredentialPattern{
pattern: strings.TrimSuffix(ghinstance.HostPrefix(host), "/"),
}
}
// AuthenticatedCommand is a wrapper around Command that included configuration to use gh
// as the credential helper for git.
func (c *Client) AuthenticatedCommand(ctx context.Context, credentialPattern CredentialPattern, args ...string) (*Command, error) {
if c.GhPath == "" {
// Assumes that gh is in PATH.
c.GhPath = "gh"
}
credHelper := fmt.Sprintf("!%q auth git-credential", c.GhPath)
var preArgs []string
if credentialPattern == disallowedCredentialPattern {
return nil, fmt.Errorf("empty credential pattern is not allowed unless provided explicitly")
} else if credentialPattern == AllMatchingCredentialsPattern {
preArgs = []string{"-c", "credential.helper="}
preArgs = append(preArgs, "-c", fmt.Sprintf("credential.helper=%s", credHelper))
} else {
preArgs = []string{"-c", fmt.Sprintf("credential.%s.helper=", credentialPattern.pattern)}
preArgs = append(preArgs, "-c", fmt.Sprintf("credential.%s.helper=%s", credentialPattern.pattern, credHelper))
}
args = append(preArgs, args...)
return c.Command(ctx, args...)
}
func (c *Client) Remotes(ctx context.Context) (RemoteSet, error) {
remoteArgs := []string{"remote", "-v"}
remoteCmd, err := c.Command(ctx, remoteArgs...)
if err != nil {
return nil, err
}
remoteOut, remoteErr := remoteCmd.Output()
if remoteErr != nil {
return nil, remoteErr
}
configArgs := []string{"config", "--get-regexp", `^remote\..*\.gh-resolved$`}
configCmd, err := c.Command(ctx, configArgs...)
if err != nil {
return nil, err
}
configOut, configErr := configCmd.Output()
if configErr != nil {
// Ignore exit code 1 as it means there are no resolved remotes.
var gitErr *GitError
if ok := errors.As(configErr, &gitErr); ok && gitErr.ExitCode != 1 {
return nil, gitErr
}
}
remotes := parseRemotes(outputLines(remoteOut))
populateResolvedRemotes(remotes, outputLines(configOut))
sort.Sort(remotes)
return remotes, nil
}
func (c *Client) UpdateRemoteURL(ctx context.Context, name, url string) error {
args := []string{"remote", "set-url", name, url}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) SetRemoteResolution(ctx context.Context, name, resolution string) error {
args := []string{"config", "--add", fmt.Sprintf("remote.%s.gh-resolved", name), resolution}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
// CurrentBranch reads the checked-out branch for the git repository.
func (c *Client) CurrentBranch(ctx context.Context) (string, error) {
args := []string{"symbolic-ref", "--quiet", "HEAD"}
cmd, err := c.Command(ctx, args...)
if err != nil {
return "", err
}
out, err := cmd.Output()
if err != nil {
var gitErr *GitError
if ok := errors.As(err, &gitErr); ok && len(gitErr.Stderr) == 0 {
gitErr.err = ErrNotOnAnyBranch
gitErr.Stderr = "not on any branch"
return "", gitErr
}
return "", err
}
branch := firstLine(out)
return strings.TrimPrefix(branch, "refs/heads/"), nil
}
// ShowRefs resolves fully-qualified refs to commit hashes.
func (c *Client) ShowRefs(ctx context.Context, refs []string) ([]Ref, error) {
args := append([]string{"show-ref", "--verify", "--"}, refs...)
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil, err
}
// This functionality relies on parsing output from the git command despite
// an error status being returned from git.
out, err := cmd.Output()
var verified []Ref
for _, line := range outputLines(out) {
parts := strings.SplitN(line, " ", 2)
if len(parts) < 2 {
continue
}
verified = append(verified, Ref{
Hash: parts[0],
Name: parts[1],
})
}
return verified, err
}
func (c *Client) Config(ctx context.Context, name string) (string, error) {
args := []string{"config", name}
cmd, err := c.Command(ctx, args...)
if err != nil {
return "", err
}
out, err := cmd.Output()
if err != nil {
var gitErr *GitError
if ok := errors.As(err, &gitErr); ok && gitErr.ExitCode == 1 {
gitErr.Stderr = fmt.Sprintf("unknown config key %s", name)
return "", gitErr
}
return "", err
}
return firstLine(out), nil
}
func (c *Client) UncommittedChangeCount(ctx context.Context) (int, error) {
args := []string{"status", "--porcelain"}
cmd, err := c.Command(ctx, args...)
if err != nil {
return 0, err
}
out, err := cmd.Output()
if err != nil {
return 0, err
}
lines := strings.Split(string(out), "\n")
count := 0
for _, l := range lines {
if l != "" {
count++
}
}
return count, nil
}
func (c *Client) Commits(ctx context.Context, baseRef, headRef string) ([]*Commit, error) {
// The formatting directive %x00 indicates that git should include the null byte as a separator.
// We use this because it is not a valid character to include in a commit message. Previously,
// commas were used here but when we Split on them, we would get incorrect results if commit titles
// happened to contain them.
// https://git-scm.com/docs/pretty-formats#Documentation/pretty-formats.txt-emx00em
args := []string{"-c", "log.ShowSignature=false", "log", "--pretty=format:%H%x00%s%x00%b%x00", "--cherry", fmt.Sprintf("%s...%s", baseRef, headRef)}
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil, err
}
out, err := cmd.Output()
if err != nil {
return nil, err
}
commits := []*Commit{}
commitLogs := commitLogRE.FindAllString(string(out), -1)
for _, commitLog := range commitLogs {
// Each line looks like this:
// 6a6872b918c601a0e730710ad8473938a7516d30\u0000title 1\u0000Body 1\u0000\n
// Or with an optional body:
// 6a6872b918c601a0e730710ad8473938a7516d30\u0000title 1\u0000\u0000\n
// Therefore after splitting we will have:
// ["6a6872b918c601a0e730710ad8473938a7516d30", "title 1", "Body 1", ""]
// Or with an optional body:
// ["6a6872b918c601a0e730710ad8473938a7516d30", "title 1", "", ""]
commitLogParts := strings.Split(commitLog, "\u0000")
commits = append(commits, &Commit{
Sha: commitLogParts[0],
Title: commitLogParts[1],
Body: commitLogParts[2],
})
}
if len(commits) == 0 {
return nil, fmt.Errorf("could not find any commits between %s and %s", baseRef, headRef)
}
return commits, nil
}
func (c *Client) LastCommit(ctx context.Context) (*Commit, error) {
output, err := c.lookupCommit(ctx, "HEAD", "%H,%s")
if err != nil {
return nil, err
}
idx := bytes.IndexByte(output, ',')
return &Commit{
Sha: string(output[0:idx]),
Title: strings.TrimSpace(string(output[idx+1:])),
}, nil
}
func (c *Client) CommitBody(ctx context.Context, sha string) (string, error) {
output, err := c.lookupCommit(ctx, sha, "%b")
return string(output), err
}
func (c *Client) lookupCommit(ctx context.Context, sha, format string) ([]byte, error) {
args := []string{"-c", "log.ShowSignature=false", "show", "-s", "--pretty=format:" + format, sha}
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil, err
}
out, err := cmd.Output()
if err != nil {
return nil, err
}
return out, nil
}
// ReadBranchConfig parses the `branch.BRANCH.(remote|merge|gh-merge-base)` part of git config.
// If no branch config is found or there is an error in the command, it returns an empty BranchConfig.
// Downstream consumers of ReadBranchConfig should consider the behavior they desire if this errors,
// as an empty config is not necessarily breaking.
func (c *Client) ReadBranchConfig(ctx context.Context, branch string) (BranchConfig, error) {
prefix := regexp.QuoteMeta(fmt.Sprintf("branch.%s.", branch))
args := []string{"config", "--get-regexp", fmt.Sprintf("^%s(remote|merge|%s)$", prefix, MergeBaseConfig)}
cmd, err := c.Command(ctx, args...)
if err != nil {
return BranchConfig{}, err
}
out, err := cmd.Output()
if err != nil {
// This will error if no matches are found but the git command still ran successfully. We only
// want to return an error if the command failed to run, usually and ExitError, which will be
// indicated by output on Stderr.
if err.(*GitError).Stderr != "" {
return BranchConfig{}, err
}
return BranchConfig{}, nil
}
return parseBranchConfig(outputLines(out)), nil
}
func parseBranchConfig(configLines []string) BranchConfig {
var cfg BranchConfig
for _, line := range configLines {
parts := strings.SplitN(line, " ", 2)
if len(parts) < 2 {
continue
}
keys := strings.Split(parts[0], ".")
switch keys[len(keys)-1] {
case "remote":
if strings.Contains(parts[1], ":") {
u, err := ParseURL(parts[1])
if err != nil {
continue
}
cfg.RemoteURL = u
} else if !isFilesystemPath(parts[1]) {
cfg.RemoteName = parts[1]
}
case "merge":
cfg.MergeRef = parts[1]
case MergeBaseConfig:
cfg.MergeBase = parts[1]
}
}
return cfg
}
// SetBranchConfig sets the named value on the given branch.
func (c *Client) SetBranchConfig(ctx context.Context, branch, name, value string) error {
name = fmt.Sprintf("branch.%s.%s", branch, name)
args := []string{"config", name, value}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
// No output expected but check for any printed git error.
_, err = cmd.Output()
return err
}
func (c *Client) DeleteLocalTag(ctx context.Context, tag string) error {
args := []string{"tag", "-d", tag}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) DeleteLocalBranch(ctx context.Context, branch string) error {
args := []string{"branch", "-D", branch}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) CheckoutBranch(ctx context.Context, branch string) error {
args := []string{"checkout", branch}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) CheckoutNewBranch(ctx context.Context, remoteName, branch string) error {
track := fmt.Sprintf("%s/%s", remoteName, branch)
args := []string{"checkout", "-b", branch, "--track", track}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) HasLocalBranch(ctx context.Context, branch string) bool {
_, err := c.revParse(ctx, "--verify", "refs/heads/"+branch)
return err == nil
}
func (c *Client) TrackingBranchNames(ctx context.Context, prefix string) []string {
args := []string{"branch", "-r", "--format", "%(refname:strip=3)"}
if prefix != "" {
args = append(args, "--list", fmt.Sprintf("*/%s*", escapeGlob(prefix)))
}
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil
}
output, err := cmd.Output()
if err != nil {
return nil
}
return strings.Split(string(output), "\n")
}
// ToplevelDir returns the top-level directory path of the current repository.
func (c *Client) ToplevelDir(ctx context.Context) (string, error) {
out, err := c.revParse(ctx, "--show-toplevel")
if err != nil {
return "", err
}
return firstLine(out), nil
}
func (c *Client) GitDir(ctx context.Context) (string, error) {
out, err := c.revParse(ctx, "--git-dir")
if err != nil {
return "", err
}
return firstLine(out), nil
}
// Show current directory relative to the top-level directory of repository.
func (c *Client) PathFromRoot(ctx context.Context) string {
out, err := c.revParse(ctx, "--show-prefix")
if err != nil {
return ""
}
if path := firstLine(out); path != "" {
return path[:len(path)-1]
}
return ""
}
func (c *Client) revParse(ctx context.Context, args ...string) ([]byte, error) {
args = append([]string{"rev-parse"}, args...)
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil, err
}
return cmd.Output()
}
func (c *Client) IsLocalGitRepo(ctx context.Context) (bool, error) {
_, err := c.GitDir(ctx)
if err != nil {
var execError errWithExitCode
if errors.As(err, &execError) && execError.ExitCode() == 128 {
return false, nil
}
return false, err
}
return true, nil
}
func (c *Client) UnsetRemoteResolution(ctx context.Context, name string) error {
args := []string{"config", "--unset", fmt.Sprintf("remote.%s.gh-resolved", name)}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) SetRemoteBranches(ctx context.Context, remote string, refspec string) error {
args := []string{"remote", "set-branches", remote, refspec}
cmd, err := c.Command(ctx, args...)
if err != nil {
return err
}
_, err = cmd.Output()
if err != nil {
return err
}
return nil
}
func (c *Client) AddRemote(ctx context.Context, name, urlStr string, trackingBranches []string) (*Remote, error) {
args := []string{"remote", "add"}
for _, branch := range trackingBranches {
args = append(args, "-t", branch)
}
args = append(args, name, urlStr)
cmd, err := c.Command(ctx, args...)
if err != nil {
return nil, err
}
if _, err := cmd.Output(); err != nil {
return nil, err
}
var urlParsed *url.URL
if strings.HasPrefix(urlStr, "https") {
urlParsed, err = url.Parse(urlStr)
if err != nil {
return nil, err
}
} else {
urlParsed, err = ParseURL(urlStr)
if err != nil {
return nil, err
}
}
remote := &Remote{
Name: name,
FetchURL: urlParsed,
PushURL: urlParsed,
}
return remote, nil
}
// Below are commands that make network calls and need authentication credentials supplied from gh.
func (c *Client) Fetch(ctx context.Context, remote string, refspec string, mods ...CommandModifier) error {
args := []string{"fetch", remote}
if refspec != "" {
args = append(args, refspec)
}
cmd, err := c.AuthenticatedCommand(ctx, AllMatchingCredentialsPattern, args...)
if err != nil {
return err
}
for _, mod := range mods {
mod(cmd)
}
return cmd.Run()
}
func (c *Client) Pull(ctx context.Context, remote, branch string, mods ...CommandModifier) error {
args := []string{"pull", "--ff-only"}
if remote != "" && branch != "" {
args = append(args, remote, branch)
}
cmd, err := c.AuthenticatedCommand(ctx, AllMatchingCredentialsPattern, args...)
if err != nil {
return err
}
for _, mod := range mods {
mod(cmd)
}
return cmd.Run()
}
func (c *Client) Push(ctx context.Context, remote string, ref string, mods ...CommandModifier) error {
args := []string{"push", "--set-upstream", remote, ref}
cmd, err := c.AuthenticatedCommand(ctx, AllMatchingCredentialsPattern, args...)
if err != nil {
return err
}
for _, mod := range mods {
mod(cmd)
}
return cmd.Run()
}
func (c *Client) Clone(ctx context.Context, cloneURL string, args []string, mods ...CommandModifier) (string, error) {
// Note that even if this is an SSH clone URL, we are setting the pattern anyway.
// We could write some code to prevent this, but it also doesn't seem harmful.
pattern, err := CredentialPatternFromGitURL(cloneURL)
if err != nil {
return "", err
}
cloneArgs, target := parseCloneArgs(args)
cloneArgs = append(cloneArgs, cloneURL)
// If the args contain an explicit target, pass it to clone otherwise,
// parse the URL to determine where git cloned it to so we can return it.
if target != "" {
cloneArgs = append(cloneArgs, target)
} else {
target = path.Base(strings.TrimSuffix(cloneURL, ".git"))
if slices.Contains(cloneArgs, "--bare") {
target += ".git"
}
}
cloneArgs = append([]string{"clone"}, cloneArgs...)
cmd, err := c.AuthenticatedCommand(ctx, pattern, cloneArgs...)
if err != nil {
return "", err
}
for _, mod := range mods {
mod(cmd)
}
err = cmd.Run()
if err != nil {
return "", err
}
return target, nil
}
func resolveGitPath() (string, error) {
path, err := safeexec.LookPath("git")
if err != nil {
if errors.Is(err, exec.ErrNotFound) {
programName := "git"
if runtime.GOOS == "windows" {
programName = "Git for Windows"
}
return "", &NotInstalled{
message: fmt.Sprintf("unable to find git executable in PATH; please install %s before retrying", programName),
err: err,
}
}
return "", err
}
return path, nil
}
func isFilesystemPath(p string) bool {
return p == "." || strings.HasPrefix(p, "./") || strings.HasPrefix(p, "/")
}
func outputLines(output []byte) []string {
lines := strings.TrimSuffix(string(output), "\n")
return strings.Split(lines, "\n")
}
func firstLine(output []byte) string {
if i := bytes.IndexAny(output, "\n"); i >= 0 {
return string(output)[0:i]
}
return string(output)
}
func parseCloneArgs(extraArgs []string) (args []string, target string) {
args = extraArgs
if len(args) > 0 {
if !strings.HasPrefix(args[0], "-") {
target, args = args[0], args[1:]
}
}
return
}
func parseRemotes(remotesStr []string) RemoteSet {
remotes := RemoteSet{}
for _, r := range remotesStr {
match := remoteRE.FindStringSubmatch(r)
if match == nil {
continue
}
name := strings.TrimSpace(match[1])
urlStr := strings.TrimSpace(match[2])
urlType := strings.TrimSpace(match[3])
url, err := ParseURL(urlStr)
if err != nil {
continue
}
var rem *Remote
if len(remotes) > 0 {
rem = remotes[len(remotes)-1]
if name != rem.Name {
rem = nil
}
}
if rem == nil {
rem = &Remote{Name: name}
remotes = append(remotes, rem)
}
switch urlType {
case "fetch":
rem.FetchURL = url
case "push":
rem.PushURL = url
}
}
return remotes
}
func populateResolvedRemotes(remotes RemoteSet, resolved []string) {
for _, l := range resolved {
parts := strings.SplitN(l, " ", 2)
if len(parts) < 2 {
continue
}
rp := strings.SplitN(parts[0], ".", 3)
if len(rp) < 2 {
continue
}
name := rp[1]
for _, r := range remotes {
if r.Name == name {
r.Resolved = parts[1]
break
}
}
}
}
var globReplacer = strings.NewReplacer(
"*", `\*`,
"?", `\?`,
"[", `\[`,
"]", `\]`,
"{", `\{`,
"}", `\}`,
)
func escapeGlob(p string) string {
return globReplacer.Replace(p)
}