package diff
import (
"bufio"
"errors"
"fmt"
"io"
"net/http"
"strings"
"syscall"
"github.com/MakeNowJust/heredoc"
"github.com/cli/cli/v2/api"
"github.com/cli/cli/v2/pkg/cmd/pr/shared"
"github.com/cli/cli/v2/pkg/cmdutil"
"github.com/cli/cli/v2/pkg/iostreams"
"github.com/spf13/cobra"
)
type DiffOptions struct {
HttpClient func() (*http.Client, error)
IO *iostreams.IOStreams
Finder shared.PRFinder
SelectorArg string
UseColor string
}
func NewCmdDiff(f *cmdutil.Factory, runF func(*DiffOptions) error) *cobra.Command {
opts := &DiffOptions{
IO: f.IOStreams,
HttpClient: f.HttpClient,
}
cmd := &cobra.Command{
Use: "diff [ | | ]",
Short: "View changes in a pull request",
Long: heredoc.Doc(`
View changes in a pull request.
Without an argument, the pull request that belongs to the current branch
is selected.
`),
Args: cobra.MaximumNArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
opts.Finder = shared.NewFinder(f)
if repoOverride, _ := cmd.Flags().GetString("repo"); repoOverride != "" && len(args) == 0 {
return &cmdutil.FlagError{Err: errors.New("argument required when using the --repo flag")}
}
if len(args) > 0 {
opts.SelectorArg = args[0]
}
if !validColorFlag(opts.UseColor) {
return &cmdutil.FlagError{Err: fmt.Errorf("did not understand color: %q. Expected one of always, never, or auto", opts.UseColor)}
}
if opts.UseColor == "auto" && !opts.IO.IsStdoutTTY() {
opts.UseColor = "never"
}
if runF != nil {
return runF(opts)
}
return diffRun(opts)
},
}
cmd.Flags().StringVar(&opts.UseColor, "color", "auto", "Use color in diff output: {always|never|auto}")
return cmd
}
func diffRun(opts *DiffOptions) error {
findOptions := shared.FindOptions{
Selector: opts.SelectorArg,
Fields: []string{"number"},
}
pr, baseRepo, err := opts.Finder.Find(findOptions)
if err != nil {
return err
}
httpClient, err := opts.HttpClient()
if err != nil {
return err
}
apiClient := api.NewClientFromHTTP(httpClient)
diff, err := apiClient.PullRequestDiff(baseRepo, pr.Number)
if err != nil {
return fmt.Errorf("could not find pull request diff: %w", err)
}
defer diff.Close()
err = opts.IO.StartPager()
if err != nil {
return err
}
defer opts.IO.StopPager()
if opts.UseColor == "never" {
_, err = io.Copy(opts.IO.Out, diff)
if errors.Is(err, syscall.EPIPE) {
return nil
}
return err
}
diffLines := bufio.NewScanner(diff)
for diffLines.Scan() {
diffLine := diffLines.Text()
switch {
case isHeaderLine(diffLine):
fmt.Fprintf(opts.IO.Out, "\x1b[1;38m%s\x1b[m\n", diffLine)
case isAdditionLine(diffLine):
fmt.Fprintf(opts.IO.Out, "\x1b[32m%s\x1b[m\n", diffLine)
case isRemovalLine(diffLine):
fmt.Fprintf(opts.IO.Out, "\x1b[31m%s\x1b[m\n", diffLine)
default:
fmt.Fprintln(opts.IO.Out, diffLine)
}
}
if err := diffLines.Err(); err != nil {
return fmt.Errorf("error reading pull request diff: %w", err)
}
return nil
}
var diffHeaderPrefixes = []string{"+++", "---", "diff", "index"}
func isHeaderLine(dl string) bool {
for _, p := range diffHeaderPrefixes {
if strings.HasPrefix(dl, p) {
return true
}
}
return false
}
func isAdditionLine(dl string) bool {
return strings.HasPrefix(dl, "+")
}
func isRemovalLine(dl string) bool {
return strings.HasPrefix(dl, "-")
}
func validColorFlag(c string) bool {
return c == "auto" || c == "always" || c == "never"
}