cmd/doc: boiler plate and for inputs / outputs scanning

Signed-off-by: Sam Alba <sam.alba@gmail.com>

cmd/dagger/cmd/doc.go

@@ -0,0 +1,144 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+
+	"cuelang.org/go/cue"
+	"cuelang.org/go/cue/format"
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"go.dagger.io/dagger/cmd/dagger/cmd/common"
+	"go.dagger.io/dagger/cmd/dagger/logger"
+	"go.dagger.io/dagger/compiler"
+	"go.dagger.io/dagger/environment"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+const (
+	textFormat     = "txt"
+	markdownFormat = "md"
+)
+
+var docCmd = &cobra.Command{
+	Use:   "doc [PACKAGE | PATH]",
+	Short: "document a package",
+	Args:  cobra.MaximumNArgs(1),
+	PreRun: func(cmd *cobra.Command, args []string) {
+		// Fix Viper bug for duplicate flags:
+		// https://github.com/spf13/viper/issues/233
+		if err := viper.BindPFlags(cmd.Flags()); err != nil {
+			panic(err)
+		}
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		lg := logger.New()
+		ctx := lg.WithContext(cmd.Context())
+		workspace := common.CurrentWorkspace(ctx)
+		st := common.CurrentEnvironmentState(ctx, workspace)
+
+		format := viper.GetString("output")
+		if format != textFormat && format != markdownFormat {
+			lg.Fatal().Msg("output must be either `txt` or `md`")
+		}
+
+		val, err := loadCode(args[0])
+		if err != nil {
+			lg.Fatal().Err(err).Msg("cannot compile code")
+		}
+		PrintDoc(ctx, val, format)
+	},
+}
+
+func init() {
+	docCmd.Flags().StringP("output", "o", textFormat, "Output format (txt|md)")
+
+	if err := viper.BindPFlags(docCmd.Flags()); err != nil {
+		panic(err)
+	}
+}
+
+func extractComment(v cue.Value) string {
+	docs := []string{}
+	for _, c := range v.Doc() {
+		docs = append(docs, strings.TrimSpace(c.Text()))
+	}
+	doc := strings.Join(docs, " ")
+
+	lines := strings.Split(doc, "\n")
+
+	// Strip out FIXME, TODO, and INTERNAL comments
+	docs = []string{}
+	for _, line := range lines {
+		if strings.HasPrefix(line, "FIXME: ") ||
+			strings.HasPrefix(line, "TODO: ") ||
+			strings.HasPrefix(line, "INTERNAL: ") {
+			continue
+		}
+		docs = append(docs, line)
+	}
+	return strings.Join(docs, " ")
+}
+
+func extractSpec(v cue.Value) string {
+	node := v.Source()
+	if node == nil {
+		return fmt.Sprintf("%v", v)
+	}
+	src, err := format.Node(node)
+	if err != nil {
+		panic(err)
+	}
+	space := regexp.MustCompile(`[\s\n]+`)
+	return strings.TrimSpace(
+		space.ReplaceAllString(string(src), " "),
+	)
+}
+
+func mdEscape(s string) string {
+	escape := []string{"|", "<", ">"}
+	for _, c := range escape {
+		s = strings.ReplaceAll(s, c, `\`+c)
+	}
+	return s
+}
+
+func terminalTrim(msg string) string {
+	// If we're not running on a terminal, return the whole string
+	size, _, err := terminal.GetSize(1)
+	if err != nil {
+		return msg
+	}
+
+	// Otherwise, trim to fit half the terminal
+	size /= 2
+	for utf8.RuneCountInString(msg) > size {
+		msg = msg[0:len(msg)-4] + "…"
+	}
+	return msg
+}
+
+func loadCode(path string) (*compiler.Value, error) {
+	src, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	val, err := compiler.Compile("", string(src))
+	if err != nil {
+		return nil, err
+	}
+
+	return val, nil
+}
+
+func PrintDoc(ctx context.Context, val *compiler.Value, format string) {
+	lg := log.Ctx(ctx)
+
+	environment.ScanOutputs(ctx, val)
+}

cmd/dagger/cmd/root.go

@@ -46,6 +46,7 @@ func init() {
 		input.Cmd,
 		output.Cmd,
 		versionCmd,
+		docCmd,
 	)
 
 	if err := viper.BindPFlags(rootCmd.PersistentFlags()); err != nil {