2022-11-16 10:33:57PM

cmd/d2/help.go

@@ -28,7 +28,7 @@ Subcommands:
   %[1]s layout [layout name] - Display long help for a particular layout engine
 
 See more docs and the source code at https://oss.terrastruct.com/d2
-`, ms.Name, ms.Opts.Help())
+`, ms.Name, ms.Opts.Defaults())
 }
 
 func layoutHelp(ctx context.Context, ms *xmain.State) error {

lib/xmain/flag_helpers.go

@@ -0,0 +1,45 @@
+// flag_helpers.go are private functions from pflag/flag.go
+package xmain
+
+import "strings"
+
+func wrap(i, w int, s string) string {
+	if w == 0 {
+		return strings.Replace(s, "\n", "\n"+strings.Repeat(" ", i), -1)
+	}
+	wrap := w - i
+	var r, l string
+	if wrap < 24 {
+		i = 16
+		wrap = w - i
+		r += "\n" + strings.Repeat(" ", i)
+	}
+	if wrap < 24 {
+		return strings.Replace(s, "\n", r, -1)
+	}
+	slop := 5
+	wrap = wrap - slop
+	l, s = wrapN(wrap, slop, s)
+	r = r + strings.Replace(l, "\n", "\n"+strings.Repeat(" ", i), -1)
+	for s != "" {
+		var t string
+		t, s = wrapN(wrap, slop, s)
+		r = r + "\n" + strings.Repeat(" ", i) + strings.Replace(t, "\n", "\n"+strings.Repeat(" ", i), -1)
+	}
+	return r
+}
+
+func wrapN(i, slop int, s string) (string, string) {
+	if i+slop > len(s) {
+		return s, ""
+	}
+	w := strings.LastIndexAny(s[:i], " \t\n")
+	if w <= 0 {
+		return s, ""
+	}
+	nlPos := strings.LastIndex(s[:i], "\n")
+	if nlPos > 0 && nlPos < w {
+		return s[:nlPos], s[nlPos+1:]
+	}
+	return s[:w], s[w+1:]
+}

lib/xmain/opts.go

@@ -1,6 +1,7 @@
 package xmain
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"strconv"
@@ -17,7 +18,7 @@ type Opts struct {
 	env   *xos.Env
 	log   *cmdlog.Logger
 
-	registeredEnvs []string
+	flagEnv map[string]string
 }
 
 func NewOpts(env *xos.Env, log *cmdlog.Logger, args []string) *Opts {
@@ -26,42 +27,106 @@ func NewOpts(env *xos.Env, log *cmdlog.Logger, args []string) *Opts {
 	flags.Usage = func() {}
 	flags.SetOutput(io.Discard)
 	return &Opts{
-		Args:  args,
-		Flags: flags,
-		env:   env,
-		log:   log,
+		Args:    args,
+		Flags:   flags,
+		env:     env,
+		log:     log,
+		flagEnv: make(map[string]string),
 	}
 }
 
-func (o *Opts) Help() string {
-	b := &strings.Builder{}
-	o.Flags.SetOutput(b)
-	o.Flags.PrintDefaults()
+// Mostly copy pasted pasted from pflag.FlagUsagesWrapped
+// with modifications for env var
+func (o *Opts) Defaults() string {
+	buf := new(bytes.Buffer)
 
-	if len(o.registeredEnvs) > 0 {
-		b.WriteString("\nYou may persistently set the following as environment variables (flags take precedent):\n")
-		for i, e := range o.registeredEnvs {
-			s := fmt.Sprintf("- $%s", e)
-			if i != len(o.registeredEnvs)-1 {
-				s += "\n"
-			}
-			b.WriteString(s)
+	var lines []string
+
+	maxlen := 0
+	maxEnvLen := 0
+	o.Flags.VisitAll(func(flag *pflag.Flag) {
+		if flag.Hidden {
+			return
 		}
+
+		line := ""
+		if flag.Shorthand != "" && flag.ShorthandDeprecated == "" {
+			line = fmt.Sprintf("  -%s, --%s", flag.Shorthand, flag.Name)
+		} else {
+			line = fmt.Sprintf("      --%s", flag.Name)
+		}
+
+		varname, usage := pflag.UnquoteUsage(flag)
+		if varname != "" {
+			line += " " + varname
+		}
+		if flag.NoOptDefVal != "" {
+			switch flag.Value.Type() {
+			case "string":
+				line += fmt.Sprintf("[=\"%s\"]", flag.NoOptDefVal)
+			case "bool":
+				if flag.NoOptDefVal != "true" {
+					line += fmt.Sprintf("[=%s]", flag.NoOptDefVal)
+				}
+			case "count":
+				if flag.NoOptDefVal != "+1" {
+					line += fmt.Sprintf("[=%s]", flag.NoOptDefVal)
+				}
+			default:
+				line += fmt.Sprintf("[=%s]", flag.NoOptDefVal)
+			}
+		}
+
+		line += "\x00"
+
+		if len(line) > maxlen {
+			maxlen = len(line)
+		}
+
+		if e, ok := o.flagEnv[flag.Name]; ok {
+			line += fmt.Sprintf("$%s", e)
+		}
+
+		line += "\x01"
+
+		if len(line) > maxEnvLen {
+			maxEnvLen = len(line)
+		}
+
+		line += usage
+		if flag.Value.Type() == "string" {
+			line += fmt.Sprintf(" (default %q)", flag.DefValue)
+		} else {
+			line += fmt.Sprintf(" (default %s)", flag.DefValue)
+		}
+		if len(flag.Deprecated) != 0 {
+			line += fmt.Sprintf(" (DEPRECATED: %s)", flag.Deprecated)
+		}
+
+		lines = append(lines, line)
+	})
+
+	for _, line := range lines {
+		sidx1 := strings.Index(line, "\x00")
+		sidx2 := strings.Index(line, "\x01")
+		spacing1 := strings.Repeat(" ", maxlen-sidx1)
+		spacing2 := strings.Repeat(" ", (maxEnvLen-maxlen)-sidx2+sidx1)
+		fmt.Fprintln(buf, line[:sidx1], spacing1, line[sidx1+1:sidx2], spacing2, wrap(maxEnvLen+3, 0, line[sidx2+1:]))
 	}
 
-	return b.String()
+	return buf.String()
 }
 
-func (o *Opts) getEnv(k string) string {
+func (o *Opts) getEnv(flag, k string) string {
 	if k != "" {
-		o.registeredEnvs = append(o.registeredEnvs, k)
+		o.flagEnv[flag] = k
 		return o.env.Getenv(k)
 	}
 	return ""
 }
 
 func (o *Opts) Int64(envKey, flag, shortFlag string, defaultVal int64, usage string) (*int64, error) {
-	if env := o.getEnv(envKey); env != "" {
+	if env := o.getEnv(flag, envKey); env != "" {
 		envVal, err := strconv.ParseInt(env, 10, 64)
 		if err != nil {
 			return nil, fmt.Errorf(`invalid environment variable %s. Expected int64. Found "%v".`, envKey, envVal)
@@ -73,7 +138,7 @@ func (o *Opts) Int64(envKey, flag, shortFlag string, defaultVal int64, usage str
 }
 
 func (o *Opts) String(envKey, flag, shortFlag string, defaultVal, usage string) *string {
-	if env := o.getEnv(envKey); env != "" {
+	if env := o.getEnv(flag, envKey); env != "" {
 		defaultVal = env
 	}
 
@@ -81,7 +146,7 @@ func (o *Opts) String(envKey, flag, shortFlag string, defaultVal, usage string)
 }
 
 func (o *Opts) Bool(envKey, flag, shortFlag string, defaultVal bool, usage string) (*bool, error) {
-	if env := o.getEnv(envKey); env != "" {
+	if env := o.getEnv(flag, envKey); env != "" {
 		if !boolyEnv(env) {
 			return nil, fmt.Errorf(`invalid environment variable %s. Expected bool. Found "%s".`, envKey, env)
 		}