Added asciidoc generation and associated tests.

doc/README.md

@@ -1,5 +1,6 @@
 # Documentation generation
 
+- [Asciidoc docs](./asciidoc_docs.md)
 - [Man page docs](./man_docs.md)
 - [Markdown docs](./md_docs.md)
 - [Rest docs](./rest_docs.md)

doc/asciidoc_docs.go

@@ -0,0 +1,172 @@
+package doc
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/spf13/cobra"
+)
+
+func printOptionsAsciidoc(buf *bytes.Buffer, cmd *cobra.Command, name string) error {
+	flags := cmd.NonInheritedFlags()
+	flags.SetOutput(buf)
+	if flags.HasAvailableFlags() {
+		buf.WriteString("== Options\n")
+		buf.WriteString("\n")
+		buf.WriteString(".Options\n")
+		buf.WriteString("[source,text]\n----\n")
+		flags.PrintDefaults()
+		buf.WriteString("----\n\n")
+	}
+
+	parentFlags := cmd.InheritedFlags()
+	parentFlags.SetOutput(buf)
+	if parentFlags.HasAvailableFlags() {
+		buf.WriteString("== Options inherited from parent commands\n\n")
+		buf.WriteString(".Parent Options\n")
+		buf.WriteString("[source,text]\n----\n")
+		parentFlags.PrintDefaults()
+		buf.WriteString("----\n\n")
+	}
+	return nil
+}
+
+// GenAsciidoc creates Asciidoc output.
+func GenAsciidoc(cmd *cobra.Command, w io.Writer) error {
+	return GenAsciidocCustom(cmd, w, func(s string) string { return s })
+}
+
+// GenAsciidocCustom creates custom Asciidoc output.
+func GenAsciidocCustom(cmd *cobra.Command, w io.Writer, linkHandler func(string) string) error {
+	cmd.InitDefaultHelpCmd()
+	cmd.InitDefaultHelpFlag()
+
+	buf := new(bytes.Buffer)
+	name := cmd.CommandPath()
+	splitName := strings.Split(cmd.CommandPath(), " ")
+
+	if len(splitName) < 2 {
+		buf.WriteString("= " + name + "\n\n")
+	} else {
+		buf.WriteString("= " + splitName[0] + ":")
+		for index, cmdName := range splitName {
+			if index < 1 {
+				// Skip the root name.
+				continue
+			}
+			buf.WriteString(" " + cmdName)
+		}
+		buf.WriteString("\n\n")
+	}
+	// No point in printing the description if it's empty.
+	if len(cmd.Short) > 0 {
+		buf.WriteString("[.lead]\n")
+		buf.WriteString(cmd.Short + "\n\n")
+	}
+
+	if len(cmd.Long) > 0 {
+		buf.WriteString("== Synopsis\n\n")
+		buf.WriteString(cmd.Long + "\n\n")
+	}
+
+	if cmd.Runnable() {
+		buf.WriteString(fmt.Sprintf("[source,text]\n"))
+		buf.WriteString(fmt.Sprintf("----\n%s\n----\n\n", cmd.UseLine()))
+	}
+
+	if len(cmd.Example) > 0 {
+		buf.WriteString("== Examples\n\n")
+		buf.WriteString(".Examples Options\n")
+		buf.WriteString("[source,text]\n")
+		buf.WriteString(fmt.Sprintf("----\n%s\n----\n\n", cmd.Example))
+	}
+
+	if err := printOptionsAsciidoc(buf, cmd, name); err != nil {
+		return err
+	}
+	if hasSeeAlso(cmd) {
+		buf.WriteString(fmt.Sprintf("== SEE ALSO\n\n"))
+		if cmd.HasParent() {
+			parent := cmd.Parent()
+			pname := parent.CommandPath()
+			link := pname + ".adoc"
+			link = strings.ReplaceAll(link, " ", "_")
+			buf.WriteString(fmt.Sprintf("* xref:%s[%s]\t - %s\n", linkHandler(link), pname, parent.Short))
+			cmd.VisitParents(func(c *cobra.Command) {
+				if c.DisableAutoGenTag {
+					cmd.DisableAutoGenTag = c.DisableAutoGenTag
+				}
+			})
+		}
+
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+
+		for _, child := range children {
+			if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			cname := name + " " + child.Name()
+			link := cname + ".adoc"
+			link = strings.ReplaceAll(link, " ", "_")
+			buf.WriteString(fmt.Sprintf("* xref:%s[%s]\t - %s\n", linkHandler(link), cname, child.Short))
+		}
+		buf.WriteString("\n")
+	}
+	if !cmd.DisableAutoGenTag {
+
+		buf.WriteString("\n.Last Generated\n")
+		buf.WriteString("****\n")
+		buf.WriteString("Auto generated by spf13/cobra on " + time.Now().Format("2-Jan-2006") + "\n")
+		buf.WriteString("****\n")
+	}
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+// GenAsciidocTree will generate a Asciidoc page for this command and all
+// descendants in the directory given. The header may be nil.
+// This function may not work correctly if your command names have `-` in them.
+// If you have `cmd` with two subcmds, `sub` and `sub-third`,
+// and `sub` has a subcommand called `third`, it is undefined which
+// help output will be in the file `cmd-sub-third.1`.
+func GenAsciidocTree(cmd *cobra.Command, dir string) error {
+	identity := func(s string) string { return s }
+	emptyStr := func(s string) string { return "" }
+	return GenAsciidocTreeCustom(cmd, dir, emptyStr, identity)
+}
+
+// GenAsciidocTreeCustom is the the same as GenAsciidocTree, but
+// with custom filePrepender and linkHandler.
+func GenAsciidocTreeCustom(cmd *cobra.Command, dir string, filePrepender, linkHandler func(string) string) error {
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		if err := GenAsciidocTreeCustom(c, dir, filePrepender, linkHandler); err != nil {
+			return err
+		}
+	}
+
+	basename := strings.ReplaceAll(cmd.CommandPath(), " ", "_") + ".adoc"
+	filename := filepath.Join(dir, basename)
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if _, err := io.WriteString(f, filePrepender(filename)); err != nil {
+		return err
+	}
+	if err := GenAsciidocCustom(cmd, f, linkHandler); err != nil {
+		return err
+	}
+	return nil
+}

doc/asciidoc_docs.md

@@ -0,0 +1,115 @@
+# Generating Asciidoc Docs For Your Own cobra.Command
+
+Generating Asciidoc pages from a cobra command is incredibly easy. An example is as follows:
+
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/cobra/doc"
+)
+
+func main() {
+	cmd := &cobra.Command{
+		Use:   "test",
+		Short: "my test program",
+	}
+	err := doc.GenAsciidocTree(cmd, "/tmp")
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+```
+
+That will get you a Asciidoc document `/tmp/test.adoc`
+
+## Generate Asciidoc docs for the entire command tree
+
+This program could generate docs for the kubectl command in the kubernetes project
+
+```go
+package main
+
+import (
+	"log"
+	"io/ioutil"
+	"os"
+
+	"k8s.io/kubernetes/pkg/kubectl/cmd"
+	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
+
+	"github.com/spf13/cobra/doc"
+)
+
+func main() {
+	kubectl := cmd.NewKubectlCommand(cmdutil.NewFactory(nil), os.Stdin, ioutil.Discard, ioutil.Discard)
+	err := doc.GenAsciidocTree(kubectl, "./")
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+```
+
+This will generate a whole series of files, one for each command in the tree, in the directory specified (in this case "./")
+
+## Generate Asciidoc docs for a single command
+
+You may wish to have more control over the output, or only generate for a single command, instead of the entire command tree. If this is the case you may prefer to `GenAsciidoc` instead of `GenAsciidocTree`
+
+```go
+	out := new(bytes.Buffer)
+	err := doc.GenAsciidoc(cmd, out)
+	if err != nil {
+		log.Fatal(err)
+	}
+```
+
+This will write the Asciidoc doc for ONLY "cmd" into the out, buffer.
+
+## Customize the output
+
+Both `GenAsciidoc` and `GenAsciidocTree` have alternate versions with callbacks to get some control of the output:
+
+```go
+func GenAsciidocTreeCustom(cmd *Command, dir string, filePrepender, linkHandler func(string) string) error {
+	//...
+}
+```
+
+```go
+func GenAsciidocCustom(cmd *Command, out *bytes.Buffer, linkHandler func(string) string) error {
+	//...
+}
+```
+
+The `filePrepender` will prepend the return value given the full filepath to the rendered Asciidoc file. A common use case is to add front matter to use the generated documentation with [Hugo](http://gohugo.io/):
+
+```go
+const fmTemplate = `---
+date: %s
+title: "%s"
+slug: %s
+url: %s
+---
+`
+
+filePrepender := func(filename string) string {
+	now := time.Now().Format(time.RFC3339)
+	name := filepath.Base(filename)
+	base := strings.TrimSuffix(name, path.Ext(name))
+	url := "/commands/" + strings.ToLower(base) + "/"
+	return fmt.Sprintf(fmTemplate, now, strings.Replace(base, "_", " ", -1), base, url)
+}
+```
+
+The `linkHandler` can be used to customize the rendered internal links to the commands, given a filename:
+
+```go
+linkHandler := func(name string) string {
+	base := strings.TrimSuffix(name, path.Ext(name))
+	return "/commands/" + strings.ToLower(base) + "/"
+}
+```