Started working on Unified API for the various shell completions:

- Moved some general function to a more generic shell_completions file.
- Added functions to mark flag as directory completion.
- Started making the global functions docs more generic (not bash
  specific) and added compatibility matrix.

bash_completions.go

@@ -545,51 +545,3 @@ func (c *Command) GenBashCompletionFile(filename string) error {
 
 	return c.GenBashCompletion(outFile)
 }
-
-// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
-// and causes your command to report an error if invoked without the flag.
-func (c *Command) MarkFlagRequired(name string) error {
-	return MarkFlagRequired(c.Flags(), name)
-}
-
-// MarkPersistentFlagRequired adds the BashCompOneRequiredFlag annotation to the named persistent flag if it exists,
-// and causes your command to report an error if invoked without the flag.
-func (c *Command) MarkPersistentFlagRequired(name string) error {
-	return MarkFlagRequired(c.PersistentFlags(), name)
-}
-
-// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
-// and causes your command to report an error if invoked without the flag.
-func MarkFlagRequired(flags *pflag.FlagSet, name string) error {
-	return flags.SetAnnotation(name, BashCompOneRequiredFlag, []string{"true"})
-}
-
-// MarkFlagFilename adds the BashCompFilenameExt annotation to the named flag, if it exists.
-// Generated bash autocompletion will select filenames for the flag, limiting to named extensions if provided.
-func (c *Command) MarkFlagFilename(name string, extensions ...string) error {
-	return MarkFlagFilename(c.Flags(), name, extensions...)
-}
-
-// MarkFlagCustom adds the BashCompCustom annotation to the named flag, if it exists.
-// Generated bash autocompletion will call the bash function f for the flag.
-func (c *Command) MarkFlagCustom(name string, f string) error {
-	return MarkFlagCustom(c.Flags(), name, f)
-}
-
-// MarkPersistentFlagFilename adds the BashCompFilenameExt annotation to the named persistent flag, if it exists.
-// Generated bash autocompletion will select filenames for the flag, limiting to named extensions if provided.
-func (c *Command) MarkPersistentFlagFilename(name string, extensions ...string) error {
-	return MarkFlagFilename(c.PersistentFlags(), name, extensions...)
-}
-
-// MarkFlagFilename adds the BashCompFilenameExt annotation to the named flag in the flag set, if it exists.
-// Generated bash autocompletion will select filenames for the flag, limiting to named extensions if provided.
-func MarkFlagFilename(flags *pflag.FlagSet, name string, extensions ...string) error {
-	return flags.SetAnnotation(name, BashCompFilenameExt, extensions)
-}
-
-// MarkFlagCustom adds the BashCompCustom annotation to the named flag in the flag set, if it exists.
-// Generated bash autocompletion will call the bash function f for the flag.
-func MarkFlagCustom(flags *pflag.FlagSet, name string, f string) error {
-	return flags.SetAnnotation(name, BashCompCustom, []string{f})
-}

shell_completions.go

@@ -0,0 +1,85 @@
+package cobra
+
+import (
+	"github.com/spf13/pflag"
+)
+
+// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
+// and causes your command to report an error if invoked without the flag.
+func (c *Command) MarkFlagRequired(name string) error {
+	return MarkFlagRequired(c.Flags(), name)
+}
+
+// MarkPersistentFlagRequired adds the BashCompOneRequiredFlag annotation to the named persistent flag if it exists,
+// and causes your command to report an error if invoked without the flag.
+func (c *Command) MarkPersistentFlagRequired(name string) error {
+	return MarkFlagRequired(c.PersistentFlags(), name)
+}
+
+// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
+// and causes your command to report an error if invoked without the flag.
+func MarkFlagRequired(flags *pflag.FlagSet, name string) error {
+	return flags.SetAnnotation(name, BashCompOneRequiredFlag, []string{"true"})
+}
+
+// MarkFlagFilename adds the BashCompFilenameExt annotation to the named flag, if it exists.
+// Generated bash autocompletion will select filenames for the flag, limiting to named extensions if provided.
+func (c *Command) MarkFlagFilename(name string, extensions ...string) error {
+	return MarkFlagFilename(c.Flags(), name, extensions...)
+}
+
+// MarkFlagCustom adds the BashCompCustom annotation to the named flag, if it exists.
+// Generated bash autocompletion will call the bash function f for the flag.
+func (c *Command) MarkFlagCustom(name string, f string) error {
+	return MarkFlagCustom(c.Flags(), name, f)
+}
+
+// MarkPersistentFlagFilename instructs the various shell completion
+// implementations to limit completions for this persistent flag to the
+// specified extensions (patterns).
+//
+// Shell Completion compatibility matrix: bash, zsh
+func (c *Command) MarkPersistentFlagFilename(name string, extensions ...string) error {
+	return MarkFlagFilename(c.PersistentFlags(), name, extensions...)
+}
+
+// MarkFlagFilename instructs the various shell completion implementations to
+// limit completions for this flag to the specified extensions (patterns).
+//
+// Shell Completion compatibility matrix: bash, zsh
+func MarkFlagFilename(flags *pflag.FlagSet, name string, extensions ...string) error {
+	return flags.SetAnnotation(name, BashCompFilenameExt, extensions)
+}
+
+// MarkFlagCustom instructs the various shell completion implementations to
+// limit completions for this flag to the specified extensions (patterns).
+//
+// Shell Completion compatibility matrix: bash, zsh
+func MarkFlagCustom(flags *pflag.FlagSet, name string, f string) error {
+	return flags.SetAnnotation(name, BashCompCustom, []string{f})
+}
+
+// MarkFlagDirname instructs the various shell completion implementations to
+// complete only directories with this named flag.
+//
+// Shell Completion compatibility matrix: zsh
+func (c *Command) MarkFlagDirname(name string) error {
+	return MarkFlagDirname(c.Flags(), name)
+}
+
+// MarkPersistentFlagDirname instructs the various shell completion
+// implementations to complete only directories with this persistent named flag.
+//
+// Shell Completion compatibility matrix: zsh
+func (c *Command) MarkPersistentFlagDirname(name string) error {
+	return MarkFlagDirname(c.PersistentFlags(), name)
+}
+
+// MarkFlagDirname instructs the various shell completion implementations to
+// complete only directories with this specified flag.
+//
+// Shell Completion compatibility matrix: zsh
+func MarkFlagDirname(flags *pflag.FlagSet, name string) error {
+	zshPattern := "-(/)"
+	return flags.SetAnnotation(name, zshCompDirname, []string{zshPattern})
+}

zsh_completions.go

@@ -16,6 +16,7 @@ const (
 	zshCompArgumentAnnotation   = "cobra_annotations_zsh_completion_argument_annotation"
 	zshCompArgumentFilenameComp = "cobra_annotations_zsh_completion_argument_file_completion"
 	zshCompArgumentWordComp     = "cobra_annotations_zsh_completion_argument_word_completion"
+	zshCompDirname              = "cobra_annotations_zsh_dirname"
 )
 
 var (
@@ -305,16 +306,21 @@ func zshCompGenFlagEntryForMultiOptionFlag(f *pflag.Flag) string {
 }
 
 func zshCompGenFlagEntryExtras(f *pflag.Flag) string {
-	var extras string
+	if f.NoOptDefVal != "" {
+		return ""
+	}
 
-	globs, pathSpecified := f.Annotations[BashCompFilenameExt]
-	if pathSpecified {
-		extras = ":filename:_files"
-		for _, g := range globs {
-			extras = extras + fmt.Sprintf(` -g "%s"`, g)
+	extras := ":" // allow options for flag (even without assistance)
+	for key, values := range f.Annotations {
+		switch key {
+		case zshCompDirname:
+			extras = fmt.Sprintf(":filename:_files -g %q", values[0])
+		case BashCompFilenameExt:
+			extras = ":filename:_files"
+			for _, pattern := range values {
+				extras = extras + fmt.Sprintf(` -g "%s"`, pattern)
+			}
 		}
-	} else if f.NoOptDefVal == "" {
-		extras = ":" // allow option variable without assisting
 	}
 
 	return extras

zsh_completions_test.go

@@ -214,6 +214,21 @@ func TestGenZshCompletion(t *testing.T) {
 				`'1: :\("word1" "word2"\)' \\`,
 			},
 		},
+		{
+			name: "directory completion for flag",
+			root: func() *Command {
+				r := genTestCommand("root", true)
+				r.Flags().String("test", "", "test")
+				r.PersistentFlags().String("ptest", "", "ptest")
+				r.MarkFlagDirname("test")
+				r.MarkPersistentFlagDirname("ptest")
+				return r
+			}(),
+			expectedExpressions: []string{
+				`--test\[test]:filename:_files -g "-\(/\)"`,
+				`--ptest\[ptest]:filename:_files -g "-\(/\)"`,
+			},
+		},
 	}
 
 	for _, tc := range tcs {