Add jen list templates

Signed-off-by: Mathieu Frenette <[email protected]>

README.md

@@ -436,7 +436,6 @@ To associate a template with an existing project that was not initially generate
 
 - Add `confirm` step (similar to `if`, but `confirm` property contains message to display and `then` the steps to execute).
 - Add `jen export` command to output env variables in a format that can be sourced directly.
-- Add `jen list templates` to list available templates.
 - Add `jen list vars` to list project variables and their values (same as `jen export` but more human-readable).
 - Add `jen chk vars VAR1 VAR2 ...` to ensure that all given variables are set in environment (to document and make scripts more robust).
 - Allow `do` step to define multiple actions to call.

src/cmd/list/list.go

@@ -6,6 +6,7 @@ import (
 	"github.com/Samasource/jen/src/cmd/internal"
 	"github.com/Samasource/jen/src/cmd/list/actions"
 	"github.com/Samasource/jen/src/cmd/list/scripts"
+	"github.com/Samasource/jen/src/cmd/list/templates"
 	"github.com/Samasource/jen/src/internal/shell"
 	"github.com/spf13/cobra"
 )
@@ -22,6 +23,7 @@ func New(options *internal.Options) *cobra.Command {
 	}
 	c.AddCommand(actions.New(options))
 	c.AddCommand(scripts.New(options))
+	c.AddCommand(templates.New(options))
 	return c
 }
 

src/cmd/list/templates/templates.go

@@ -0,0 +1,59 @@
+package templates
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+
+	"github.com/Samasource/jen/src/cmd/internal"
+	"github.com/Samasource/jen/src/internal/home"
+	"github.com/Samasource/jen/src/internal/spec"
+	"github.com/spf13/cobra"
+)
+
+// New creates a cobra command
+func New(options *internal.Options) *cobra.Command {
+	return &cobra.Command{
+		Use:     "templates",
+		Aliases: []string{"template"},
+		Short:   "Lists templates available in git clone",
+		Args:    cobra.NoArgs,
+		RunE: func(_ *cobra.Command, args []string) error {
+			return run(options, args)
+		},
+	}
+}
+
+func run(options *internal.Options, args []string) error {
+	_, err := home.GetOrCloneRepo()
+	if err != nil {
+		return err
+	}
+
+	templatesDir, err := home.GetTemplatesDir()
+	if err != nil {
+		return err
+	}
+
+	// Read templates dir
+	infos, err := ioutil.ReadDir(templatesDir)
+	if err != nil {
+		return fmt.Errorf("reading templates directory %q: %w", templatesDir, err)
+	}
+
+	// Print templates with descriptions
+	for _, info := range infos {
+		template := info.Name()
+		if strings.HasPrefix(template, ".") {
+			continue
+		}
+		templateDir := filepath.Join(templatesDir, template)
+		spec, err := spec.Load(templateDir)
+		if err != nil {
+			return err
+		}
+		fmt.Printf("%s - %s\n", template, spec.Description)
+	}
+	return nil
+}