feat(commit): text templating in commit messages

cmd/template.go

@@ -0,0 +1,85 @@
+/*
+Copyright © 2025 Lewis Wynne <lew@ily.rs>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"slices"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+)
+
+// templateFuncMap returns the shared FuncMap used by both value templates
+// (pda get) and commit message templates.
+func templateFuncMap() template.FuncMap {
+	return template.FuncMap{
+		"require": func(v any) (string, error) {
+			s := fmt.Sprint(v)
+			if s == "" {
+				return "", fmt.Errorf("required value is missing or empty")
+			}
+			return s, nil
+		},
+		"default": func(def string, v any) string {
+			s := fmt.Sprint(v)
+			if s == "" {
+				return def
+			}
+			return s
+		},
+		"env": os.Getenv,
+		"enum": func(v any, allowed ...string) (string, error) {
+			s := fmt.Sprint(v)
+			if s == "" {
+				return "", fmt.Errorf("enum value is missing or empty")
+			}
+			if slices.Contains(allowed, s) {
+				return s, nil
+			}
+			return "", fmt.Errorf("invalid value '%s', allowed: %v", s, allowed)
+		},
+		"int": func(v any) (int, error) {
+			s := fmt.Sprint(v)
+			i, err := strconv.Atoi(s)
+			if err != nil {
+				return 0, fmt.Errorf("cannot convert to int: %w", err)
+			}
+			return i, nil
+		},
+		"list": func(v any) []string {
+			s := fmt.Sprint(v)
+			if s == "" {
+				return nil
+			}
+			parts := strings.Split(s, ",")
+			for i := range parts {
+				parts[i] = strings.TrimSpace(parts[i])
+			}
+			return parts
+		},
+		"time": func() string { return time.Now().UTC().Format(time.RFC3339) },
+	}
+}