feat: Add includeTemplate template function

assets/chezmoi.io/docs/reference/templates/functions/includeTemplate.md

@@ -0,0 +1,5 @@
+# `includeTemplate` *filename* [*data*]
+
+`includeTemplate` returns the result of executing the contents of *filename*
+with the optional *data*. Relative paths are interpreted relative to the source
+directory.

assets/chezmoi.io/mkdocs.yml

@@ -176,6 +176,7 @@ nav:
       - fromYaml: reference/templates/functions/fromYaml.md
       - glob: reference/templates/functions/glob.md
       - include: reference/templates/functions/include.md
+      - includeTemplate: reference/templates/functions/includeTemplate.md
       - ioreg: reference/templates/functions/ioreg.md
       - joinPath: reference/templates/functions/joinPath.md
       - lookPath: reference/templates/functions/lookPath.md

pkg/cmd/config.go

@@ -435,6 +435,7 @@ func newConfig(options ...configOption) (*Config, error) {
 		"gopass":                   c.gopassTemplateFunc,
 		"gopassRaw":                c.gopassRawTemplateFunc,
 		"include":                  c.includeTemplateFunc,
+		"includeTemplate":          c.includeTemplateTemplateFunc,
 		"ioreg":                    c.ioregTemplateFunc,
 		"joinPath":                 c.joinPathTemplateFunc,
 		"keepassxc":                c.keepassxcTemplateFunc,

pkg/cmd/templatefuncs.go

@@ -12,6 +12,7 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+	"text/template"
 
 	"github.com/bmatcuk/doublestar/v4"
 	"github.com/bradenhilton/mozillainstallhash"
@@ -87,23 +88,41 @@ func (c *Config) globTemplateFunc(pattern string) []string {
 }
 
 func (c *Config) includeTemplateFunc(filename string) string {
-	var absPath chezmoi.AbsPath
-	if filepath.IsAbs(filename) {
-		var err error
-		absPath, err = chezmoi.NewAbsPathFromExtPath(filename, c.homeDirAbsPath)
-		if err != nil {
-			panic(err)
-		}
-	} else {
-		absPath = c.SourceDirAbsPath.JoinString(filename)
-	}
-	contents, err := c.fileSystem.ReadFile(absPath.String())
+	contents, err := c.readFile(filename)
 	if err != nil {
 		panic(err)
 	}
 	return string(contents)
 }
 
+func (c *Config) includeTemplateTemplateFunc(filename string, args ...any) string {
+	var data any
+	switch len(args) {
+	case 0:
+		// Do nothing.
+	case 1:
+		data = args[0]
+	default:
+		panic(fmt.Errorf("expected 0 or 1 arguments, got %d", len(args)))
+	}
+
+	contents, err := c.readFile(filename)
+	if err != nil {
+		panic(err)
+	}
+
+	tmpl, err := template.New(filename).Funcs(c.templateFuncs).Parse(string(contents))
+	if err != nil {
+		panic(err)
+	}
+
+	var builder strings.Builder
+	if err := tmpl.Execute(&builder, data); err != nil {
+		panic(err)
+	}
+	return builder.String()
+}
+
 func (c *Config) ioregTemplateFunc() map[string]any {
 	if runtime.GOOS != "darwin" {
 		return nil
@@ -188,6 +207,20 @@ func (c *Config) quoteListTemplateFunc(list []any) []string {
 	return result
 }
 
+func (c *Config) readFile(filename string) ([]byte, error) {
+	var absPath chezmoi.AbsPath
+	if filepath.IsAbs(filename) {
+		var err error
+		absPath, err = chezmoi.NewAbsPathFromExtPath(filename, c.homeDirAbsPath)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		absPath = c.SourceDirAbsPath.JoinString(filename)
+	}
+	return c.fileSystem.ReadFile(absPath.String())
+}
+
 func (c *Config) replaceAllRegexTemplateFunc(expr, repl, s string) string {
 	return regexp.MustCompile(expr).ReplaceAllString(s, repl)
 }

pkg/cmd/testdata/scripts/templatefuncs.txtar

@@ -24,6 +24,10 @@ cmp stdout golden/include-abspath
 exec chezmoi execute-template '{{ include ".include" }}'
 cmp stdout golden/include-relpath
 
+# test includeTemplate template function
+exec chezmoi execute-template '{{ includeTemplate ".template" "data" }}'
+stdout ^data$
+
 # test joinPath template function
 exec chezmoi execute-template '{{ joinPath "a" "b" }}'
 stdout a${/}b
@@ -158,5 +162,7 @@ subkey = "subvalue"
 # contents of .include
 -- home/user/.local/share/chezmoi/.include --
 # contents of .local/share/chezmoi/.include
+-- home/user/.local/share/chezmoi/.template --
+{{ . }}
 -- home/user/file1.txt --
 -- home/user/file2.txt --