feat: support filesystem features

engine.go

@@ -2,6 +2,7 @@ package easytemplate
 
 import (
  "fmt"
+ "io/fs"
  "os"
  "path"
  "text/template"
@@ -10,17 +11,25 @@ import (
  _ "github.com/robertkrimen/otto/underscore"
 )
 
+type WriteFunc func(string, []byte) error
+
 type Opt func(*Engine)
 
-func WithTemplateDir(templateDir string) Opt {
+func WithBaseDir(baseDir string) Opt {
+ return func(e *Engine) {
+ e.baseDir = baseDir
+ }
+}
+
+func WithReadFileSystem(fs fs.FS) Opt {
  return func(e *Engine) {
- e.templateDir = templateDir
+ e.readFS = fs
  }
 }
 
-func WithScriptDir(scriptDir string) Opt {
+func WithWriteFunc(writeFunc WriteFunc) Opt {
  return func(e *Engine) {
- e.scriptDir = scriptDir
+ e.writeFunc = writeFunc
  }
 }
 
@@ -49,8 +58,9 @@ func WithJSFuncs(funcs map[string]func(call otto.FunctionCall) otto.Value) Opt {
 }
 
 type Engine struct {
- templateDir string
- scriptDir string
+ baseDir string
+ readFS fs.FS
+ writeFunc WriteFunc
  ran bool
  tmplFuncs template.FuncMap
  jsFuncs map[string]func(call otto.FunctionCall) otto.Value
@@ -88,7 +98,12 @@ func (e *Engine) RunScript(scriptFile string, data any) error {
  return err
  }
 
- s, err := vm.Compile(scriptFile, nil)
+ script, err := e.ReadFile(scriptFile)
+ if err != nil {
+ return fmt.Errorf("failed to read script file: %w", err)
+ }
+
+ s, err := vm.Compile("", script)
  if err != nil {
  return fmt.Errorf("failed to compile script: %w", err)
  }
@@ -106,16 +121,16 @@ func (e *Engine) RunTemplate(templateFile string, outFile string, data any) erro
  return err
  }
 
- templated, err := e.tmpl(vm, templateFile, data)
- if err != nil {
- return fmt.Errorf("failed to template file: %w", err)
- }
+ return e.templateFile(vm, templateFile, outFile, data)
+}
 
- if err := os.WriteFile(outFile, []byte(templated), 0o644); err != nil {
- return fmt.Errorf("failed to write file: %w", err)
+func (e *Engine) RunTemplateString(templateString string, data any) (string, error) {
+ vm, err := e.init(data)
+ if err != nil {
+ return "", err
  }
 
- return nil
+ return e.tmpl(vm, templateString, data)
 }
 
 func (e *Engine) init(data any) (*otto.Otto, error) {
@@ -170,11 +185,12 @@ func (e *Engine) require(call otto.FunctionCall) otto.Value {
 
  scriptPath := call.Argument(0).String()
 
- if e.scriptDir != "" {
- scriptPath = path.Join(e.scriptDir, scriptPath)
+ script, err := e.ReadFile(scriptPath)
+ if err != nil {
+ panic(vm.MakeCustomError("requireScript", err.Error()))
  }
 
- s, err := vm.Compile(scriptPath, nil)
+ s, err := vm.Compile("", script)
  if err != nil {
  panic(vm.MakeCustomError("requireScript", err.Error()))
  }
@@ -212,3 +228,16 @@ func (e *Engine) registerTemplateFunc(call otto.FunctionCall) otto.Value {
 
  return otto.Value{}
 }
+
+func (e *Engine) ReadFile(file string) ([]byte, error) {
+ filePath := file
+ if e.baseDir != "" {
+ filePath = path.Join(e.baseDir, filePath)
+ }
+
+ if e.readFS != nil {
+ return fs.ReadFile(e.readFS, filePath)
+ } else {
+ return os.ReadFile(filePath)
+ }
+}

templating.go

@@ -4,7 +4,6 @@ import (
  "bytes"
  "fmt"
  "os"
- "path"
  "regexp"
  "strings"
  "text/template"
@@ -38,8 +37,14 @@ func (e *Engine) templateFile(vm *otto.Otto, templateFile, outFile string, input
  return err
  }
 
- if err := os.WriteFile(outFile, []byte(output), 0o644); err != nil {
- return err
+ if e.writeFunc != nil {
+ err = e.writeFunc(outFile, []byte(output))
+ } else {
+ err = os.WriteFile(outFile, []byte(output), 0o644)
+ }
+
+ if err != nil {
+ return fmt.Errorf("failed to write file %s: %w", outFile, err)
  }
 
  return nil
@@ -101,12 +106,7 @@ func (e *Engine) tmpl(vm *otto.Otto, templatePath string, inputData any) (out st
  return "", fmt.Errorf("failed to set context: %w", err)
  }
 
- tp := templatePath
- if e.templateDir != "" {
- tp = path.Join(e.templateDir, templatePath)
- }
-
- data, err := os.ReadFile(tp)
+ data, err := e.ReadFile(templatePath)
  if err != nil {
  return "", fmt.Errorf("failed to read template file: %w", err)
  }