chore: remove config responsibility

internal/config/config.go

@@ -2,17 +2,12 @@ package config
 
 import (
 	"flag"
-	"io"
-	"os"
-
-	"github.com/charmbracelet/log"
-
-	intio "github.com/ivanvc/tpl/internal/io"
 )
 
 // Config represents the configuration options for the program.
 type Config struct {
 	Input            string
+	InputFile        string
 	Env              string
 	UseStdin         bool
 	SetDebugLogLevel bool
@@ -27,21 +22,7 @@ func Load() *Config {
 	flag.BoolVar(&c.SetDebugLogLevel, "debug", false, "Set debug log level")
 	flag.Parse()
 
-	if len(c.Input) == 0 {
-		c.Input = string(intio.ReadFile(flag.Arg(0)))
-	}
-	if c.UseStdin {
-		b, err := io.ReadAll(os.Stdin)
-		if err != nil {
-			log.Fatal("Could not read input template")
-		}
-		c.Input = string(b)
-	}
-
-	if c.SetDebugLogLevel {
-		log.Default().SetLevel(log.DebugLevel)
-	}
+	c.InputFile = flag.Arg(0)
 
-	log.Debug("Loaded configuration", "config", c)
 	return c
 }

internal/io/io.go

@@ -3,18 +3,16 @@ package io
 import (
 	"io"
 	"os"
-
-	"github.com/charmbracelet/log"
 )
 
-func ReadFile(file string) []byte {
+func ReadFile(file string) ([]byte, error) {
 	f, err := os.Open(file)
 	if err != nil {
-		log.Fatal("Error opening file", "file", file, "error", err)
+		return nil, err
 	}
 	b, err := io.ReadAll(f)
 	if err != nil {
-		log.Fatal("Error reading file", "file", file, "error", err)
+		return nil, err
 	}
-	return b
+	return b, nil
 }

internal/template/environment.go

@@ -19,10 +19,13 @@ func loadEnvironment(cfg *config.Config) environment {
 	input := []byte(cfg.Env)
 
 	if cfg.Env[0] == '@' {
-		if _, err := os.Stat(cfg.Env[1:]); err == nil {
-			input = io.ReadFile(cfg.Env[1:])
+		f := cfg.Env[1:]
+		if _, err := os.Stat(f); err == nil {
+			if input, err = io.ReadFile(f); err != nil {
+				log.Warn("Error reading file", "error", err, "file", f)
+			}
 		} else {
-			log.Debug("Error opening file", "error", err, "file", cfg.Env[1:])
+			log.Debug("Error opening file", "error", err, "file", f)
 		}
 	}
 

internal/template/template.go

@@ -2,23 +2,54 @@ package template
 
 import (
 	"html/template"
+	"io"
 	"os"
 
 	"github.com/Masterminds/sprig/v3"
 	"github.com/charmbracelet/log"
 
 	"github.com/ivanvc/tpl/internal/config"
+	intio "github.com/ivanvc/tpl/internal/io"
 	tpl "github.com/ivanvc/tpl/pkg/template"
 )
 
 // Runs the template to generate the output.
 func Run(cfg *config.Config) {
+	input, err := loadInput(cfg)
+	if err != nil {
+		log.Fatal("Error loading input template", "error", err)
+	}
+	if len(input) == 0 {
+		log.Warn("Empty input template")
+	}
+	log.Debug("Loaded input template", "tpl", input)
+
 	env := loadEnvironment(cfg)
 	log.Debug("Loaded environment", "env", env)
-	input := cfg.Input
+
 	t := template.New("input")
 	tpl := template.Must(t.Funcs(sprig.TxtFuncMap()).Funcs(tpl.IncludeFunc(t)).Parse(input))
 	if err := tpl.Execute(os.Stdout, env); err != nil {
 		log.Fatal("Error executing template", "error", err)
 	}
 }
+
+func loadInput(cfg *config.Config) (string, error) {
+	var input string
+	if len(cfg.InputFile) > 0 {
+		b, err := intio.ReadFile(cfg.InputFile)
+		if err != nil {
+			return input, err
+		}
+		input = string(b)
+	} else if cfg.UseStdin {
+		b, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			return input, err
+		}
+		input = string(b)
+	} else {
+		input = cfg.Input
+	}
+	return input, nil
+}

main.go

@@ -1,11 +1,17 @@
 package main
 
 import (
+	"github.com/charmbracelet/log"
 	"github.com/ivanvc/tpl/internal/config"
 	"github.com/ivanvc/tpl/internal/template"
 )
 
 func main() {
 	cfg := config.Load()
+	if cfg.SetDebugLogLevel {
+		log.Default().SetLevel(log.DebugLevel)
+	}
+	log.Debug("Loaded configuration", "config", cfg)
+
 	template.Run(cfg)
 }