fix #2 bad field name is logged in resulting panic (#3)

Author: bjubes

configurator.go

@@ -1,7 +1,6 @@
 package config
 
 import (
-	"fmt"
 	"log"
 	"os"
 	"reflect"
@@ -24,7 +23,7 @@ type Configurator interface {
 func GetEnvString(config Configurator, field string) string {
 	defer func() {
 		if r := recover(); r != nil {
-			log.Fatalln(r)
+			log.Panicf("configurator has no field named '%s'", field)
 		}
 	}()
 	value, exists := os.LookupEnv(field)
@@ -39,7 +38,7 @@ func GetEnvString(config Configurator, field string) string {
 func GetEnvBool(config Configurator, field string) bool {
 	defer func() {
 		if r := recover(); r != nil {
-			log.Fatalln(r)
+			log.Panicf("configurator has no field named '%s'", field)
 		}
 	}()
 	value, err := strconv.ParseBool(os.Getenv(field))
@@ -54,7 +53,7 @@ func GetEnvBool(config Configurator, field string) bool {
 func GetEnvInt(config Configurator, field string) int {
 	defer func() {
 		if r := recover(); r != nil {
-			log.Fatalln(r)
+			log.Panicf("configurator has no field named '%s'", field)
 		}
 	}()
 	value, err := strconv.Atoi(os.Getenv(field))
@@ -69,7 +68,7 @@ func GetEnvInt(config Configurator, field string) int {
 func GetEnvFloat(config Configurator, field string) float64 {
 	defer func() {
 		if r := recover(); r != nil {
-			log.Fatalln(r)
+			log.Panicf("configurator has no field named '%s'", field)
 		}
 	}()
 	value, err := strconv.ParseFloat(os.Getenv(field), 64)
@@ -89,7 +88,7 @@ func getString(c any, field string) string {
 	result := field_value.String()
 	re := regexp.MustCompile(`<[a-zA-Z]*\sValue>`)
 	if re.MatchString(result) {
-		panic(fmt.Sprintf("env var not in config struct: `%v`", field))
+		log.Panicf("configurator has no field named '%s'", field)
 	}
 	return result
 }
@@ -116,7 +115,7 @@ func getNonString(c any, field string) reflect.Value {
 	defer func() {
 		//catch panic when field does not exist
 		if r := recover(); r != nil {
-			panic(fmt.Sprintf("env var not in config struct: `%v`", field))
+			log.Panicf("configurator has no field named '%s'", field)
 		}
 	}()
 	c_value := reflect.ValueOf(c)

configurator_test.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"os"
+	"strings"
 	"testing"
 )
 
@@ -213,6 +214,36 @@ func TestBoolWithBadEnvStrings(t *testing.T) {
 	}
 }
 
+func TestPanicMessageIncludesFieldName(t *testing.T) {
+	panicCheck := func(f func()) {
+		field_name := "DOES_NOT_EXIST"
+		defer func() {
+			r := recover()
+			if r == nil {
+				t.Errorf("Reading non existant field did not cause panic")
+			} else {
+				switch v := r.(type) {
+				case string:
+					if !strings.Contains(v, field_name) {
+						t.Errorf("Panic msg should contain field name '%s'. Got '%v'", field_name, r)
+					}
+				case error:
+					if !strings.Contains(v.Error(), "DOES_NOT_EXIST") {
+						t.Errorf("Panic msg should contain field name '%s'. Got '%v'", field_name, r)
+					}
+				default:
+					t.Errorf("Panic's type is unkown. Cannot check error msg. Type is '%T'", r)
+				}
+			}
+		}()
+		f()
+	}
+	panicCheck(func() { config_iface.GetEnvInt("DOES_NOT_EXIST") })
+	panicCheck(func() { config_iface.GetEnvFloat("DOES_NOT_EXIST") })
+	panicCheck(func() { config_iface.GetEnvString("DOES_NOT_EXIST") })
+	panicCheck(func() { config_iface.GetEnvBool("DOES_NOT_EXIST") })
+}
+
 func use(vals ...any) {
 	for _, val := range vals {
 		_ = val