From 9fcb2835b6a8a5ee6bf66ad9bb04c9f65901a20b Mon Sep 17 00:00:00 2001
From: Oleg Balunenko <oleg.balunenko@gmail.com>
Date: Wed, 26 Jul 2023 15:12:45 +0400
Subject: [PATCH] refactor: Use generic parser for float (#106)

---
 internal/iface.go        |  4 +--
 internal/parsers.go      | 75 ++++++++++++++++++----------------------
 internal/parsers_test.go |  4 +--
 3 files changed, 37 insertions(+), 46 deletions(-)

diff --git a/internal/iface.go b/internal/iface.go
index 7287fb0e..a1139ce0 100644
--- a/internal/iface.go
+++ b/internal/iface.go
@@ -335,7 +335,7 @@ func (i int64SliceParser) ParseEnv(key string, defaltVal any, options Parameters
 type float32Parser float32
 
 func (f float32Parser) ParseEnv(key string, defaltVal any, _ Parameters) any {
-	val := float32OrDefault(key, defaltVal.(float32))
+	val := floatOrDefaultGen(key, defaltVal.(float32))
 
 	return val
 }
@@ -343,7 +343,7 @@ func (f float32Parser) ParseEnv(key string, defaltVal any, _ Parameters) any {
 type float64Parser float64
 
 func (f float64Parser) ParseEnv(key string, defaltVal any, _ Parameters) any {
-	val := float64OrDefault(key, defaltVal.(float64))
+	val := floatOrDefaultGen(key, defaltVal.(float64))
 
 	return val
 }
diff --git a/internal/parsers.go b/internal/parsers.go
index c0b74a4f..eed4566d 100644
--- a/internal/parsers.go
+++ b/internal/parsers.go
@@ -229,6 +229,39 @@ func int8SliceOrDefault(key string, defaultVal []int8, sep string) []int8 {
 	return val
 }
 
+func floatOrDefaultGen[T float32 | float64](key string, defaultVal T) T {
+	env := stringOrDefault(key, "")
+	if env == "" {
+		return defaultVal
+	}
+
+	const (
+		bitsize = 64
+	)
+
+	var (
+		castFn func(val float64) T
+	)
+
+	switch any(defaultVal).(type) {
+	case float32:
+		castFn = func(val float64) T {
+			return any(float32(val)).(T)
+		}
+	case float64:
+		castFn = func(val float64) T {
+			return any(val).(T)
+		}
+	}
+
+	val, err := strconv.ParseFloat(env, bitsize)
+	if err != nil {
+		return defaultVal
+	}
+
+	return castFn(val)
+}
+
 func intOrDefaultGen[T int | int8 | int16 | int32 | int64](key string, defaultVal T) T {
 	env := stringOrDefault(key, "")
 	if env == "" {
@@ -416,48 +449,6 @@ func durationSliceOrDefault(key string, defaultVal []time.Duration, separator st
 	return val
 }
 
-// float32OrDefault retrieves the float32 value of the environment variable named
-// by the key.
-// If variable not set or value is empty - defaultVal will be returned.
-func float32OrDefault(key string, defaultVal float32) float32 {
-	env := stringOrDefault(key, "")
-	if env == "" {
-		return defaultVal
-	}
-
-	const (
-		bitsize = 32
-	)
-
-	val, err := strconv.ParseFloat(env, bitsize)
-	if err != nil {
-		return defaultVal
-	}
-
-	return float32(val)
-}
-
-// float64OrDefault retrieves the float64 value of the environment variable named
-// by the key.
-// If variable not set or value is empty - defaultVal will be returned.
-func float64OrDefault(key string, defaultVal float64) float64 {
-	env := stringOrDefault(key, "")
-	if env == "" {
-		return defaultVal
-	}
-
-	const (
-		bitsize = 64
-	)
-
-	val, err := strconv.ParseFloat(env, bitsize)
-	if err != nil {
-		return defaultVal
-	}
-
-	return val
-}
-
 // uint64OrDefault retrieves the unt64 value of the environment variable named
 // by the key.
 // If variable not set or value is empty - defaultVal will be returned.
diff --git a/internal/parsers_test.go b/internal/parsers_test.go
index 1a528470..867f432a 100644
--- a/internal/parsers_test.go
+++ b/internal/parsers_test.go
@@ -537,7 +537,7 @@ func Test_float32OrDefault(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			tt.precond.maybeSetEnv(t, tt.args.key)
 
-			got := float32OrDefault(tt.args.key, tt.args.defaultVal)
+			got := floatOrDefaultGen(tt.args.key, tt.args.defaultVal)
 			assert.Equal(t, tt.expected.val, got)
 		})
 	}
@@ -613,7 +613,7 @@ func Test_float64OrDefault(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			tt.precond.maybeSetEnv(t, tt.args.key)
 
-			got := float64OrDefault(tt.args.key, tt.args.defaultVal)
+			got := floatOrDefaultGen(tt.args.key, tt.args.defaultVal)
 			assert.Equal(t, tt.expected.val, got)
 		})
 	}