|
1
|
// Package envy provides type-safe environment variable access. |
|
2
|
// |
|
3
|
// It supports automatic conversion from string environment variables to common Go types: |
|
4
|
// string, int, int64, float64, bool, and time.Duration. |
|
5
|
// |
|
6
|
// If an environment variable is not set or cannot be parsed, functions return the zero value |
|
7
|
// of the requested type. |
|
8
|
package envy |
|
9
|
|
|
10
|
import ( |
|
11
|
"os" |
|
12
|
"strconv" |
|
13
|
"time" |
|
14
|
) |
|
15
|
|
|
16
|
// Get retrieves an environment variable and converts it to the specified type T. |
|
17
|
// Supported types: string, int, int64, float64, bool, time.Duration. |
|
18
|
// |
|
19
|
// If the environment variable is not set or cannot be parsed, returns the zero value of T. |
|
20
|
func Get[T comparable](key string) T { |
|
21
|
var zero T |
|
22
|
val, ok := os.LookupEnv(key) |
|
23
|
if !ok { |
|
24
|
return zero |
|
25
|
} |
|
26
|
|
|
27
|
var res any |
|
28
|
switch any(zero).(type) { |
|
29
|
case string: |
|
30
|
res = val |
|
31
|
case int: |
|
32
|
if n, err := strconv.Atoi(val); err == nil { |
|
33
|
res = n |
|
34
|
} |
|
35
|
case int64: |
|
36
|
if n, err := strconv.ParseInt(val, 10, 64); err == nil { |
|
37
|
res = n |
|
38
|
} |
|
39
|
case float64: |
|
40
|
if f, err := strconv.ParseFloat(val, 64); err == nil { |
|
41
|
res = f |
|
42
|
} |
|
43
|
case bool: |
|
44
|
if b, err := strconv.ParseBool(val); err == nil { |
|
45
|
res = b |
|
46
|
} |
|
47
|
case time.Duration: |
|
48
|
if d, err := time.ParseDuration(val); err == nil { |
|
49
|
res = d |
|
50
|
} |
|
51
|
} |
|
52
|
return res.(T) |
|
53
|
} |
|
54
|
|
|
55
|
// GetOrDefault retrieves an environment variable, if not set, returns default value. |
|
56
|
// Supported types: string, int, int64, float64, bool, time.Duration. |
|
57
|
func GetOrDefault[T comparable](key string, def T) T { |
|
58
|
var zero T |
|
59
|
if val := Get[T](key); val != zero { |
|
60
|
return val |
|
61
|
} |
|
62
|
return def |
|
63
|
} |