1package interpolate
 2
 3import (
 4	"runtime"
 5	"strings"
 6)
 7
 8// Env is an interface for getting environment variables by name and returning a boolean indicating
 9// whether the variable was found.
10type Env interface {
11	Get(key string) (string, bool)
12}
13
14// NewSliceEnv creates an Env from a slice of environment variables in the form "key=value".
15//
16// This can be used with [os.Environ] to create an Env.
17func NewSliceEnv(env []string) Env {
18	envMap := mapEnv{}
19	for _, l := range env {
20		parts := strings.SplitN(l, "=", 2)
21		if len(parts) == 2 {
22			envMap[normalizeKeyName(parts[0])] = parts[1]
23		}
24	}
25	return envMap
26}
27
28// NewMapEnv creates an Env from a map of environment variables.
29func NewMapEnv(env map[string]string) Env {
30	envMap := mapEnv{}
31	for k, v := range env {
32		envMap[normalizeKeyName(k)] = v
33	}
34	return envMap
35}
36
37type mapEnv map[string]string
38
39func (m mapEnv) Get(key string) (string, bool) {
40	if m == nil {
41		return "", false
42	}
43	val, ok := m[normalizeKeyName(key)]
44	return val, ok
45}
46
47// Windows isn't case sensitive for env
48func normalizeKeyName(key string) string {
49	if runtime.GOOS == "windows" {
50		return strings.ToUpper(key)
51	}
52	return key
53}