switch how to hook different lookup to simple function instead of int…

…erface, also fix bug found when using the mock in test (recurse was using the os version)

env.go

@@ -254,7 +254,7 @@ func setPointer(fieldValue reflect.Value) reflect.Value {
 }
 
 func checkEnv(envLookup EnvLookup, envName, fieldName string, fieldValue reflect.Value) (*string, error) {
-	val, found := envLookup.LookupEnv(envName)
+	val, found := envLookup(envName)
 	if !found {
 		// log.LogVf("%q not set for %s", envName, fieldName)
 		return nil, nil //nolint:nilnil
@@ -267,22 +267,11 @@ func checkEnv(envLookup EnvLookup, envName, fieldName string, fieldValue reflect
 	return &val, nil
 }
 
-// EnvLookup defines the interface for looking up environment variables.
-type EnvLookup interface {
-	LookupEnv(key string) (string, bool)
-}
-
-// DefaultEnvLookup implements the EnvLookup interface using the os package.
-type DefaultEnvLookup struct{}
-
-// LookupEnv for DefaultEnvLookup uses the os.LookupEnv function.
-func (DefaultEnvLookup) LookupEnv(key string) (string, bool) {
-	return os.LookupEnv(key)
-}
+type EnvLookup func(key string) (string, bool)
 
 // Reverse of StructToEnvVars, assumes the same encoding. Using the current os environment variables as source.
 func SetFromEnv(prefix string, s interface{}) []error {
-	return SetFrom(DefaultEnvLookup{}, prefix, s)
+	return SetFrom(os.LookupEnv, prefix, s)
 }
 
 // Reverse of StructToEnvVars, assumes the same encoding. Using passed it lookup object that can lookup values by keys.
@@ -321,7 +310,7 @@ func setFromEnv(allErrors []error, envLookup EnvLookup, prefix string, s interfa
 		if kind == reflect.Struct {
 			// Recurse with prefix
 			if fieldValue.CanAddr() { // Check if we can get the address
-				SetFromEnv(envName+"_", fieldValue.Addr().Interface())
+				allErrors = setFromEnv(allErrors, envLookup, envName+"_", fieldValue.Addr().Interface())
 			} else {
 				err := fmt.Errorf("cannot take the address of %s to recurse", fieldType.Name)
 				allErrors = append(allErrors, err)

env_test.go

@@ -1,7 +1,6 @@
 package struct2env
 
 import (
-	"os"
 	"reflect"
 	"strings"
 	"testing"
@@ -200,31 +199,33 @@ export TST_FOO TST_BAR TST_A_SPECIAL_BLAH TST_A_BOOL TST_HTTP_SERVER TST_INT_POI
 
 func TestSetFromEnv(t *testing.T) {
 	foo := FooConfig{}
-	envs := []struct {
-		k string
-		v string
-	}{
-		{"TST2_FOO", "another\nfoo"},
-		{"TST2_BAR", "bar"},
-		{"TST2_RECURSE_HERE_INNER_B", "in1"},
-		{"TST2_A_SPECIAL_BLAH", "31"},
-		{"TST2_A_BOOL", "1"},
-		{"TST2_FLOAT_POINTER", "5.75"},
-		{"TST2_INT_POINTER", "73"},
-		{"TST2_SOME_BINARY", "QUJDAERFRg=="},
-	}
-	for _, e := range envs {
-		os.Setenv(e.k, e.v)
-	}
-	errors := SetFromEnv("TST2_", &foo)
+	envs := map[string]string{
+		"TST2_FOO":                  "another\nfoo",
+		"TST2_BAR":                  "bar",
+		"TST2_RECURSE_HERE_INNER_B": "in1",
+		"TST2_A_SPECIAL_BLAH":       "31",
+		"TST2_A_BOOL":               "1",
+		"TST2_FLOAT_POINTER":        "5.75",
+		"TST2_INT_POINTER":          "73",
+		"TST2_SOME_BINARY":          "QUJDAERFRg==",
+	}
+	lookup := func(key string) (string, bool) {
+		value, found := envs[key]
+		return value, found
+	}
+	errors := SetFrom(lookup, "TST2_", &foo)
 	if len(errors) != 0 {
 		t.Errorf("Unexpectedly got errors :%v", errors)
 	}
-	if foo.Foo != "another\nfoo" || foo.Bar != "bar" || foo.RecurseHere.InnerB != "in1" || foo.Blah != 31 || foo.ABool != true ||
-		foo.FloatPointer == nil || *foo.FloatPointer != 5.75 ||
-		foo.IntPointer == nil || *foo.IntPointer != 73 {
+	if foo.Foo != "another\nfoo" || foo.Bar != "bar" || foo.RecurseHere.InnerB != "in1" || foo.Blah != 31 || foo.ABool != true {
 		t.Errorf("Mismatch in object values, got: %+v", foo)
 	}
+	if foo.IntPointer == nil || *foo.IntPointer != 73 {
+		t.Errorf("IntPointer not set correctly: %v %v", foo.IntPointer, *foo.IntPointer)
+	}
+	if foo.FloatPointer == nil || *foo.FloatPointer != 5.75 {
+		t.Errorf("FloatPointer not set correctly: %v %v", foo.FloatPointer, *foo.FloatPointer)
+	}
 	if string(foo.SomeBinary) != "ABC\x00DEF" {
 		t.Errorf("Base64 decoding not working for []byte field: %q", string(foo.SomeBinary))
 	}