From befaf9a086c5e7db885e1ca3d36aa4e8b9d3a57d Mon Sep 17 00:00:00 2001
From: Seth Vargo <seth@sethvargo.com>
Date: Tue, 31 May 2022 09:43:59 -0400
Subject: [PATCH] Cleanup docs and add another test after #57

---
 envconfig.go      | 15 ++++++++-------
 envconfig_test.go | 30 ++++++++++++++++++++++++++++--
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/envconfig.go b/envconfig.go
index c8ee7f8..26ef06c 100644
--- a/envconfig.go
+++ b/envconfig.go
@@ -241,7 +241,9 @@ func ProcessWith(ctx context.Context, i interface{}, l Lookuper, fns ...MutatorF
 	return processWith(ctx, i, l, false, fns...)
 }
 
-func processWith(ctx context.Context, i interface{}, l Lookuper, pnoinit bool, fns ...MutatorFunc) error {
+// processWith is a helper that captures whether the parent wanted
+// initialization.
+func processWith(ctx context.Context, i interface{}, l Lookuper, parentNoInit bool, fns ...MutatorFunc) error {
 	if l == nil {
 		return ErrLookuperNil
 	}
@@ -290,12 +292,11 @@ func processWith(ctx context.Context, i interface{}, l Lookuper, pnoinit bool, f
 			origin := e.Field(i)
 			if isNilStructPtr {
 				empty := reflect.New(origin.Type().Elem()).Interface()
-				// If a struct (after traversal) equals to the empty value,
-				// it means nothing was changed in any sub-fields.
-				// With the noinit opt, we skip setting the empty value
-				// to the original struct pointer (aka. keep it nil).
-				if !reflect.DeepEqual(v.Interface(), empty) || !(opts.NoInit || pnoinit) {
-				//if !reflect.DeepEqual(v.Interface(), empty) {
+				// If a struct (after traversal) equals to the empty value, it means
+				// nothing was changed in any sub-fields. With the noinit opt, we skip
+				// setting the empty value to the original struct pointer (aka. keep it
+				// nil).
+				if !reflect.DeepEqual(v.Interface(), empty) || (!opts.NoInit && !parentNoInit) {
 					origin.Set(v)
 				}
 			}
diff --git a/envconfig_test.go b/envconfig_test.go
index fc46b3e..82404d7 100644
--- a/envconfig_test.go
+++ b/envconfig_test.go
@@ -1654,9 +1654,33 @@ func TestProcessWith(t *testing.T) {
 			}),
 		},
 
-		// No init
+		// Init (default behavior)
 		{
-			name: "noinit/init_with_nil_structs",
+			name: "init/basic",
+			input: &struct {
+				Field1 string    `env:"FIELD1"`
+				Field2 bool      `env:"FIELD2"`
+				Field3 int64     `env:"FIELD3"`
+				Field4 float64   `env:"FIELD4"`
+				Field5 complex64 `env:"FIELD5"`
+			}{},
+			exp: &struct {
+				Field1 string    `env:"FIELD1"`
+				Field2 bool      `env:"FIELD2"`
+				Field3 int64     `env:"FIELD3"`
+				Field4 float64   `env:"FIELD4"`
+				Field5 complex64 `env:"FIELD5"`
+			}{
+				Field1: "",
+				Field2: false,
+				Field3: 0,
+				Field4: 0,
+				Field5: 0,
+			},
+			lookuper: MapLookuper(map[string]string{}),
+		},
+		{
+			name: "init/structs",
 			input: &struct {
 				Electron *Electron
 			}{},
@@ -1675,6 +1699,8 @@ func TestProcessWith(t *testing.T) {
 			},
 			lookuper: MapLookuper(map[string]string{}),
 		},
+
+		// No init
 		{
 			name: "noinit/no_init_when_sub_fields_unset",
 			input: &struct {