test all keyvalue and fix bugs

config/keyvalue/keyvalue.go

@@ -23,21 +23,30 @@ func (kv KVSlice) Less(i, j int) bool { return kv[i].Key < kv[j].Key }
 func (kv KVSlice) Swap(i, j int)      { kv[i], kv[j] = kv[j], kv[i] }
 
 // EnvKV turns a struct with `env` keys (used with go-simpler/env) into a standard formatted
-// environment variable key/value pair list, one per line. Note you must dereference a pointer
-// type to use this. This allows the composition of the config in this file with an extended
-// form with a customized variant of realy to produce correct environment variables both read
-// and write.
+// environment variable key/value pair list, one per line. If a pointer to a struct is passed,
+// it will be automatically dereferenced. This allows the composition of the config in this file
+// with an extended form with a customized variant of realy to produce correct environment
+// variables both read and write.
 func EnvKV(cfg any) (m KVSlice) {
-	t := reflect.TypeOf(cfg)
+	// Handle pointer types by dereferencing them
+	v := reflect.ValueOf(cfg)
+	if v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return // Return empty slice for nil pointers
+		}
+		return EnvKV(v.Elem().Interface())
+	}
+
+	t := v.Type()
 	for i := 0; i < t.NumField(); i++ {
 		k := t.Field(i).Tag.Get("env")
-		v := reflect.ValueOf(cfg).Field(i).Interface()
+		fieldValue := v.Field(i).Interface()
 		var val string
-		switch u := v.(type) {
+		switch u := fieldValue.(type) {
 		case string:
 			val = u
 		case int, int64, int32, uint64, uint32, bool, time.Duration:
-			val = fmt.Sprint(v)
+			val = fmt.Sprint(fieldValue)
 		case []string:
 			if len(u) > 0 {
 				val = strings.Join(u, ",")
@@ -52,7 +61,8 @@ func EnvKV(cfg any) (m KVSlice) {
 	return
 }
 
-// PrintEnv renders the key/values of a config.C to a provided io.Writer.
+// PrintEnv renders the key/values of a config struct to a provided io.Writer.
+// If a pointer to a struct is passed, it will be automatically dereferenced.
 func PrintEnv(cfg any, printer io.Writer) {
 	_, _ = fmt.Fprintln(printer, "#!/usr/bin/env bash")
 	kvs := EnvKV(cfg)

config/keyvalue/keyvalue_test.go

@@ -90,10 +90,58 @@ func TestEnvKV(t *testing.T) {
 	if !found {
 		t.Errorf("Expected to find ADDITIONAL_FIELD with value 'additional' in embedded struct")
 	}
+
+	// Test case 3: Pointer to a struct
+	pointerStruct := &TestStruct{
+		StringField:   "pointer-string",
+		IntField:      123,
+		BoolField:     false,
+		DurationField: 10 * time.Second,
+		StringSlice:   []string{"four", "five", "six"},
+	}
+
+	pointerKVs := EnvKV(pointerStruct)
+
+	// Expected key-value pairs for pointer struct
+	expectedPointer := KVSlice{
+		{Key: "STRING_FIELD", Value: "pointer-string"},
+		{Key: "INT_FIELD", Value: "123"},
+		{Key: "BOOL_FIELD", Value: "false"},
+		{Key: "DURATION_FIELD", Value: "10s"},
+		{Key: "STRING_SLICE", Value: "four,five,six"},
+		{Key: "EMPTY_SLICE", Value: ""},
+	}
+
+	// Check if the number of key-value pairs is correct
+	if len(pointerKVs) != len(expectedPointer) {
+		t.Errorf("Expected %d key-value pairs for pointer struct, got %d", len(expectedPointer), len(pointerKVs))
+	}
+
+	// Create a map for easier comparison
+	pointerKVMap := make(map[string]string)
+	for _, kv := range pointerKVs {
+		pointerKVMap[kv.Key] = kv.Value
+	}
+
+	// Check if all expected key-value pairs are present
+	for _, kv := range expectedPointer {
+		if val, ok := pointerKVMap[kv.Key]; !ok || val != kv.Value {
+			t.Errorf("Expected key %s with value %s for pointer struct, got %s", kv.Key, kv.Value, val)
+		}
+	}
+
+	// Test case 4: Nil pointer
+	var nilPointer *TestStruct = nil
+	nilKVs := EnvKV(nilPointer)
+
+	// Nil pointer should return empty slice
+	if len(nilKVs) != 0 {
+		t.Errorf("Expected empty slice for nil pointer, got %d items", len(nilKVs))
+	}
 }
 
 func TestPrintEnv(t *testing.T) {
-	// Create a test struct
+	// Test case 1: Regular struct
 	testStruct := TestStruct{
 		StringField:   "test-string",
 		IntField:      42,
@@ -123,6 +171,56 @@ func TestPrintEnv(t *testing.T) {
 	if output != expected {
 		t.Errorf("PrintEnv output does not match expected.\nExpected:\n%s\nGot:\n%s", expected, output)
 	}
+
+	// Test case 2: Pointer to struct
+	pointerStruct := &TestStruct{
+		StringField:   "pointer-string",
+		IntField:      123,
+		BoolField:     false,
+		DurationField: 10 * time.Second,
+		StringSlice:   []string{"four", "five", "six"},
+	}
+
+	// Create a new buffer for the pointer test
+	var pointerBuf bytes.Buffer
+
+	// Call PrintEnv with a pointer
+	PrintEnv(pointerStruct, &pointerBuf)
+
+	// Get the output as a string
+	pointerOutput := pointerBuf.String()
+
+	// Expected output for pointer struct
+	expectedPointer := "#!/usr/bin/env bash\n" +
+		"export BOOL_FIELD=false\n" +
+		"export DURATION_FIELD=10s\n" +
+		"export EMPTY_SLICE=\n" +
+		"export INT_FIELD=123\n" +
+		"export STRING_FIELD=pointer-string\n" +
+		"export STRING_SLICE=four,five,six\n"
+
+	if pointerOutput != expectedPointer {
+		t.Errorf("PrintEnv output for pointer struct does not match expected.\nExpected:\n%s\nGot:\n%s", 
+			expectedPointer, pointerOutput)
+	}
+
+	// Test case 3: Nil pointer
+	var nilPointer *TestStruct = nil
+	var nilBuf bytes.Buffer
+
+	// Call PrintEnv with a nil pointer
+	PrintEnv(nilPointer, &nilBuf)
+
+	// Get the output as a string
+	nilOutput := nilBuf.String()
+
+	// Expected output for nil pointer (just the shebang line)
+	expectedNil := "#!/usr/bin/env bash\n"
+
+	if nilOutput != expectedNil {
+		t.Errorf("PrintEnv output for nil pointer does not match expected.\nExpected:\n%s\nGot:\n%s", 
+			expectedNil, nilOutput)
+	}
 }
 
 func TestKVSliceSorting(t *testing.T) {