chore: Fix case formatting of generated TF model fields not matching API fields (#3740)

Author: manupedrozo

internal/common/autogen/marshal.go

@@ -8,6 +8,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework-jsontypes/jsontypes"
 	"github.com/hashicorp/terraform-plugin-framework/attr"
 	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/mongodb/terraform-provider-mongodbatlas/internal/common/autogen/stringcase"
 )
 
 const (
@@ -62,7 +63,7 @@ func marshalAttrs(valModel reflect.Value, isUpdate bool) (map[string]any, error)
 }
 
 func marshalAttr(attrNameModel string, attrValModel reflect.Value, objJSON map[string]any, isUpdate, includeNullOnUpdate bool) error {
-	attrNameJSON := toJSONName(attrNameModel)
+	attrNameJSON := stringcase.Uncapitalize(attrNameModel)
 	obj, ok := attrValModel.Interface().(attr.Value)
 	if !ok {
 		panic("marshal expects only Terraform types in the model")
@@ -141,9 +142,9 @@ func getMapAttr(elms map[string]attr.Value, keepKeyCase bool) (any, error) {
 			return nil, err
 		}
 		if valChild != nil {
-			nameJSON := toJSONName(name)
-			if keepKeyCase {
-				nameJSON = name
+			nameJSON := name
+			if !keepKeyCase {
+				nameJSON = stringcase.ToCamelCase(name)
 			}
 			objJSON[nameJSON] = valChild
 		}

internal/common/autogen/name.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"regexp"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/huandu/xstrings"
 )
@@ -46,3 +48,39 @@ func FromCamelCase(input string) SnakeCaseString {
 
 	return SnakeCaseString(strings.ToLower(insertedUnderscores))
 }
+
+func ToCamelCase(str string) string {
+	return xstrings.ToCamelCase(str)
+}
+
+func ToSnakeCase(str string) string {
+	return xstrings.ToSnakeCase(str)
+}
+
+func Capitalize(str string) string {
+	return capitalization(str, true)
+}
+
+func Uncapitalize(str string) string {
+	return capitalization(str, false)
+}
+
+func capitalization(str string, capitalize bool) string {
+	if str == "" {
+		return str
+	}
+
+	first, size := utf8.DecodeRuneInString(str)
+	if first == utf8.RuneError {
+		return str
+	}
+
+	builder := &strings.Builder{}
+	if capitalize {
+		builder.WriteRune(unicode.ToUpper(first))
+	} else {
+		builder.WriteRune(unicode.ToLower(first))
+	}
+	builder.WriteString(str[size:])
+	return builder.String()
+}

tools/codegen/stringcase/string_case.go renamed to internal/common/autogen/stringcase/string_case.go

@@ -0,0 +1,99 @@
+package stringcase_test
+
+import (
+	"testing"
+
+	"github.com/mongodb/terraform-provider-mongodbatlas/internal/common/autogen/stringcase"
+)
+
+func TestCapitalize(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "Non capitalized to capitalized",
+			input:    "toCaps",
+			expected: "ToCaps",
+		},
+		{
+			name:     "Already capitalized does nothing",
+			input:    "ToCaps",
+			expected: "ToCaps",
+		},
+		{
+			name:     "Single char capitalizes",
+			input:    "c",
+			expected: "C",
+		},
+		{
+			name:     "Non-capitalizable does nothing",
+			input:    "_",
+			expected: "_",
+		},
+		{
+			name:     "Empty does nothing",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "Invalid utf8 does nothing",
+			input:    string([]byte{0xFF}),
+			expected: string([]byte{0xFF}),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if actual := stringcase.Capitalize(tt.input); actual != tt.expected {
+				t.Errorf("Capitalize() returned %v, expected %v", actual, tt.expected)
+			}
+		})
+	}
+}
+
+func TestUncapitalize(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "Capitalized to non capitalized",
+			input:    "FromCaps",
+			expected: "fromCaps",
+		},
+		{
+			name:     "Non capitalized does nothing",
+			input:    "fromCaps",
+			expected: "fromCaps",
+		},
+		{
+			name:     "Single char uncapitalizes",
+			input:    "C",
+			expected: "c",
+		},
+		{
+			name:     "Non-uncapitalizable does nothing",
+			input:    "_",
+			expected: "_",
+		},
+		{
+			name:     "Empty does nothing",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "Invalid utf8 does nothing",
+			input:    string([]byte{0xFF}),
+			expected: string([]byte{0xFF}),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if actual := stringcase.Uncapitalize(tt.input); actual != tt.expected {
+				t.Errorf("Uncapitalize() returned %v, expected %v", actual, tt.expected)
+			}
+		})
+	}
+}

internal/common/autogen/stringcase/string_case_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework-jsontypes/jsontypes"
 	"github.com/hashicorp/terraform-plugin-framework/attr"
 	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/mongodb/terraform-provider-mongodbatlas/internal/common/autogen/stringcase"
 )
 
 // Unmarshal gets a JSON (e.g. from an Atlas response) and unmarshals it into a Terraform model.
@@ -45,7 +46,7 @@ func unmarshalAttrs(objJSON map[string]any, model any) error {
 }
 
 func unmarshalAttr(attrNameJSON string, attrObjJSON any, valModel reflect.Value) error {
-	attrNameModel := toTfModelName(attrNameJSON)
+	attrNameModel := stringcase.Capitalize(attrNameJSON)
 	fieldModel := valModel.FieldByName(attrNameModel)
 	if !fieldModel.CanSet() {
 		return nil // skip fields that cannot be set, are invalid or not found
@@ -75,7 +76,7 @@ func setAttrTfModel(name string, field reflect.Value, val attr.Value) error {
 }
 
 func setObjElmAttrModel(name string, value any, mapAttrs map[string]attr.Value, mapTypes map[string]attr.Type) error {
-	nameChildTf := toTfSchemaName(name)
+	nameChildTf := stringcase.ToSnakeCase(name)
 	valueType, found := mapTypes[nameChildTf]
 	if !found {
 		return nil // skip attributes that are not in the model
@@ -91,7 +92,7 @@ func setObjElmAttrModel(name string, value any, mapAttrs map[string]attr.Value,
 }
 
 func getTfAttr(value any, valueType attr.Type, oldVal attr.Value, name string) (attr.Value, error) {
-	nameErr := toTfSchemaName(name)
+	nameErr := stringcase.ToSnakeCase(name)
 	switch v := value.(type) {
 	case string:
 		if valueType == types.StringType {
@@ -164,7 +165,7 @@ func getTfAttr(value any, valueType attr.Type, oldVal attr.Value, name string) (
 }
 
 func errUnmarshal(value any, valueType attr.Type, typeReceived, name string) error {
-	nameErr := toTfSchemaName(name)
+	nameErr := stringcase.ToSnakeCase(name)
 	parts := strings.Split(reflect.TypeOf(valueType).String(), ".")
 	typeErr := parts[len(parts)-1]
 	return fmt.Errorf("unmarshal of attribute %s expects type %s but got %s with value: %v", nameErr, typeErr, typeReceived, value)

internal/common/autogen/unmarshal.go

@@ -43,7 +43,7 @@ func TestAccClusterAPI_basic(t *testing.T) {
 				ImportStateVerifyIdentifierAttribute: "name",
 				ImportStateVerifyIgnore: []string{
 					"retain_backups_enabled",   // This field is TF specific and not returned by Atlas, so Import can't fill it in.
-					"mongo_db_major_version",   // Risks plan change of 8 --> 8.0 (always normalized to `major.minor`)
+					"mongo_dbmajor_version",    // Risks plan change of 8 --> 8.0 (always normalized to `major.minor`)
 					"state_name",               // Cluster state can change from IDLE to UPDATING and risks making the test flaky
 					"delete_on_create_timeout", // This field is TF specific and not returned by Atlas, so Import can't fill it in.
 				},