feat: Use JSON tag for column name when applicable (#112)

Use JSON tag to define field name when applicable

Author: candiduslynx

codegen/golang.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"reflect"
+	"strings"
 	"text/template"
 	"unicode"
 
@@ -54,9 +55,9 @@ func valueToSchemaType(v reflect.Type) (schema.ValueType, error) {
 	}
 }
 
-func WithNameTransformer(transformer func(string) string) TableOptions {
+func WithNameTransformer(transformer func(field reflect.StructField) string) TableOptions {
 	return func(t *TableDefinition) {
-		t.Name = transformer(t.Name)
+		t.nameTransformer = transformer
 	}
 }
 
@@ -86,7 +87,11 @@ func WithUnwrapAllEmbeddedStructs() TableOptions {
 	}
 }
 
-func defaultTransformer(name string) string {
+func defaultTransformer(field reflect.StructField) string {
+	name := field.Name
+	if jsonTag := strings.Split(field.Tag.Get("json"), ",")[0]; len(jsonTag) > 0 {
+		name = jsonTag
+	}
 	return strcase.ToSnake(name)
 }
 
@@ -129,7 +134,7 @@ func (t *TableDefinition) ignoreField(field reflect.StructField) bool {
 	return len(field.Name) == 0 || unicode.IsLower(rune(field.Name[0])) || sliceContains(t.skipFields, field.Name)
 }
 
-func (t *TableDefinition) addColumnFromField(field reflect.StructField, parentFieldName string) {
+func (t *TableDefinition) addColumnFromField(field reflect.StructField, parent *reflect.StructField) {
 	if t.ignoreField(field) {
 		return
 	}
@@ -142,10 +147,10 @@ func (t *TableDefinition) addColumnFromField(field reflect.StructField, parentFi
 
 	// generate a PathResolver to use by default
 	pathResolver := fmt.Sprintf(`schema.PathResolver("%s")`, field.Name)
-	name := t.nameTransformer(field.Name)
-	if parentFieldName != "" {
-		pathResolver = fmt.Sprintf(`schema.PathResolver("%s.%s")`, parentFieldName, field.Name)
-		name = t.nameTransformer(parentFieldName) + "_" + name
+	name := t.nameTransformer(field)
+	if parent != nil {
+		pathResolver = fmt.Sprintf(`schema.PathResolver("%s.%s")`, parent.Name, field.Name)
+		name = t.nameTransformer(*parent) + "_" + name
 	}
 
 	column := ColumnDefinition{
@@ -181,16 +186,16 @@ func NewTableFromStruct(name string, obj interface{}, opts ...TableOptions) (*Ta
 
 		if t.shouldUnwrapField(field) {
 			unwrappedFields := t.getUnwrappedFields(field)
-			parentFieldName := ""
+			var parent *reflect.StructField
 			// For non embedded structs we need to add the parent field name to the path
 			if !field.Anonymous {
-				parentFieldName = field.Name
+				parent = &field
 			}
 			for _, f := range unwrappedFields {
-				t.addColumnFromField(f, parentFieldName)
+				t.addColumnFromField(f, parent)
 			}
 		} else {
-			t.addColumnFromField(field, "")
+			t.addColumnFromField(field, nil)
 		}
 	}
 

codegen/golang_test.go

@@ -31,6 +31,8 @@ type testStruct struct {
 	StringArrayCol []string   `json:"string_array_col,omitempty"`
 	TimeCol        time.Time  `json:"time_col,omitempty"`
 	TimePointerCol *time.Time `json:"time_pointer_col,omitempty"`
+	JSONTAG        *string    `json:"json_tag"`
+	NOJSONTAG      *string
 	*embeddedStruct
 }
 
@@ -90,6 +92,16 @@ var expectedColumns = []ColumnDefinition{
 		Type:     schema.TypeTimestamp,
 		Resolver: `schema.PathResolver("TimePointerCol")`,
 	},
+	{
+		Name:     "json_tag",
+		Type:     schema.TypeString,
+		Resolver: `schema.PathResolver("JSONTAG")`,
+	},
+	{
+		Name:     "nojsontag",
+		Type:     schema.TypeString,
+		Resolver: `schema.PathResolver("NOJSONTAG")`,
+	},
 }
 
 var expectedTestTable = TableDefinition{

codegen/table.go

@@ -1,6 +1,8 @@
 package codegen
 
 import (
+	"reflect"
+
 	"github.com/cloudquery/plugin-sdk/schema"
 )
 
@@ -20,7 +22,7 @@ type TableDefinition struct {
 	Multiplex                     string
 	PostResourceResolver          string
 	PreResourceResolver           string
-	nameTransformer               func(string) string
+	nameTransformer               func(reflect.StructField) string
 	skipFields                    []string
 	extraColumns                  ColumnDefinitions
 	structFieldsToUnwrap          []string