feat(writer): enhance type conversion for PostgreSQL compatibility and add tests

pkg/pgsql/datatypes.go

@@ -4,31 +4,31 @@ import "strings"
 
 var GoToStdTypes = map[string]string{
 	"bool":            "boolean",
-	"int64":           "integer",
+	"int64":           "bigint",
 	"int":             "integer",
-	"int8":            "integer",
+	"int8":            "smallint",
-	"int16":           "integer",
+	"int16":           "smallint",
 	"int32":           "integer",
 	"uint":            "integer",
-	"uint8":           "integer",
+	"uint8":           "smallint",
-	"uint16":          "integer",
+	"uint16":          "smallint",
 	"uint32":          "integer",
-	"uint64":          "integer",
+	"uint64":          "bigint",
-	"uintptr":         "integer",
+	"uintptr":         "bigint",
-	"znullint64":      "integer",
+	"znullint64":      "bigint",
 	"znullint32":      "integer",
-	"znullbyte":       "integer",
+	"znullbyte":       "smallint",
 	"float64":         "double",
 	"float32":         "double",
 	"complex64":       "double",
 	"complex128":      "double",
 	"customfloat64":   "double",
-	"string":          "string",
+	"string":          "text",
-	"Pointer":         "integer",
+	"Pointer":         "bigint",
 	"[]byte":          "blob",
-	"customdate":      "string",
+	"customdate":      "date",
-	"customtime":      "string",
+	"customtime":      "time",
-	"customtimestamp": "string",
+	"customtimestamp": "timestamp",
 	"sqlfloat64":      "double",
 	"sqlfloat16":      "double",
 	"sqluuid":         "uuid",
@@ -36,9 +36,9 @@ var GoToStdTypes = map[string]string{
 	"sqljson":         "json",
 	"sqlint64":        "bigint",
 	"sqlint32":        "integer",
-	"sqlint16":        "integer",
+	"sqlint16":        "smallint",
 	"sqlbool":         "boolean",
-	"sqlstring":       "string",
+	"sqlstring":       "text",
 	"nullablejsonb":   "jsonb",
 	"nullablejson":    "json",
 	"nullableuuid":    "uuid",
@@ -67,7 +67,7 @@ var GoToPGSQLTypes = map[string]string{
 	"float32":         "real",
 	"complex64":       "double precision",
 	"complex128":      "double precision",
-	"customfloat64":   "double precisio",
+	"customfloat64":   "double precision",
 	"string":          "text",
 	"Pointer":         "bigint",
 	"[]byte":          "bytea",
@@ -81,9 +81,9 @@ var GoToPGSQLTypes = map[string]string{
 	"sqljson":         "json",
 	"sqlint64":        "bigint",
 	"sqlint32":        "integer",
-	"sqlint16":        "integer",
+	"sqlint16":        "smallint",
 	"sqlbool":         "boolean",
-	"sqlstring":       "string",
+	"sqlstring":       "text",
 	"nullablejsonb":   "jsonb",
 	"nullablejson":    "json",
 	"nullableuuid":    "uuid",

pkg/writers/pgsql/migration_writer.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
 )
 
@@ -335,7 +336,7 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 				SchemaName: schema.Name,
 				TableName:  modelTable.Name,
 				ColumnName: modelCol.Name,
-				ColumnType: modelCol.Type,
+				ColumnType: pgsql.ConvertSQLType(modelCol.Type),
 				Default:    defaultVal,
 				NotNull:    modelCol.NotNull,
 			})
@@ -359,7 +360,7 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 					SchemaName: schema.Name,
 					TableName:  modelTable.Name,
 					ColumnName: modelCol.Name,
-					NewType:    modelCol.Type,
+					NewType:    pgsql.ConvertSQLType(modelCol.Type),
 				})
 				if err != nil {
 					return nil, err

pkg/writers/pgsql/writer.go

@@ -13,6 +13,7 @@ import (
 	"github.com/jackc/pgx/v5"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
 )
 
@@ -332,15 +333,16 @@ func (w *Writer) generateCreateTableStatement(schema *models.Schema, table *mode
 func (w *Writer) generateColumnDefinition(col *models.Column) string {
 	parts := []string{col.SQLName()}
 
-	// Type with length/precision
+	// Type with length/precision - convert to valid PostgreSQL type
-	typeStr := col.Type
+	baseType := pgsql.ConvertSQLType(col.Type)
+	typeStr := baseType
 	if col.Length > 0 && col.Precision == 0 {
-		typeStr = fmt.Sprintf("%s(%d)", col.Type, col.Length)
+		typeStr = fmt.Sprintf("%s(%d)", baseType, col.Length)
 	} else if col.Precision > 0 {
 		if col.Scale > 0 {
-			typeStr = fmt.Sprintf("%s(%d,%d)", col.Type, col.Precision, col.Scale)
+			typeStr = fmt.Sprintf("%s(%d,%d)", baseType, col.Precision, col.Scale)
 		} else {
-			typeStr = fmt.Sprintf("%s(%d)", col.Type, col.Precision)
+			typeStr = fmt.Sprintf("%s(%d)", baseType, col.Precision)
 		}
 	}
 	parts = append(parts, typeStr)
@@ -488,7 +490,7 @@ func (w *Writer) writeCreateTables(schema *models.Schema) error {
 		columnDefs := make([]string, 0, len(columns))
 
 		for _, col := range columns {
-			colDef := fmt.Sprintf("  %s %s", col.SQLName(), col.Type)
+			colDef := fmt.Sprintf("  %s %s", col.SQLName(), pgsql.ConvertSQLType(col.Type))
 
 			// Add default value if present
 			if col.Default != nil && col.Default != "" {

pkg/writers/pgsql/writer_test.go

@@ -241,3 +241,67 @@ func TestIsIntegerType(t *testing.T) {
 		}
 	}
 }
+
+func TestTypeConversion(t *testing.T) {
+	// Test that invalid Go types are converted to valid PostgreSQL types
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	// Create a test table with Go types instead of SQL types
+	table := models.InitTable("test_types", "public")
+
+	// Add columns with Go types (invalid for PostgreSQL)
+	stringCol := models.InitColumn("name", "test_types", "public")
+	stringCol.Type = "string" // Should be converted to "text"
+	table.Columns["name"] = stringCol
+
+	int64Col := models.InitColumn("big_id", "test_types", "public")
+	int64Col.Type = "int64" // Should be converted to "bigint"
+	table.Columns["big_id"] = int64Col
+
+	int16Col := models.InitColumn("small_id", "test_types", "public")
+	int16Col.Type = "int16" // Should be converted to "smallint"
+	table.Columns["small_id"] = int16Col
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	// Create writer with output to buffer
+	var buf bytes.Buffer
+	options := &writers.WriterOptions{}
+	writer := NewWriter(options)
+	writer.writer = &buf
+
+	// Write the database
+	err := writer.WriteDatabase(db)
+	if err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+
+	// Print output for debugging
+	t.Logf("Generated SQL:\n%s", output)
+
+	// Verify that Go types were converted to PostgreSQL types
+	if strings.Contains(output, "string") {
+		t.Errorf("Output contains 'string' type - should be converted to 'text'\nFull output:\n%s", output)
+	}
+	if strings.Contains(output, "int64") {
+		t.Errorf("Output contains 'int64' type - should be converted to 'bigint'\nFull output:\n%s", output)
+	}
+	if strings.Contains(output, "int16") {
+		t.Errorf("Output contains 'int16' type - should be converted to 'smallint'\nFull output:\n%s", output)
+	}
+
+	// Verify correct PostgreSQL types are present
+	if !strings.Contains(output, "text") {
+		t.Errorf("Output missing 'text' type (converted from 'string')\nFull output:\n%s", output)
+	}
+	if !strings.Contains(output, "bigint") {
+		t.Errorf("Output missing 'bigint' type (converted from 'int64')\nFull output:\n%s", output)
+	}
+	if !strings.Contains(output, "smallint") {
+		t.Errorf("Output missing 'smallint' type (converted from 'int16')\nFull output:\n%s", output)
+	}
+}