Add model generator based on AST

cmd/main.go

@@ -21,10 +21,9 @@ func main() {
 	}
 	root_cmd.AddCommand(sqlite_lint)
 	root_cmd.AddCommand(cmd_init)
+	root_cmd.AddCommand(generate_model)
 	if err := root_cmd.Execute(); err != nil {
 		fmt.Println(RED + err.Error() + RESET)
 		os.Exit(1)
 	}
 }
-
-// Subcommand "generate_models"

cmd/subcmd_generate_models.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/printer"
+	"go/token"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen/modelgenerate"
+	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
+)
+
+var ErrNoSuchTable = errors.New("no such table")
+
+var generate_model = &cobra.Command{
+	Use:   "generate <model_name>",
+	Short: "Generate a model type",
+
+	Args: cobra.ExactArgs(1),
+
+	RunE: func(cmd *cobra.Command, args []string) error {
+		path := Must(cmd.Flags().GetString("schema"))
+		modname := Must(cmd.Flags().GetString("modname"))
+		schema_sql, err := os.ReadFile(path)
+		if err != nil {
+			return fmt.Errorf("reading path %s: %w", path, err)
+		}
+		db := schema.InitDB(string(schema_sql))
+		tables := schema.SchemaFromDB(db).Tables
+		table, isOk := tables[args[0]]
+		if !isOk {
+			return ErrNoSuchTable
+		}
+
+		fset := token.NewFileSet()
+
+		if Must(cmd.Flags().GetBool("test")) {
+			file2 := modelgenerate.GenerateModelTestAST(table, modname)
+			PanicIf(printer.Fprint(os.Stdout, fset, file2))
+		} else {
+			file := &ast.File{
+				Name: ast.NewIdent("db"), // TODO: parameterize
+
+				Decls: []ast.Decl{
+					&ast.GenDecl{
+						Tok: token.IMPORT,
+						Specs: []ast.Spec{
+							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"database/sql"`}},
+							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"errors"`}},
+							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"fmt"`}},
+							&ast.ImportSpec{
+								Name: ast.NewIdent("."),
+								Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
+							},
+						},
+					},
+					modelgenerate.GenerateIDType(table),
+					modelgenerate.GenerateModelAST(table),
+					modelgenerate.GenerateSaveItemFunc(table),
+					modelgenerate.GenerateGetItemByIDFunc(table),
+					modelgenerate.GenerateDeleteItemFunc(table),
+				},
+			}
+
+			PanicIf(printer.Fprint(os.Stdout, fset, file))
+		}
+
+		return nil
+	},
+}
+
+func init() {
+	generate_model.Flags().String("schema", "pkg/db/schema.sql", "Path to SQL schema file")
+	generate_model.Flags().String("modname", "mymodule", "Name of project's Go module (TODO: detect automatically)")
+	generate_model.Flags().Bool("test", false, "Generate test file instead of regular file")
+}