Function generateConstraints

scripts/dbgen/constraint.go:84–141

generateConstraints does the following: 1. Read the dump.sql file 2. Parse the file into each query 3. Pass each query to the constraintFn function 4. Generate the enum from the returned constraints 5. Write the generated code to the output path

(dumpPath, outputPath string, outputConstraintType constraintType, fn queryToConstraintsFn)

//  4. Generate the enum from the returned constraints
//  5. Write the generated code to the output path
func generateConstraints(dumpPath, outputPath string, outputConstraintType constraintType, fn queryToConstraintsFn) error {
	dump, err := os.Open(dumpPath)
	if err != nil {
		return err
	}
	defer dump.Close()

	var allConstraints []constraint

	dumpScanner := bufio.NewScanner(dump)
	query := ""
	for dumpScanner.Scan() {
		line := strings.TrimSpace(dumpScanner.Text())
		switch {
		case strings.HasPrefix(line, "--"):
		case line == "":
		case strings.HasSuffix(line, ";"):
			query += line
			newConstraints, err := fn(query)
			query = ""
			if err != nil {
				return xerrors.Errorf("process query %q: %w", query, err)
			}
			allConstraints = append(allConstraints, newConstraints...)
		default:
			query += line + " "
		}
	}
	if err = dumpScanner.Err(); err != nil {
		return err
	}

	s := &bytes.Buffer{}

	_, _ = fmt.Fprintf(s, `// Code generated by scripts/dbgen/main.go. DO NOT EDIT.
package database

// %[1]s represents a named %[2]s constraint on a table.
type %[1]s string

// %[1]s enums.
const (
`, outputConstraintType.goType(), outputConstraintType.goTypeDescriptionPart())

	for _, c := range allConstraints {
		constName := outputConstraintType.goEnumNamePrefix() + nameFromSnakeCase(c.name)
		_, _ = fmt.Fprintf(s, "\t%[1]s %[2]s = %[3]q // %[4]s\n", constName, outputConstraintType.goType(), c.name, c.comment)
	}
	_, _ = fmt.Fprint(s, ")\n")

	data, err := imports.Process(outputPath, s.Bytes(), &imports.Options{
		Comments: true,
	})
	if err != nil {
		return err
	}
	return atomicwrite.File(outputPath, data)
}