github.com/nikron/prototool@v1.3.0/internal/format/transformer.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package format
    22  
    23  import (
    24  	"bytes"
    25  	"fmt"
    26  	"strings"
    27  
    28  	"github.com/emicklei/proto"
    29  	"github.com/uber/prototool/internal/text"
    30  	"go.uber.org/zap"
    31  )
    32  
    33  type transformer struct {
    34  	logger *zap.Logger
    35  	fix    bool
    36  }
    37  
    38  func newTransformer(options ...TransformerOption) *transformer {
    39  	transformer := &transformer{
    40  		logger: zap.NewNop(),
    41  	}
    42  	for _, option := range options {
    43  		option(transformer)
    44  	}
    45  	return transformer
    46  }
    47  
    48  func (t *transformer) Transform(filename string, data []byte) ([]byte, []*text.Failure, error) {
    49  	descriptor, err := proto.NewParser(bytes.NewReader(data)).Parse()
    50  	if err != nil {
    51  		return nil, nil, err
    52  	}
    53  	descriptor.Filename = filename
    54  
    55  	firstPassVisitor := newFirstPassVisitor(filename, t.fix)
    56  	for _, element := range descriptor.Elements {
    57  		element.Accept(firstPassVisitor)
    58  	}
    59  	failures := firstPassVisitor.Do()
    60  	buffer := bytes.NewBuffer(nil)
    61  	buffer.Write(firstPassVisitor.Bytes())
    62  
    63  	syntaxVersion := 2
    64  	if firstPassVisitor.Syntax != nil && firstPassVisitor.Syntax.Value != "" {
    65  		switch firstPassVisitor.Syntax.Value {
    66  		case "proto2":
    67  			// nothing
    68  		case "proto3":
    69  			syntaxVersion = 3
    70  		default:
    71  			return nil, nil, fmt.Errorf("unknown syntax: %s", firstPassVisitor.Syntax.Value)
    72  		}
    73  	}
    74  
    75  	mainVisitor := newMainVisitor(syntaxVersion == 2)
    76  	for _, element := range descriptor.Elements {
    77  		element.Accept(mainVisitor)
    78  	}
    79  	failures = append(failures, mainVisitor.Do()...)
    80  	buffer.Write(mainVisitor.Bytes())
    81  
    82  	text.SortFailures(failures)
    83  
    84  	// TODO: expensive
    85  	s := strings.TrimSpace(buffer.String())
    86  	if len(s) > 0 {
    87  		return []byte(s + "\n"), failures, nil
    88  	}
    89  	return nil, failures, nil
    90  }