github.com/elek/golangci-lint@v1.42.2-0.20211208090441-c05b7fcb3a9a/pkg/golinters/gofumpt.go (about)

     1  package golinters
     2  
     3  import (
     4  	"bytes"
     5  	"fmt"
     6  	"io/ioutil"
     7  	"sync"
     8  
     9  	"github.com/pkg/errors"
    10  	"github.com/shazow/go-diff/difflib"
    11  	"golang.org/x/tools/go/analysis"
    12  	"mvdan.cc/gofumpt/format"
    13  
    14  	"github.com/elek/golangci-lint/pkg/config"
    15  	"github.com/elek/golangci-lint/pkg/golinters/goanalysis"
    16  	"github.com/elek/golangci-lint/pkg/lint/linter"
    17  )
    18  
    19  const gofumptName = "gofumpt"
    20  
    21  func NewGofumpt() *goanalysis.Linter {
    22  	var mu sync.Mutex
    23  	var resIssues []goanalysis.Issue
    24  	differ := difflib.New()
    25  
    26  	analyzer := &analysis.Analyzer{
    27  		Name: gofumptName,
    28  		Doc:  goanalysis.TheOnlyanalyzerDoc,
    29  	}
    30  	return goanalysis.NewLinter(
    31  		gofumptName,
    32  		"Gofumpt checks whether code was gofumpt-ed.",
    33  		[]*analysis.Analyzer{analyzer},
    34  		nil,
    35  	).WithContextSetter(func(lintCtx *linter.Context) {
    36  		settings := lintCtx.Settings().Gofumpt
    37  
    38  		options := format.Options{
    39  			LangVersion: getLangVersion(settings),
    40  			ExtraRules:  settings.ExtraRules,
    41  		}
    42  
    43  		analyzer.Run = func(pass *analysis.Pass) (interface{}, error) {
    44  			var fileNames []string
    45  			for _, f := range pass.Files {
    46  				pos := pass.Fset.PositionFor(f.Pos(), false)
    47  				fileNames = append(fileNames, pos.Filename)
    48  			}
    49  
    50  			var issues []goanalysis.Issue
    51  
    52  			for _, f := range fileNames {
    53  				input, err := ioutil.ReadFile(f)
    54  				if err != nil {
    55  					return nil, fmt.Errorf("unable to open file %s: %w", f, err)
    56  				}
    57  
    58  				output, err := format.Source(input, options)
    59  				if err != nil {
    60  					return nil, fmt.Errorf("error while running gofumpt: %w", err)
    61  				}
    62  
    63  				if !bytes.Equal(input, output) {
    64  					out := bytes.Buffer{}
    65  					_, err = out.WriteString(fmt.Sprintf("--- %[1]s\n+++ %[1]s\n", f))
    66  					if err != nil {
    67  						return nil, fmt.Errorf("error while running gofumpt: %w", err)
    68  					}
    69  
    70  					err = differ.Diff(&out, bytes.NewReader(input), bytes.NewReader(output))
    71  					if err != nil {
    72  						return nil, fmt.Errorf("error while running gofumpt: %w", err)
    73  					}
    74  
    75  					diff := out.String()
    76  					is, err := extractIssuesFromPatch(diff, lintCtx.Log, lintCtx, gofumptName)
    77  					if err != nil {
    78  						return nil, errors.Wrapf(err, "can't extract issues from gofumpt diff output %q", diff)
    79  					}
    80  
    81  					for i := range is {
    82  						issues = append(issues, goanalysis.NewIssue(&is[i], pass))
    83  					}
    84  				}
    85  			}
    86  
    87  			if len(issues) == 0 {
    88  				return nil, nil
    89  			}
    90  
    91  			mu.Lock()
    92  			resIssues = append(resIssues, issues...)
    93  			mu.Unlock()
    94  
    95  			return nil, nil
    96  		}
    97  	}).WithIssuesReporter(func(*linter.Context) []goanalysis.Issue {
    98  		return resIssues
    99  	}).WithLoadMode(goanalysis.LoadModeSyntax)
   100  }
   101  
   102  func getLangVersion(settings config.GofumptSettings) string {
   103  	if settings.LangVersion == "" {
   104  		// TODO: defaults to "1.15", in the future (v2) must be set by using build.Default.ReleaseTags like staticcheck.
   105  		return "1.15"
   106  	}
   107  	return settings.LangVersion
   108  }