github.com/nozzle/golangci-lint@v1.49.0-nz3/pkg/golinters/lll.go (about)

     1  package golinters
     2  
     3  import (
     4  	"bufio"
     5  	"fmt"
     6  	"go/token"
     7  	"os"
     8  	"strings"
     9  	"sync"
    10  	"unicode/utf8"
    11  
    12  	"golang.org/x/tools/go/analysis"
    13  
    14  	"github.com/golangci/golangci-lint/pkg/config"
    15  	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
    16  	"github.com/golangci/golangci-lint/pkg/lint/linter"
    17  	"github.com/golangci/golangci-lint/pkg/result"
    18  )
    19  
    20  const lllName = "lll"
    21  
    22  //nolint:dupl
    23  func NewLLL(settings *config.LllSettings) *goanalysis.Linter {
    24  	var mu sync.Mutex
    25  	var resIssues []goanalysis.Issue
    26  
    27  	analyzer := &analysis.Analyzer{
    28  		Name: lllName,
    29  		Doc:  goanalysis.TheOnlyanalyzerDoc,
    30  		Run: func(pass *analysis.Pass) (interface{}, error) {
    31  			issues, err := runLll(pass, settings)
    32  			if err != nil {
    33  				return nil, err
    34  			}
    35  
    36  			if len(issues) == 0 {
    37  				return nil, nil
    38  			}
    39  
    40  			mu.Lock()
    41  			resIssues = append(resIssues, issues...)
    42  			mu.Unlock()
    43  
    44  			return nil, nil
    45  		},
    46  	}
    47  
    48  	return goanalysis.NewLinter(
    49  		lllName,
    50  		"Reports long lines",
    51  		[]*analysis.Analyzer{analyzer},
    52  		nil,
    53  	).WithIssuesReporter(func(*linter.Context) []goanalysis.Issue {
    54  		return resIssues
    55  	}).WithLoadMode(goanalysis.LoadModeSyntax)
    56  }
    57  
    58  func runLll(pass *analysis.Pass, settings *config.LllSettings) ([]goanalysis.Issue, error) {
    59  	fileNames := getFileNames(pass)
    60  
    61  	spaces := strings.Repeat(" ", settings.TabWidth)
    62  
    63  	var issues []goanalysis.Issue
    64  	for _, f := range fileNames {
    65  		lintIssues, err := getLLLIssuesForFile(f, settings.LineLength, spaces)
    66  		if err != nil {
    67  			return nil, err
    68  		}
    69  
    70  		for i := range lintIssues {
    71  			issues = append(issues, goanalysis.NewIssue(&lintIssues[i], pass))
    72  		}
    73  	}
    74  
    75  	return issues, nil
    76  }
    77  
    78  func getLLLIssuesForFile(filename string, maxLineLen int, tabSpaces string) ([]result.Issue, error) {
    79  	var res []result.Issue
    80  
    81  	f, err := os.Open(filename)
    82  	if err != nil {
    83  		return nil, fmt.Errorf("can't open file %s: %s", filename, err)
    84  	}
    85  	defer f.Close()
    86  
    87  	lineNumber := 1
    88  	scanner := bufio.NewScanner(f)
    89  	for scanner.Scan() {
    90  		line := scanner.Text()
    91  		line = strings.ReplaceAll(line, "\t", tabSpaces)
    92  		lineLen := utf8.RuneCountInString(line)
    93  		if lineLen > maxLineLen {
    94  			res = append(res, result.Issue{
    95  				Pos: token.Position{
    96  					Filename: filename,
    97  					Line:     lineNumber,
    98  				},
    99  				Text:       fmt.Sprintf("line is %d characters", lineLen),
   100  				FromLinter: lllName,
   101  			})
   102  		}
   103  		lineNumber++
   104  	}
   105  
   106  	if err := scanner.Err(); err != nil {
   107  		if err == bufio.ErrTooLong && maxLineLen < bufio.MaxScanTokenSize {
   108  			// scanner.Scan() might fail if the line is longer than bufio.MaxScanTokenSize
   109  			// In the case where the specified maxLineLen is smaller than bufio.MaxScanTokenSize
   110  			// we can return this line as a long line instead of returning an error.
   111  			// The reason for this change is that this case might happen with autogenerated files
   112  			// The go-bindata tool for instance might generate a file with a very long line.
   113  			// In this case, as it's an auto generated file, the warning returned by lll will
   114  			// be ignored.
   115  			// But if we return a linter error here, and this error happens for an autogenerated
   116  			// file the error will be discarded (fine), but all the subsequent errors for lll will
   117  			// be discarded for other files, and we'll miss legit error.
   118  			res = append(res, result.Issue{
   119  				Pos: token.Position{
   120  					Filename: filename,
   121  					Line:     lineNumber,
   122  					Column:   1,
   123  				},
   124  				Text:       fmt.Sprintf("line is more than %d characters", bufio.MaxScanTokenSize),
   125  				FromLinter: lllName,
   126  			})
   127  		} else {
   128  			return nil, fmt.Errorf("can't scan file %s: %s", filename, err)
   129  		}
   130  	}
   131  
   132  	return res, nil
   133  }