revive/linter/linter.go

package linter

import (
	"bufio"
	"bytes"
	"fmt"
	"go/token"
)

// ReadFile defines an abstraction for reading files.
type ReadFile func(path string) (result []byte, err error)

type disabledIntervalsMap = map[string][]DisabledInterval

// Linter is used for linting set of files.
type Linter struct {
	reader ReadFile
}

// New creates a new Linter
func New(reader ReadFile) Linter {
	return Linter{reader: reader}
}

var (
	genHdr = []byte("// Code generated ")
	genFtr = []byte(" DO NOT EDIT.")
)

// isGenerated reports whether the source file is generated code
// according the rules from https://golang.org/s/generatedcode.
// This is inherited from the original linter.
func isGenerated(src []byte) bool {
	sc := bufio.NewScanner(bytes.NewReader(src))
	for sc.Scan() {
		b := sc.Bytes()
		if bytes.HasPrefix(b, genHdr) && bytes.HasSuffix(b, genFtr) && len(b) >= len(genHdr)+len(genFtr) {
			return true
		}
	}
	return false
}

// Lint lints a set of files with the specified rule.
func (l *Linter) Lint(filenames []string, ruleSet []Rule, rulesConfig RulesConfig) ([]Failure, error) {
	pkg := &Package{
		Fset:  token.NewFileSet(),
		Files: map[string]*File{},
	}
	var pkgName string
	for _, filename := range filenames {
		content, err := l.reader(filename)
		if err != nil {
			return nil, err
		}
		if isGenerated(content) {
			continue
		}

		file, err := NewFile(filename, content, pkg)
		if err != nil {
			return nil, err
		}

		if pkgName == "" {
			pkgName = file.GetAST().Name.Name
		} else if file.GetAST().Name.Name != pkgName {
			return nil, fmt.Errorf("%s is in package %s, not %s", filename, file.GetAST().Name.Name, pkgName)
		}

		pkg.Files[filename] = file
	}

	return pkg.lint(ruleSet, rulesConfig), nil
}