go-enry/utils.go
Miguel Molina 8ff885a3a8
implement IsGenerated helper to filter out generated files
Closes #17

Implements the IsGenerated helper function to filter out generated
files using the rules and matchers in:
- https://github.com/github/linguist/blob/master/lib/linguist/generated.rb

Since the vast majority of matchers have very different logic, it cannot
be autogenerated directly from linguist like other logics in enry, so it's
translated by hand.

There are three different types of matchers in this implementation:
- By extension, which mark as generated based only in the extension. These
  are the fastest matchers, so they're done first.
- By file name, which matches patterns against the filename. These
  are performed in second place. Unlike linguist, we try to use string
  functions instead of regexps as much as possible.
- Finally, the rest of the matchers, which go into the content and try
  to identify if they're generated or not based on the content. Unlike
  linguist, we try to only read the content we need and not split it
  all unless it's necessary and use byte functions instead of regexps
  as much as possible.

Signed-off-by: Miguel Molina <miguel@erizocosmi.co>
2020-05-28 08:55:13 +02:00

134 lines
2.9 KiB
Go

package enry
import (
"bytes"
"path/filepath"
"strings"
"github.com/go-enry/go-enry/v2/data"
"github.com/go-enry/go-enry/v2/regex"
)
const binSniffLen = 8000
var configurationLanguages = map[string]struct{}{
"XML": {},
"JSON": {},
"TOML": {},
"YAML": {},
"INI": {},
"SQL": {},
}
// IsConfiguration tells if filename is in one of the configuration languages.
func IsConfiguration(path string) bool {
language, _ := GetLanguageByExtension(path)
_, is := configurationLanguages[language]
return is
}
// IsImage tells if a given file is an image (PNG, JPEG or GIF format).
func IsImage(path string) bool {
extension := filepath.Ext(path)
if extension == ".png" || extension == ".jpg" || extension == ".jpeg" || extension == ".gif" {
return true
}
return false
}
// GetMIMEType returns a MIME type of a given file based on its languages.
func GetMIMEType(path string, language string) string {
if mime, ok := data.LanguagesMime[language]; ok {
return mime
}
if IsImage(path) {
return "image/" + filepath.Ext(path)[1:]
}
return "text/plain"
}
// IsDocumentation returns whether or not path is a documentation path.
func IsDocumentation(path string) bool {
return matchRegexSlice(data.DocumentationMatchers, path)
}
// IsDotFile returns whether or not path has dot as a prefix.
func IsDotFile(path string) bool {
base := filepath.Base(filepath.Clean(path))
return strings.HasPrefix(base, ".") && base != "."
}
// IsVendor returns whether or not path is a vendor path.
func IsVendor(path string) bool {
return matchRegexSlice(data.VendorMatchers, path)
}
// IsTest returns whether or not path is a test path.
func IsTest(path string) bool {
return matchRegexSlice(data.TestMatchers, path)
}
// IsBinary detects if data is a binary value based on:
// http://git.kernel.org/cgit/git/git.git/tree/xdiff-interface.c?id=HEAD#n198
func IsBinary(data []byte) bool {
if len(data) > binSniffLen {
data = data[:binSniffLen]
}
if bytes.IndexByte(data, byte(0)) == -1 {
return false
}
return true
}
// GetColor returns a HTML color code of a given language.
func GetColor(language string) string {
if color, ok := data.LanguagesColor[language]; ok {
return color
}
if color, ok := data.LanguagesColor[GetLanguageGroup(language)]; ok {
return color
}
return "#cccccc"
}
func matchRegexSlice(exprs []regex.EnryRegexp, str string) bool {
for _, expr := range exprs {
if expr.MatchString(str) {
return true
}
}
return false
}
// IsGenerated returns whether the file with the given path and content is a
// generated file.
func IsGenerated(path string, content []byte) bool {
ext := strings.ToLower(filepath.Ext(path))
if _, ok := data.GeneratedCodeExtensions[ext]; ok {
return true
}
for _, m := range data.GeneratedCodeNameMatchers {
if m(path) {
return true
}
}
path = strings.ToLower(path)
for _, m := range data.GeneratedCodeMatchers {
if m(path, ext, content) {
return true
}
}
return false
}