From 842149494b5a082612cc4ebb24e869d6a5d646f5 Mon Sep 17 00:00:00 2001
From: Nikhil Narula <nikhil.narula@blueapron.com>
Date: Wed, 22 Feb 2017 17:05:25 -0500
Subject: [PATCH] Initial implementation of ignorefile

---
 main.go | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 main.go

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..754c97e
--- /dev/null
+++ b/main.go
@@ -0,0 +1,104 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/docker/docker/pkg/fileutils"
+)
+
+func ReadAll(reader io.Reader) ([]string, error) {
+	if reader == nil {
+		return nil, nil
+	}
+
+	scanner := bufio.NewScanner(reader)
+	var excludes []string
+	currentLine := 0
+
+	utf8bom := []byte{0xEF, 0xBB, 0xBF}
+	for scanner.Scan() {
+		scannedBytes := scanner.Bytes()
+		// We trim UTF8 BOM
+		if currentLine == 0 {
+			scannedBytes = bytes.TrimPrefix(scannedBytes, utf8bom)
+		}
+		pattern := string(scannedBytes)
+		currentLine++
+		// Lines starting with # (comments) are ignored before processing
+		if strings.HasPrefix(pattern, "#") {
+			continue
+		}
+		pattern = strings.TrimSpace(pattern)
+		if pattern == "" {
+			continue
+		}
+		pattern = filepath.Clean(pattern)
+		pattern = filepath.ToSlash(pattern)
+		excludes = append(excludes, pattern)
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("Error reading ignore file: %v", err)
+	}
+	return excludes, nil
+}
+
+func Filter(ignoreFile string, filesToTest []string) ([]string, error) {
+	f, err := os.Open(ignoreFile)
+	// Note that a missing ignore file isn't treated as an error
+	if err != nil {
+		if os.IsNotExist(err) {
+			return filesToTest, nil
+		}
+		return nil, err
+	}
+	excludes, _ := ReadAll(f)
+	f.Close()
+
+        unignored := []string{}
+	for _, fileToTest := range filesToTest {
+		shouldIgnore, _ := fileutils.Matches(fileToTest, excludes)
+		if !shouldIgnore {
+			unignored = append(unignored, fileToTest)
+		}
+	}
+	return unignored, nil
+}
+
+func main() {
+	ignoreFile := flag.String("f", "", "ignore file to parse and test against")
+	flag.Parse()
+	if *ignoreFile == "" {
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	files := []string{}
+	if flag.NArg() == 0 {
+		// read from stdin
+		scanner := bufio.NewScanner(os.Stdin)
+		scanner.Split(bufio.ScanWords)
+		for scanner.Scan() {
+			files = append(files, scanner.Text())
+		}
+	} else {
+		for _, val := range flag.Args() {
+			files = append(files, val)
+		}
+	}
+
+	filteredFiles, err := Filter(*ignoreFile, files)
+	if err != nil {
+		fmt.Errorf("Error filtering test files: %v", err)
+		os.Exit(1)
+	}
+	for _, file := range filteredFiles {
+		fmt.Println(file)
+	}
+}