From aec3b8d204dd8b4f9308f536e9b5eefcf966f86e Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Wed, 2 May 2018 22:30:43 +0300
Subject: Add tests for PushRule.Match and fork glob to make it compatible with
 the spec

---
 lib/glob/glob.go | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 lib/glob/glob.go

(limited to 'lib/glob/glob.go')

diff --git a/lib/glob/glob.go b/lib/glob/glob.go
new file mode 100644
index 0000000..c270dbc
--- /dev/null
+++ b/lib/glob/glob.go
@@ -0,0 +1,108 @@
+// Package glob provides objects for matching strings with globs
+package glob
+
+import "regexp"
+
+// Glob is a wrapper of *regexp.Regexp.
+// It should contain a glob expression compiled into a regular expression.
+type Glob struct {
+	*regexp.Regexp
+}
+
+// Compile a takes a glob expression as a string and transforms it
+// into a *Glob object (which is really just a regular expression)
+// Compile also returns a possible error.
+func Compile(pattern string) (*Glob, error) {
+	r, err := globToRegex(pattern)
+	return &Glob{r}, err
+}
+
+func globToRegex(glob string) (*regexp.Regexp, error) {
+	regex := ""
+	inGroup := 0
+	inClass := 0
+	firstIndexInClass := -1
+	arr := []byte(glob)
+
+	hasGlobCharacters := false
+
+	for i := 0; i < len(arr); i++ {
+		ch := arr[i]
+
+		switch ch {
+		case '\\':
+			i++
+			if i >= len(arr) {
+				regex += "\\"
+			} else {
+				next := arr[i]
+				switch next {
+				case ',':
+					// Nothing
+				case 'Q', 'E':
+					regex += "\\\\"
+				default:
+					regex += "\\"
+				}
+				regex += string(next)
+			}
+		case '*':
+			if inClass == 0 {
+				regex += ".*"
+			} else {
+				regex += "*"
+			}
+			hasGlobCharacters = true
+		case '?':
+			if inClass == 0 {
+				regex += "."
+			} else {
+				regex += "?"
+			}
+			hasGlobCharacters = true
+		case '[':
+			inClass++
+			firstIndexInClass = i + 1
+			regex += "["
+			hasGlobCharacters = true
+		case ']':
+			inClass--
+			regex += "]"
+		case '.', '(', ')', '+', '|', '^', '$', '@', '%':
+			if inClass == 0 || (firstIndexInClass == i && ch == '^') {
+				regex += "\\"
+			}
+			regex += string(ch)
+			hasGlobCharacters = true
+		case '!':
+			if firstIndexInClass == i {
+				regex += "^"
+			} else {
+				regex += "!"
+			}
+			hasGlobCharacters = true
+		case '{':
+			inGroup++
+			regex += "("
+			hasGlobCharacters = true
+		case '}':
+			inGroup--
+			regex += ")"
+		case ',':
+			if inGroup > 0 {
+				regex += "|"
+				hasGlobCharacters = true
+			} else {
+				regex += ","
+			}
+		default:
+			regex += string(ch)
+		}
+	}
+
+	if hasGlobCharacters {
+		return regexp.Compile("^" + regex + "$")
+	} else {
+		return regexp.Compile(regex)
+	}
+}
-- 
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