Merge 1271fbd into 1a871c1

utils.go

@@ -0,0 +1,50 @@
+package irc
+
+import (
+	"bytes"
+	"regexp"
+)
+
+var maskTranslations = map[byte]string{
+	'?': ".",
+	'*': ".*",
+}
+
+// MaskToRegex converts an irc mask to a go Regexp for more convenient
+// use. This should never return an error, but we have this here just
+// in case.
+func MaskToRegex(rawMask string) (*regexp.Regexp, error) {
+	input := bytes.NewBufferString(rawMask)
+
+	output := &bytes.Buffer{}
+	output.WriteByte('^')
+
+	for {
+		c, err := input.ReadByte()
+		if err != nil {
+			break
+		}
+
+		if c == '\\' {
+			c, err = input.ReadByte()
+			if err != nil {
+				output.WriteString(regexp.QuoteMeta("\\"))
+				break
+			}
+
+			if c == '?' || c == '*' || c == '\\' {
+				output.WriteString(regexp.QuoteMeta(string(c)))
+			} else {
+				output.WriteString(regexp.QuoteMeta("\\" + string(c)))
+			}
+		} else if trans, ok := maskTranslations[c]; ok {
+			output.WriteString(trans)
+		} else {
+			output.WriteString(regexp.QuoteMeta(string(c)))
+		}
+	}
+
+	output.WriteByte('$')
+
+	return regexp.Compile(output.String())
+}

utils_test.go

@@ -0,0 +1,63 @@
+package irc
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMaskToRegex(t *testing.T) {
+	t.Parallel()
+
+	var testCases = []struct {
+		Input  string
+		Expect string
+	}{
+		{ // Empty should be fine
+			Input:  "",
+			Expect: "^$",
+		},
+		{ // EVERYONE!
+			Input:  "*!*@*",
+			Expect: "^.*!.*@.*$",
+		},
+		{
+			Input:  "",
+			Expect: "^$",
+		},
+		{
+			Input:  "",
+			Expect: "^$",
+		},
+		{ // Escape the slash
+			Input:  "a\\\\b",
+			Expect: "^a\\\\b$",
+		},
+		{ // Escape a *
+			Input:  "a\\*b",
+			Expect: "^a\\*b$",
+		},
+		{ // Escape a ?
+			Input:  "a\\?b",
+			Expect: "^a\\?b$",
+		},
+		{ // Single slash in the middle of a string should be a slash
+			Input:  "a\\b",
+			Expect: "^a\\\\b$",
+		},
+		{ // Single slash should just match a single slash
+			Input:  "\\",
+			Expect: "^\\\\$",
+		},
+		{
+			Input:  "\\a?",
+			Expect: "^\\\\a.$",
+		},
+	}
+
+	for _, testCase := range testCases {
+		ret, err := MaskToRegex(testCase.Input)
+		assert.NoError(t, err)
+		assert.Equal(t, testCase.Expect, ret.String())
+	}
+}