Fixed format string parsing

CHANGELOG.md

@@ -9,6 +9,9 @@
 * Fixed color's hex value rounding error.  
   [Yusuke Onishi](https://github.com/yusuke024)
   [#19](https://github.com/SwiftGen/SwiftGenKit/pull/19)
+* Improved format string regex to handle escaped "%"s that precede a variable.  
+  [Tamas Lustyik](https://github.com/lvsti)
+  [#29](https://github.com/SwiftGen/SwiftGenKit/pull/29)
 
 ### Breaking Changes
 

Sources/Parsers/StringsFileParser.swift

@@ -124,7 +124,7 @@ public final class StringsFileParser {
 
     do {
       return try NSRegularExpression(
-        pattern: "(?<!%)%\(position)\(precision)(@|\(pattern_int)|\(pattern_float)|[csp])",
+        pattern: "(?:^|(?<!%)(?:%%)*)%\(position)\(precision)(@|\(pattern_int)|\(pattern_float)|[csp])",
         options: [.caseInsensitive]
       )
     } catch {

Tests/SwiftGenKitTests/StringParserTests.swift

@@ -50,10 +50,15 @@ class StringParserTests: XCTestCase {
     XCTAssertEqual(placeholders, [.unknown, .int, .object, .float, .char])
   }
 
-  func testParseEscapePercentSign() {
+  func testParseEvenEscapePercentSign() {
     let placeholders = StringsFileParser.PlaceholderType.placeholders(fromFormat: "%%foo")
-    // Must NOT map to [.Float]
+    // Must NOT map to [.float]
     XCTAssertEqual(placeholders, [])
   }
 
+  func testParseOddEscapePercentSign() {
+    let placeholders = StringsFileParser.PlaceholderType.placeholders(fromFormat: "%%%foo")
+    // Should map to [.float]
+    XCTAssertEqual(placeholders, [.float])
+  }
 }

Tests/SwiftGenKitTests/StringsTests.swift

@@ -14,7 +14,6 @@ import SwiftGenKit
  */
 
 class StringsTests: XCTestCase {
-
   func testEmpty() {
     let parser = StringsFileParser()