Test Extract Card Number From Text

1- Move two methods "ExtractCreditCardNumber" and
   "SubstituteSimilarCharactersInRecognizedText" from mediator to
    Util file.
2- Write a unit test for the two methods.

Change-Id: Ie6e191cf06e4ae23d9993ded738dc374ec1c8790
Bug: 984545
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1782802Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Commit-Queue: Reda Tawfik <redatawfik@google.com>
Cr-Commit-Position: refs/heads/master@{#694756}

ios/chrome/browser/ui/settings/credit_card_scanner/credit_card_scanner_mediator.mm

@@ -148,79 +148,8 @@ using base::UserMetricsAction;
     self.expirationYear = [@([components year]) stringValue];
   }
   if (!self.cardNumber) {
-    self.cardNumber = [self extractCreditCardNumber:text];
+    self.cardNumber = ios::ExtractCreditCardNumber(text);
   }
 }
 
-// Extracts credit card number from |string|.
-- (NSString*)extractCreditCardNumber:(NSString*)string {
-  NSString* text = [[NSString alloc] initWithString:string];
-  // Strip whitespaces and symbols.
-  NSArray* ignoreSymbols = @[ @" ", @"/", @"-", @".", @":", @"\\" ];
-  for (NSString* symbol in ignoreSymbols) {
-    text = [text stringByReplacingOccurrencesOfString:symbol withString:@""];
-  }
-
-  // Matches strings which have 13-19 characters between the start(^) and the
-  // end($) of the line.
-  NSString* pattern = @"^(\\w{13,19})$";
-
-  NSError* error;
-  NSRegularExpression* regex = [[NSRegularExpression alloc]
-      initWithPattern:pattern
-              options:NSRegularExpressionAllowCommentsAndWhitespace
-                error:&error];
-
-  NSRange rangeOfText = NSMakeRange(0, [text length]);
-  NSTextCheckingResult* match = [regex firstMatchInString:text
-                                                  options:0
-                                                    range:rangeOfText];
-  if (!match) {
-    return nil;
-  }
-
-  NSString* stringMatchingPattern = [text substringWithRange:match.range];
-
-  NSString* creditCardNumber =
-      [self substituteSimilarCharactersInRecognizedText:stringMatchingPattern];
-  NSCharacterSet* allowedCharacterSet =
-      [NSCharacterSet decimalDigitCharacterSet];
-  NSCharacterSet* creditCardNumberSet =
-      [NSCharacterSet characterSetWithCharactersInString:creditCardNumber];
-  if ([allowedCharacterSet isSupersetOfSet:creditCardNumberSet]) {
-    return creditCardNumber;
-  }
-  return nil;
-}
-
-// Substitutes commonly misrecognized characters, for example: 'S' -> '5' or
-// 'l' -> '1'
-- (NSString*)substituteSimilarCharactersInRecognizedText:
-    (NSString*)recognizedText {
-  NSDictionary* misrecognisedAlphabets = @{
-    @"B" : @"8",
-    @"C" : @"0",
-    @"D" : @"0",
-    @"G" : @"9",
-    @"I" : @"1",
-    @"L" : @"1",
-    @"O" : @"0",
-    @"Q" : @"0",
-    @"S" : @"5",
-    @"T" : @"7",
-    @"U" : @"0",
-    @"Z" : @"7"
-  };
-
-  NSString* substitutedText =
-      [[NSString alloc] initWithString:recognizedText].uppercaseString;
-  for (NSString* alphabet in misrecognisedAlphabets) {
-    NSString* digit = misrecognisedAlphabets[alphabet];
-    substitutedText =
-        [substitutedText stringByReplacingOccurrencesOfString:alphabet
-                                                   withString:digit];
-  }
-  return substitutedText;
-}
-
 @end

ios/chrome/browser/ui/settings/credit_card_scanner/credit_card_scanner_mediator_util.h

@@ -12,6 +12,13 @@ namespace ios {
 // Extracts credit card expiration month and year from |text|.
 NSDateComponents* ExtractExpirationDateFromText(NSString* text);
 
+// Extracts credit card number from |string|.
+NSString* ExtractCreditCardNumber(NSString* string);
+
+// Substitutes commonly misrecognized characters, for example: 'S' -> '5' or
+// 'l' -> '1'
+NSString* SubstituteSimilarCharactersInRecognizedText(NSString* recognizedText);
+
 }  // namespace ios
 
 #endif  // IOS_CHROME_BROWSER_UI_SETTINGS_CREDIT_CARD_SCANNER_CREDIT_CARD_SCANNER_MEDIATOR_UTIL_H_

ios/chrome/browser/ui/settings/credit_card_scanner/credit_card_scanner_mediator_util.mm

@@ -25,4 +25,72 @@ NSDateComponents* ExtractExpirationDateFromText(NSString* text) {
   return nil;
 }
 
+NSString* ExtractCreditCardNumber(NSString* string) {
+  NSString* text = [[NSString alloc] initWithString:string];
+  // Strip whitespaces and symbols.
+  NSArray* ignoreSymbols = @[ @" ", @"/", @"-", @".", @":", @"\\" ];
+  for (NSString* symbol in ignoreSymbols) {
+    text = [text stringByReplacingOccurrencesOfString:symbol withString:@""];
+  }
+
+  // Matches strings which have 13-19 characters between the start(^) and the
+  // end($) of the line.
+  NSString* pattern = @"^(\\w{13,19})$";
+
+  NSError* error;
+  NSRegularExpression* regex = [[NSRegularExpression alloc]
+      initWithPattern:pattern
+              options:NSRegularExpressionAllowCommentsAndWhitespace
+                error:&error];
+
+  NSRange rangeOfText = NSMakeRange(0, [text length]);
+  NSTextCheckingResult* match = [regex firstMatchInString:text
+                                                  options:0
+                                                    range:rangeOfText];
+  if (!match) {
+    return nil;
+  }
+
+  NSString* stringMatchingPattern = [text substringWithRange:match.range];
+
+  NSString* creditCardNumber =
+      SubstituteSimilarCharactersInRecognizedText(stringMatchingPattern);
+  NSCharacterSet* allowedCharacterSet =
+      [NSCharacterSet decimalDigitCharacterSet];
+  NSCharacterSet* creditCardNumberSet =
+      [NSCharacterSet characterSetWithCharactersInString:creditCardNumber];
+  if ([allowedCharacterSet isSupersetOfSet:creditCardNumberSet]) {
+    return creditCardNumber;
+  }
+  return nil;
+}
+
+NSString* SubstituteSimilarCharactersInRecognizedText(
+    NSString* recognizedText) {
+  NSDictionary* misrecognisedAlphabets = @{
+    @"B" : @"8",
+    @"C" : @"0",
+    @"D" : @"0",
+    @"G" : @"9",
+    @"I" : @"1",
+    @"L" : @"1",
+    @"O" : @"0",
+    @"Q" : @"0",
+    @"S" : @"5",
+    @"T" : @"7",
+    @"U" : @"0",
+    @"Z" : @"7"
+  };
+
+  NSString* substitutedText =
+      [[NSString alloc] initWithString:recognizedText].uppercaseString;
+  for (NSString* alphabet in misrecognisedAlphabets) {
+    NSString* digit = misrecognisedAlphabets[alphabet];
+    substitutedText =
+        [substitutedText stringByReplacingOccurrencesOfString:alphabet
+                                                   withString:digit];
+  }
+  return substitutedText;
+}
+
 }  // namespace ios

ios/chrome/browser/ui/settings/credit_card_scanner/credit_card_scanner_mediator_util_unittest.mm

@@ -4,6 +4,7 @@
 
 #import "ios/chrome/browser/ui/settings/credit_card_scanner/credit_card_scanner_mediator_util.h"
 
+#include "testing/gtest_mac.h"
 #include "testing/platform_test.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -12,6 +13,8 @@
 
 using CreditCardScannerMediatorUtilTest = PlatformTest;
 
+#pragma mark - Test ExtractExpirationDateFromText
+
 // Tests extracting month and year from valid date text.
 TEST_F(CreditCardScannerMediatorUtilTest,
        TestExtractExpirationDateFromValidDateText) {
@@ -44,3 +47,84 @@ TEST_F(CreditCardScannerMediatorUtilTest,
 
   EXPECT_FALSE(components);
 }
+
+#pragma mark - Test ExtractCreditCardNumber
+
+// Tests extracting card number from valid card number text (16 digits).
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromValidCreditCardNumber16Digits) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"4111111111111111");
+
+  EXPECT_NSEQ(cardNumber, @"4111111111111111");
+}
+
+// Tests extracting card number from valid card number text (14 digits).
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromValidCreditCardNumber14Digits) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"4111111111111");
+
+  EXPECT_NSEQ(cardNumber, @"4111111111111");
+}
+
+// Tests extracting card number from valid card number text contains wrong
+// characters.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromValidCreditCardNumberWithWrongCharacters) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"41/11-1111 1111.11:11");
+
+  EXPECT_NSEQ(cardNumber, @"4111111111111111");
+}
+
+// Tests extracting card number from text after converting
+// illegal characters.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromValidCreditCardNumberAfterConversion) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"41b1C1g1D1i1L1z1");
+
+  EXPECT_NSEQ(cardNumber, @"4181019101111171");
+}
+
+// Tests extracting card number from invalid card number text (10 digits).
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromInvalidCreditCardNumber10Digits) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"4111111111");
+
+  EXPECT_FALSE(cardNumber);
+}
+
+// Tests extracting card number from invalid card number text.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestExtractCardNumberFromInvalidCreditCardNumber) {
+  NSString* cardNumber = ios::ExtractCreditCardNumber(@"4111a11b11c11");
+
+  EXPECT_FALSE(cardNumber);
+}
+
+#pragma mark - Test SubstituteSimilarCharactersInRecognizedText
+
+// Tests substituting convertible characters with digits.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestSubstitutingTrueCharactersWithDigits) {
+  NSString* number =
+      ios::SubstituteSimilarCharactersInRecognizedText(@"bCdGiLoQsTuZ");
+
+  EXPECT_NSEQ(number, @"800911005707");
+}
+
+// Tests substituting text without characters with digits.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestSubstitutingTextWithoutCharacters) {
+  NSString* number =
+      ios::SubstituteSimilarCharactersInRecognizedText(@"4111111111111111");
+
+  EXPECT_NSEQ(number, @"4111111111111111");
+}
+
+// Tests substituting inconvertible characters with digits.
+TEST_F(CreditCardScannerMediatorUtilTest,
+       TestSubstitutingFalseCharactersWithDigits) {
+  NSString* cardNumber =
+      ios::SubstituteSimilarCharactersInRecognizedText(@"abcdefghi");
+
+  EXPECT_NSEQ(cardNumber, @"A800EF9H1");
+}