Check bookland code in ISBN

arthurdejong · arthurdejong · commit a71a1acedaa8 · 2017-08-30T22:32:17.000+02:00
This ensures that an InvalidComponent() exception is raised when an
unknown EAN bookland code is found. It will also raise this exception
when using to_isbn10() when not using the 978 code.
diff --git a/stdnum/isbn.py b/stdnum/isbn.py
@@ -100,6 +100,8 @@ def validate(number, convert=False):
             raise InvalidChecksum()
     elif len(number) == 13:
         ean.validate(number)
+        if number[:3] not in ('978', '979'):
+            raise InvalidComponent()
     else:
         raise InvalidLength()
     if convert:
@@ -159,7 +161,7 @@ def to_isbn10(number):
     elif isbn_type(min_number) != 'ISBN13':
         raise InvalidFormat('Not a valid ISBN13.')
     elif not number.startswith('978'):
-        raise InvalidFormat('Does not use 978 Bookland prefix.')
+        raise InvalidComponent('Does not use 978 Bookland prefix.')
     # strip EAN prefix
     number = number[3:-1].strip().strip('-')
     digit = _calc_isbn10_check_digit(min_number[3:-1])
diff --git a/tests/test_isbn.doctest b/tests/test_isbn.doctest
@@ -25,7 +25,7 @@ really useful as module documentation.
 >>> from stdnum import isbn
 
 
-Tests for mangling and incorect check digits.
+Tests for mangling and incorrect check digits.
 
 >>> isbn.validate('08515x-629-2')  # added X in the middle
 Traceback (most recent call last):
@@ -43,6 +43,10 @@ InvalidFormat: ...
 Traceback (most recent call last):
     ...
 InvalidLength: ...
+>>> isbn.validate('7501031311309')  # valid EAN, unknown bookland code
+Traceback (most recent call last):
+    ...
+InvalidComponent: ...
 
 
 See if ISBN10 to 13 conversion works.
@@ -88,7 +92,7 @@ InvalidFormat: ...
 >>> isbn.to_isbn10('9791843123391')
 Traceback (most recent call last):
     ...
-InvalidFormat: ...
+InvalidComponent: ...
 
 
 Regrouping tests.
@@ -99,7 +103,7 @@ Regrouping tests.
 ('', '99996', '', '7827', '0')
 >>> isbn.split('979-20-1234567-8')
 ('979', '', '', '201234567', '8')
->>> isbn.split('5413170121522')  # valid checkdigit, unknown prefix
+>>> isbn.split('5413170121522')  # valid check digit, unknown prefix
 ('', '', '', '541317012152', '2')
 
 
