[MRG+1] Add canonicalize_url function #65

tests/test_url.py

@@ -4,7 +4,10 @@
 import unittest
 from w3lib.url import (is_url, safe_url_string, safe_download_url,
     url_query_parameter, add_or_replace_parameter, url_query_cleaner,
-    file_uri_to_path, path_to_file_uri, any_to_uri, urljoin_rfc)
+    file_uri_to_path, path_to_file_uri, any_to_uri, urljoin_rfc,
+    canonicalize_url, parse_url)
+from six.moves.urllib.parse import urlparse
+
 
 class UrlTests(unittest.TestCase):
 
@@ -347,6 +350,209 @@ def test_urljoin_rfc_deprecated(self):
         self.assertEqual(jurl, b"http://www.example.com/test")
 
 
+class CanonicalizeUrlTest(unittest.TestCase):
+
+    def test_canonicalize_url(self):
+        # simplest case
+        self.assertEqual(canonicalize_url("http://www.example.com/"),
+                                          "http://www.example.com/")
+
+    def test_return_str(self):
+        assert isinstance(canonicalize_url(u"http://www.example.com"), str)
+        assert isinstance(canonicalize_url(b"http://www.example.com"), str)
+
+    def test_append_missing_path(self):
+        self.assertEqual(canonicalize_url("http://www.example.com"),
+                                          "http://www.example.com/")
+
+    def test_typical_usage(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/do?a=1&b=2&c=3"),
+                                          "http://www.example.com/do?a=1&b=2&c=3")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?c=1&b=2&a=3"),
+                                          "http://www.example.com/do?a=3&b=2&c=1")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?&a=1"),
+                                          "http://www.example.com/do?a=1")
+
+    def test_sorting(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/do?c=3&b=5&b=2&a=50"),
+                                          "http://www.example.com/do?a=50&b=2&b=5&c=3")
+
+    def test_keep_blank_values(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/do?b=&a=2", keep_blank_values=False),
+                                          "http://www.example.com/do?a=2")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?b=&a=2"),
+                                          "http://www.example.com/do?a=2&b=")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?b=&c&a=2", keep_blank_values=False),
+                                          "http://www.example.com/do?a=2")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?b=&c&a=2"),
+                                          "http://www.example.com/do?a=2&b=&c=")
+
+        self.assertEqual(canonicalize_url(u'http://www.example.com/do?1750,4'),
+                                           'http://www.example.com/do?1750%2C4=')
+
+    def test_spaces(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/do?q=a space&a=1"),
+                                          "http://www.example.com/do?a=1&q=a+space")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?q=a+space&a=1"),
+                                          "http://www.example.com/do?a=1&q=a+space")
+        self.assertEqual(canonicalize_url("http://www.example.com/do?q=a%20space&a=1"),
+                                          "http://www.example.com/do?a=1&q=a+space")
+
+    def test_canonicalize_url_unicode_path(self):
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé"),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9")
+
+    def test_canonicalize_url_unicode_query_string(self):
+        # default encoding for path and query is UTF-8
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé?q=résumé"),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?q=r%C3%A9sum%C3%A9")
+
+        # passed encoding will affect query string
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé?q=résumé", encoding='latin1'),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?q=r%E9sum%E9")
+
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé?country=Россия", encoding='cp1251'),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?country=%D0%EE%F1%F1%E8%FF")
+
+    def test_canonicalize_url_unicode_query_string_wrong_encoding(self):
+        # trying to encode with wrong encoding
+        # fallback to UTF-8
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé?currency=€", encoding='latin1'),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?currency=%E2%82%AC")
+
+        self.assertEqual(canonicalize_url(u"http://www.example.com/résumé?country=Россия", encoding='latin1'),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?country=%D0%A0%D0%BE%D1%81%D1%81%D0%B8%D1%8F")
+
+    def test_normalize_percent_encoding_in_paths(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/r%c3%a9sum%c3%a9"),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9")
+
+        # non-UTF8 encoded sequences: they should be kept untouched, only upper-cased
+        # 'latin1'-encoded sequence in path
+        self.assertEqual(canonicalize_url("http://www.example.com/a%a3do"),
+                                          "http://www.example.com/a%A3do")
+
+        # 'latin1'-encoded path, UTF-8 encoded query string
+        self.assertEqual(canonicalize_url("http://www.example.com/a%a3do?q=r%c3%a9sum%c3%a9"),
+                                          "http://www.example.com/a%A3do?q=r%C3%A9sum%C3%A9")
+
+        # 'latin1'-encoded path and query string
+        self.assertEqual(canonicalize_url("http://www.example.com/a%a3do?q=r%e9sum%e9"),
+                                          "http://www.example.com/a%A3do?q=r%E9sum%E9")
+
+    def test_normalize_percent_encoding_in_query_arguments(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/do?k=b%a3"),
+                                          "http://www.example.com/do?k=b%A3")
+
+        self.assertEqual(canonicalize_url("http://www.example.com/do?k=r%c3%a9sum%c3%a9"),
+                                          "http://www.example.com/do?k=r%C3%A9sum%C3%A9")
+
+    def test_non_ascii_percent_encoding_in_paths(self):
+        self.assertEqual(canonicalize_url("http://www.example.com/a do?a=1"),
+                                          "http://www.example.com/a%20do?a=1"),
+        self.assertEqual(canonicalize_url("http://www.example.com/a %20do?a=1"),
+                                          "http://www.example.com/a%20%20do?a=1"),
+        self.assertEqual(canonicalize_url(u"http://www.example.com/a do£.html?a=1"),
+                                          "http://www.example.com/a%20do%C2%A3.html?a=1")
+        self.assertEqual(canonicalize_url(b"http://www.example.com/a do\xc2\xa3.html?a=1"),
+                                          "http://www.example.com/a%20do%C2%A3.html?a=1")
+
+    def test_non_ascii_percent_encoding_in_query_arguments(self):
+        self.assertEqual(canonicalize_url(u"http://www.example.com/do?price=£500&a=5&z=3"),
+                                          u"http://www.example.com/do?a=5&price=%C2%A3500&z=3")
+        self.assertEqual(canonicalize_url(b"http://www.example.com/do?price=\xc2\xa3500&a=5&z=3"),
+                                          "http://www.example.com/do?a=5&price=%C2%A3500&z=3")
+        self.assertEqual(canonicalize_url(b"http://www.example.com/do?price(\xc2\xa3)=500&a=1"),
+                                          "http://www.example.com/do?a=1&price%28%C2%A3%29=500")
+
+    def test_urls_with_auth_and_ports(self):
+        self.assertEqual(canonicalize_url(u"http://user:pass@www.example.com:81/do?now=1"),
+                                          u"http://user:pass@www.example.com:81/do?now=1")
+
+    def test_remove_fragments(self):
+        self.assertEqual(canonicalize_url(u"http://user:pass@www.example.com/do?a=1#frag"),
+                                          u"http://user:pass@www.example.com/do?a=1")
+        self.assertEqual(canonicalize_url(u"http://user:pass@www.example.com/do?a=1#frag", keep_fragments=True),
+                                          u"http://user:pass@www.example.com/do?a=1#frag")
+
+    def test_dont_convert_safe_characters(self):
+        # dont convert safe characters to percent encoding representation
+        self.assertEqual(canonicalize_url(
+            "http://www.simplybedrooms.com/White-Bedroom-Furniture/Bedroom-Mirror:-Josephine-Cheval-Mirror.html"),
+            "http://www.simplybedrooms.com/White-Bedroom-Furniture/Bedroom-Mirror:-Josephine-Cheval-Mirror.html")
+
+    def test_safe_characters_unicode(self):
+        # urllib.quote uses a mapping cache of encoded characters. when parsing
+        # an already percent-encoded url, it will fail if that url was not
+        # percent-encoded as utf-8, that's why canonicalize_url must always
+        # convert the urls to string. the following test asserts that
+        # functionality.
+        self.assertEqual(canonicalize_url(u'http://www.example.com/caf%E9-con-leche.htm'),
+                                           'http://www.example.com/caf%E9-con-leche.htm')
+
+    def test_domains_are_case_insensitive(self):
+        self.assertEqual(canonicalize_url("http://www.EXAMPLE.com/"),
+                                          "http://www.example.com/")
+
+    def test_canonicalize_idns(self):
+        self.assertEqual(canonicalize_url(u'http://www.bücher.de?q=bücher'),
+                                           'http://www.xn--bcher-kva.de/?q=b%C3%BCcher')
+        # Japanese (+ reordering query parameters)
+        self.assertEqual(canonicalize_url(u'http://はじめよう.みんな/?query=サ&maxResults=5'),
+                                           'http://xn--p8j9a0d9c9a.xn--q9jyb4c/?maxResults=5&query=%E3%82%B5')
+
+    def test_quoted_slash_and_question_sign(self):
+        self.assertEqual(canonicalize_url("http://foo.com/AC%2FDC+rocks%3f/?yeah=1"),
+                         "http://foo.com/AC%2FDC+rocks%3F/?yeah=1")
+        self.assertEqual(canonicalize_url("http://foo.com/AC%2FDC/"),
+                         "http://foo.com/AC%2FDC/")
+
+    def test_canonicalize_urlparsed(self):
+        # canonicalize_url() can be passed an already urlparse'd URL
+        self.assertEqual(canonicalize_url(urlparse(u"http://www.example.com/résumé?q=résumé")),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?q=r%C3%A9sum%C3%A9")
+        self.assertEqual(canonicalize_url(urlparse('http://www.example.com/caf%e9-con-leche.htm')),
+                                          'http://www.example.com/caf%E9-con-leche.htm')
+        self.assertEqual(canonicalize_url(urlparse("http://www.example.com/a%a3do?q=r%c3%a9sum%c3%a9")),
+                                          "http://www.example.com/a%A3do?q=r%C3%A9sum%C3%A9")
+
+    def test_canonicalize_parse_url(self):
+        # parse_url() wraps urlparse and is used in link extractors
+        self.assertEqual(canonicalize_url(parse_url(u"http://www.example.com/résumé?q=résumé")),
+                                          "http://www.example.com/r%C3%A9sum%C3%A9?q=r%C3%A9sum%C3%A9")
+        self.assertEqual(canonicalize_url(parse_url('http://www.example.com/caf%e9-con-leche.htm')),
+                                          'http://www.example.com/caf%E9-con-leche.htm')
+        self.assertEqual(canonicalize_url(parse_url("http://www.example.com/a%a3do?q=r%c3%a9sum%c3%a9")),
+                                          "http://www.example.com/a%A3do?q=r%C3%A9sum%C3%A9")
+
+    def test_canonicalize_url_idempotence(self):
+        for url, enc in [(u'http://www.bücher.de/résumé?q=résumé', 'utf8'),
+                         (u'http://www.example.com/résumé?q=résumé', 'latin1'),
+                         (u'http://www.example.com/résumé?country=Россия', 'cp1251'),
+                         (u'http://はじめよう.みんな/?query=サ&maxResults=5', 'iso2022jp')]:
+            canonicalized = canonicalize_url(url, encoding=enc)
+
+            # if we canonicalize again, we ge the same result
+            self.assertEqual(canonicalize_url(canonicalized, encoding=enc), canonicalized)
+
+            # without encoding, already canonicalized URL is canonicalized identically
+            self.assertEqual(canonicalize_url(canonicalized), canonicalized)
+
+    def test_canonicalize_url_idna_exceptions(self):
+        # missing DNS label
+        self.assertEqual(
+            canonicalize_url(u"http://.example.com/résumé?q=résumé"),
+            "http://.example.com/r%C3%A9sum%C3%A9?q=r%C3%A9sum%C3%A9")
+
+        # DNS label too long
+        self.assertEqual(
+            canonicalize_url(
+                u"http://www.{label}.com/résumé?q=résumé".format(
+                    label=u"example"*11)),
+            "http://www.{label}.com/r%C3%A9sum%C3%A9?q=r%C3%A9sum%C3%A9".format(
+                    label=u"example"*11))
+
+
 if __name__ == "__main__":
     unittest.main()