Implement correct logic for URLPatternSet set operators.

extensions/common/url_pattern_set_unittest.cc

Index: extensions/common/url_pattern_set_unittest.cc
diff --git a/extensions/common/url_pattern_set_unittest.cc b/extensions/common/url_pattern_set_unittest.cc
index 89b5435b820dc1fd0937c44c896fe6bda670b0d2..e0b0340090f40581a78ef4856efc316f265ec89f 100644
--- a/extensions/common/url_pattern_set_unittest.cc
+++ b/extensions/common/url_pattern_set_unittest.cc
@@ -17,6 +17,12 @@ void AddPattern(URLPatternSet* set, const std::string& pattern) {
   set->AddPattern(URLPattern(schemes, pattern));
 }
 
+void AddMatchAllURLsPattern(URLPatternSet* set) {
+  URLPattern pattern;
+  pattern.SetMatchAllURLs(true);
+  set->AddPattern(pattern);
+}
+
 URLPatternSet Patterns(const std::string& pattern) {
   URLPatternSet set;
   AddPattern(&set, pattern);
@@ -393,4 +399,58 @@ TEST(URLPatternSetTest, NwayUnion) {
   }
 }
 
+TEST(URLPatternSetTest, SubsetSpecialCases) {
+  URLPatternSet empty;
+  URLPatternSet all_urls;
+  AddMatchAllURLsPattern(&all_urls);

[not at google - send to devlin, 2014/02/27 21:10:46]

presumably these sets are copyable. so you could have
URLPatternSet all_urls = GetAllURLsPattern();
then change AddMatchAllURLsPattern.

+  URLPatternSet specific;
+  AddPattern(&specific, "http://www.google.com/*");
+  AddPattern(&specific, "http://www.yahoo.com/*");
+

[not at google - send to devlin, 2014/02/27 21:10:46]

there are some other cases here that it might be good to test, like overlapping
sets, having "*://www.google.com" and "http://*.google.com" in different/same
sets, etc. you might consider breaking up into separate test cases if that makes
it any easier, not sure about that.

+  {
+    URLPatternSet result;
+    result.AddPatterns(specific);
+    EXPECT_EQ(specific, result);
+    result.AddPatterns(all_urls);
+    EXPECT_EQ(all_urls, result);
+  }
+  {
+    URLPatternSet result;
+    result.AddPatterns(all_urls);
+    EXPECT_EQ(all_urls, result);
+    result.AddPatterns(specific);
+    EXPECT_EQ(all_urls, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateUnion(all_urls, specific, &result);
+    EXPECT_EQ(all_urls, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateUnion(specific, all_urls, &result);
+    EXPECT_EQ(all_urls, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateIntersection(all_urls, specific, &result);
+    EXPECT_EQ(specific, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateIntersection(specific, all_urls, &result);
+    EXPECT_EQ(specific, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateDifference(all_urls, specific, &result);
+    EXPECT_EQ(all_urls, result);
+  }
+  {
+    URLPatternSet result;
+    URLPatternSet::CreateDifference(specific, all_urls, &result);
+    EXPECT_EQ(empty, result);
+  }
+}
+
 }  // namespace extensions