fix import pattern (#1604)

* fix import pattern

* fix style

* move check into cpplint.py

* replace than with rather than

Author: zxu123

Firestore/Example/Tests/Local/FSTLevelDBLRUGarbageCollectorTests.mm

@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-#import <Firestore/Source/Local/FSTLevelDB.h>
 #import "Firestore/Example/Tests/Local/FSTLRUGarbageCollectorTests.h"
 #import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
+#import "Firestore/Source/Local/FSTLevelDB.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -31,4 +31,4 @@ @implementation FSTLevelDBLRUGarbageCollectorTests
 
 @end
 
-NS_ASSUME_NONNULL_END
+NS_ASSUME_NONNULL_END

scripts/cpplint.py

@@ -4529,6 +4529,13 @@ def CheckIncludeLine(filename, clean_lines, linenum, include_state, error):
             '<%s> should be #include "%s" or #import <%s>' %
             (match.group(1), match.group(1), match.group(1)))
 
+  # framework-style imports should not be used for project imports
+  match = Match(r'#import\s*<(Firestore/Source/[^>]+)', line)
+  if match:
+    error(filenamne, linenum, 'build/include', 4,
+          'Prefer #import "%s" for project import rather than #import <>' %
+          match.group(1))
+
   # C++ system files should not be #imported
   match = Match(r'#import\s*<([^/>.]+)>', line)
   if match: