Force order of Delete() -> Create() -> Update() in Cloudflare provider

Addresses issues with changing between A, AAAA and CNAME records in
both directions with the Cloudflare API

See also: github/octodns#507
See also: github/octodns#586
See also: github/octodns#587

octodns/provider/cloudflare.py

@@ -143,6 +143,11 @@ class CloudflareProvider(BaseProvider):
         resp.raise_for_status()
         return resp.json()
 
+    def _change_keyer(self, change):
+        key = change.__class__.__name__
+        order = {'Delete': 0, 'Create': 1, 'Update': 2}
+        return order[key]
+
     @property
     def zones(self):
         if self._zones is None:
@@ -660,6 +665,11 @@ class CloudflareProvider(BaseProvider):
             self.zones[name] = zone_id
             self._zone_records[name] = {}
 
+        # Force the operation order to be Delete() -> Create() -> Update()
+        # This will help avoid problems in updating a CNAME record into an
+        # A record and vice-versa
+        changes.sort(key=self._change_keyer)
+
         for change in changes:
             class_name = change.__class__.__name__
             getattr(self, '_apply_{}'.format(class_name))(change)

tests/test_octodns_provider_cloudflare.py

@@ -340,6 +340,10 @@ class TestCloudflareProvider(TestCase):
         self.assertTrue(plan.exists)
         # creates a the new value and then deletes all the old
         provider._request.assert_has_calls([
+            call('DELETE', '/zones/ff12ab34cd5611334422ab3322997650/'
+                 'dns_records/fc12ab34cd5611334422ab3322997653'),
+            call('DELETE', '/zones/ff12ab34cd5611334422ab3322997650/'
+                 'dns_records/fc12ab34cd5611334422ab3322997654'),
             call('PUT', '/zones/42/dns_records/'
                  'fc12ab34cd5611334422ab3322997655', data={
                      'content': '3.2.3.4',
@@ -347,11 +351,7 @@ class TestCloudflareProvider(TestCase):
                      'name': 'ttl.unit.tests',
                      'proxied': False,
                      'ttl': 300
-                 }),
-            call('DELETE', '/zones/ff12ab34cd5611334422ab3322997650/'
-                 'dns_records/fc12ab34cd5611334422ab3322997653'),
-            call('DELETE', '/zones/ff12ab34cd5611334422ab3322997650/'
-                 'dns_records/fc12ab34cd5611334422ab3322997654')
+                 })
         ])
 
     def test_update_add_swap(self):