settings: Add new setting for controlling who can move msgs to stream.

This commit adds a new setting 'move_messages_between_streams_policy`
for controlling who can move messages from one stream to other.

templates/zerver/api/changelog.md

@@ -10,6 +10,12 @@ below features are supported.
 
 ## Changes in Zulip 4.0
 
+**Feature level 56**
+
+* [`POST /register`](/api/register-queue): Added a new setting
+  `move_messages_between_streams_policy` for controlling who can
+  move messages between streams.
+
 **Feature level 55**
 
 * [`POST /register`](/api/register-queue): Added `realm_giphy_rating`

version.py

@@ -30,7 +30,7 @@ DESKTOP_WARNING_VERSION = "5.2.0"
 #
 # Changes should be accompanied by documentation explaining what the
 # new level means in templates/zerver/api/changelog.md.
-API_FEATURE_LEVEL = 55
+API_FEATURE_LEVEL = 56
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump

zerver/migrations/0320_realm_move_messages_between_streams_policy.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.1.7 on 2021-04-09 14:37
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("zerver", "0319_realm_giphy_rating"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="realm",
+            name="move_messages_between_streams_policy",
+            field=models.PositiveSmallIntegerField(default=2),
+        ),
+    ]

zerver/models.py

@@ -272,6 +272,11 @@ class Realm(models.Model):
     # Who in the organization is allowed to invite other users to streams.
     invite_to_stream_policy: int = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
 
+    # Who in the organization is allowed to move messages between streams.
+    move_messages_between_streams_policy: int = models.PositiveSmallIntegerField(
+        default=POLICY_ADMINS_ONLY
+    )
+
     USER_GROUP_EDIT_POLICY_MEMBERS = 1
     USER_GROUP_EDIT_POLICY_ADMINS = 2
     user_group_edit_policy: int = models.PositiveSmallIntegerField(
@@ -492,6 +497,7 @@ class Realm(models.Model):
         bot_creation_policy=int,
         create_stream_policy=int,
         invite_to_stream_policy=int,
+        move_messages_between_streams_policy=int,
         default_language=str,
         default_twenty_four_hour_time=bool,
         description=str,

zerver/openapi/zulip.yaml

@@ -3024,6 +3024,17 @@ paths:
                                       description: |
                                         The policy for which users can add other users to streams in this
                                         organization.
+                                    move_messages_between_streams_policy:
+                                      type: integer
+                                      description: |
+                                        The policy for which users can move messages from one stream to another.
+
+                                        * 1 = Members only
+                                        * 2 = Administrators only
+                                        * 3 = Full members only
+                                        * 4 = Moderators only
+
+                                        **Changes**: New in Zulip 4.0 (feature level 56)
                                     wildcard_mention_policy:
                                       type: integer
                                       description: |
@@ -7960,6 +7971,19 @@ paths:
 
                           **Changes**: New in Zulip 4.0 (feature level 50) replacing the
                           previous `realm_invite_by_admins_only` boolean.
+                      realm_move_messages_between_streams_policy:
+                        type: integer
+                        description: |
+                          Present if `realm` is present in `fetch_event_types`.
+
+                          The policy for which users can move messages from one stream to another.
+
+                          * 1 = Members only
+                          * 2 = Administrators only
+                          * 3 = Full members only
+                          * 4 = Moderators only
+
+                          **Changes**: New in Zulip 4.0 (feature level 56)
                       realm_inline_image_preview:
                         type: boolean
                         description: |

zerver/tests/test_events.py

@@ -1899,6 +1899,7 @@ class RealmPropertyActionTest(BaseAction):
             default_code_block_language=["python", "javascript"],
             message_content_delete_limit_seconds=[1000, 1100, 1200],
             invite_to_realm_policy=[4, 3, 2, 1],
+            move_messages_between_streams_policy=[4, 3, 2, 1],
         )
 
         vals = test_values.get(name)

zerver/tests/test_home.py

@@ -177,6 +177,7 @@ class HomeTest(ZulipTestCase):
         "realm_message_content_delete_limit_seconds",
         "realm_message_content_edit_limit_seconds",
         "realm_message_retention_days",
+        "realm_move_messages_between_streams_policy",
         "realm_name",
         "realm_name_changes_disabled",
         "realm_name_in_notifications",

zerver/tests/test_realm.py

@@ -563,6 +563,20 @@ class RealmTest(ZulipTestCase):
         result = self.client_patch("/json/realm", req)
         self.assert_json_error(result, "Invalid invite_to_realm_policy")
 
+    def test_change_move_messages_between_streams_policy(self) -> None:
+        # We need an admin user.
+        self.login("iago")
+        req = dict(
+            move_messages_between_streams_policy=orjson.dumps(Realm.POLICY_ADMINS_ONLY).decode()
+        )
+        result = self.client_patch("/json/realm", req)
+        self.assert_json_success(result)
+
+        invalid_value = 10
+        req = dict(move_messages_between_streams_policy=orjson.dumps(invalid_value).decode())
+        result = self.client_patch("/json/realm", req)
+        self.assert_json_error(result, "Invalid move_messages_between_streams_policy")
+
     def test_user_group_edit_policy(self) -> None:
         # We need an admin user.
         self.login("iago")
@@ -624,6 +638,7 @@ class RealmTest(ZulipTestCase):
             message_content_delete_limit_seconds=-10,
             wildcard_mention_policy=10,
             invite_to_realm_policy=10,
+            move_messages_between_streams_policy=10,
         )
 
         # We need an admin user.
@@ -902,6 +917,12 @@ class RealmAPITest(ZulipTestCase):
                 Realm.POLICY_FULL_MEMBERS_ONLY,
                 Realm.POLICY_MODERATORS_ONLY,
             ],
+            move_messages_between_streams_policy=[
+                Realm.POLICY_ADMINS_ONLY,
+                Realm.POLICY_MEMBERS_ONLY,
+                Realm.POLICY_FULL_MEMBERS_ONLY,
+                Realm.POLICY_MODERATORS_ONLY,
+            ],
         )
 
         vals = test_values.get(name)

zerver/views/realm.py

@@ -96,6 +96,9 @@ def update_realm(
     invite_to_stream_policy: Optional[int] = REQ(
         json_validator=check_int_in(Realm.COMMON_POLICY_TYPES), default=None
     ),
+    move_messages_between_streams_policy: Optional[int] = REQ(
+        json_validator=check_int_in(Realm.COMMON_POLICY_TYPES), default=None
+    ),
     user_group_edit_policy: Optional[int] = REQ(
         json_validator=check_int_in(Realm.USER_GROUP_EDIT_POLICY_TYPES), default=None
     ),