Fix import in module_api module and docs on the new check_event_for_spam signature (#12918)

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

2 files changed, 19 insertions, 20 deletions

diff --git a/docs/modules/spam_checker_callbacks.md b/docs/modules/spam_checker_callbacks.md
index 71f6f9f0ab..ad35e667ed 100644
--- a/docs/modules/spam_checker_callbacks.md
+++ b/docs/modules/spam_checker_callbacks.md
@@ -11,29 +11,28 @@ The available spam checker callbacks are:
 ### `check_event_for_spam`
 
 _First introduced in Synapse v1.37.0_
-_Signature extended to support Allow and Code in Synapse v1.60.0_
-_Boolean and string return value types deprecated in Synapse v1.60.0_
+
+_Changed in Synapse v1.60.0: `synapse.module_api.NOT_SPAM` and `synapse.module_api.errors.Codes` can be returned by this callback. Returning a boolean or a string is now deprecated._ 
 
 ```python
-async def check_event_for_spam(event: "synapse.module_api.EventBase") -> Union["synapse.module_api.ALLOW", "synapse.module_api.error.Codes", str, bool]
+async def check_event_for_spam(event: "synapse.module_api.EventBase") -> Union["synapse.module_api.NOT_SPAM", "synapse.module_api.errors.Codes", str, bool]
 ```
 
-Called when receiving an event from a client or via federation. The callback must return either:
-  - `synapse.module_api.ALLOW`, to allow the operation. Other callbacks
-    may still decide to reject it.
-  - `synapse.api.Codes` to reject the operation with an error code. In case
-    of doubt, `synapse.api.error.Codes.FORBIDDEN` is a good error code.
-  - (deprecated) a `str` to reject the operation and specify an error message. Note that clients
+Called when receiving an event from a client or via federation. The callback must return one of:
+  - `synapse.module_api.NOT_SPAM`, to allow the operation. Other callbacks may still 
+    decide to reject it.
+  - `synapse.module_api.errors.Codes` to reject the operation with an error code. In case
+    of doubt, `synapse.module_api.errors.Codes.FORBIDDEN` is a good error code.
+  - (deprecated) a non-`Codes` `str` to reject the operation and specify an error message. Note that clients
     typically will not localize the error message to the user's preferred locale.
-  - (deprecated) on `False`, behave as `ALLOW`. Deprecated as confusing, as some
-    callbacks in expect `True` to allow and others `True` to reject.
-  - (deprecated) on `True`, behave as `synapse.api.error.Codes.FORBIDDEN`. Deprecated as confusing, as
-    some callbacks in expect `True` to allow and others `True` to reject.
+  - (deprecated) `False`, which is the same as returning `synapse.module_api.NOT_SPAM`.
+  - (deprecated) `True`, which is the same as returning `synapse.module_api.errors.Codes.FORBIDDEN`.
 
 If multiple modules implement this callback, they will be considered in order. If a
-callback returns `synapse.module_api.ALLOW`, Synapse falls through to the next one. The value of the
-first callback that does not return `synapse.module_api.ALLOW` will be used. If this happens, Synapse
-will not call any of the subsequent implementations of this callback.
+callback returns `synapse.module_api.NOT_SPAM`, Synapse falls through to the next one.
+The value of the first callback that does not return `synapse.module_api.NOT_SPAM` will
+be used. If this happens, Synapse will not call any of the subsequent implementations of
+this callback.
 
 ### `user_may_join_room`
 
diff --git a/docs/upgrade.md b/docs/upgrade.md
index e7eadadb64..e3c64da17f 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -177,11 +177,11 @@ has queries that can be used to check a database for this problem in advance.
 
 </details>
 
-## SpamChecker API's `check_event_for_spam` has a new signature.
+## New signature for the spam checker callback `check_event_for_spam`
 
 The previous signature has been deprecated.
 
-Whereas `check_event_for_spam` callbacks used to return `Union[str, bool]`, they should now return `Union["synapse.module_api.Allow", "synapse.module_api.errors.Codes"]`.
+Whereas `check_event_for_spam` callbacks used to return `Union[str, bool]`, they should now return `Union["synapse.module_api.NOT_SPAM", "synapse.module_api.errors.Codes"]`.
 
 This is part of an ongoing refactoring of the SpamChecker API to make it less ambiguous and more powerful.
 
@@ -204,8 +204,8 @@ async def check_event_for_spam(event):
         # Event is spam, mark it as forbidden (you may use some more precise error
         # code if it is useful).
         return synapse.module_api.errors.Codes.FORBIDDEN
-    # Event is not spam, mark it as `ALLOW`.
-    return synapse.module_api.ALLOW
+    # Event is not spam, mark it as such.
+    return synapse.module_api.NOT_SPAM
 ```
 
 # Upgrading to v1.59.0