OCT-1861: Cover /recalculate with API Tests (#394)

## Description

## Definition of Done

1. [ ] Acceptance criteria are met.
2. [ ] PR is manually tested before the merge by developer(s).
    - [ ] Happy path is manually checked.
3. [ ] PR is manually tested by QA when their assistance is required
(1).
- [ ] Octant Areas & Test Cases are checked for impact and updated if
required (2).
4. [ ] Unit tests are added unless there is a reason to omit them.
5. [ ] Automated tests are added when required.
6. [ ] The code is merged.
7. [ ] Tech documentation is added / updated, reviewed and approved
(including mandatory approval by a code owner, should such exist for
changed files).
    - [ ] BE: Swagger documentation is updated.
8. [ ] When required by QA:
    - [ ] Deployed to the relevant environment.
    - [ ] Passed system tests.

---

(1) Developer(s) in coordination with QA decide whether it's required.
For small tickets introducing small changes QA assistance is most
probably not required.

(2) [Octant Areas & Test
Cases](https://docs.google.com/spreadsheets/d/1cRe6dxuKJV3a4ZskAwWEPvrFkQm6rEfyUCYwLTYw_Cc).

backend/tests/api-e2e/test_api_delegation.py

@@ -57,6 +57,66 @@ def test_delegation(client: Client, payload: ScoreDelegationPayload):
     assert delegatee_score["status"] == "Known"
     assert float(delegatee_score["score"]) == float(delegator_score["score"])
 
+    # check if the secondary address is actually used off
+    resp, code = client.delegate(
+        primary_address=payload.primary_addr,
+        secondary_address=payload.secondary_addr,
+        primary_address_signature=payload.primary_addr_signature,
+        secondary_address_signature=payload.secondary_addr_signature,
+    )
+
+    assert code == 400
+    assert resp["message"] == "Delegation already exists"
+
+
+@pytest.mark.api
+def test_recalculate_in_delegation(client: Client, payload: ScoreDelegationPayload):
+    """
+    Recalculation can actually return two different results:
+    - if the delegation does not exist, it will return 400
+    - if the delegation exists, i.e. secondary address exists in the database, it will return 400
+    it's due to the fact that the recalculation is already stoned for a secondary address in our implementation
+    """
+    client.move_to_next_epoch(STARTING_EPOCH + 1)
+    client.move_to_next_epoch(STARTING_EPOCH + 2)
+    client.move_to_next_epoch(STARTING_EPOCH + 3)
+
+    epoch_no = client.wait_for_sync(STARTING_EPOCH + 3)
+    app.logger.debug(f"indexed epoch: {epoch_no}")
+
+    database.user.add_user(USER1_ADDRESS)
+    database.user.add_user(USER2_ADDRESS)
+
+    # try to recalculate before delegation
+    data, status = client.delegation_recalculate(
+        primary_address=payload.primary_addr,
+        secondary_address=payload.secondary_addr,
+        primary_address_signature=payload.primary_addr_signature,
+        secondary_address_signature=payload.secondary_addr_signature,
+    )
+    assert data["message"] == "Delegation does not exists"
+    assert status == 400
+
+    # make a delegation
+    _, status = client.delegate(
+        primary_address=payload.primary_addr,
+        secondary_address=payload.secondary_addr,
+        primary_address_signature=payload.primary_addr_signature,
+        secondary_address_signature=payload.secondary_addr_signature,
+    )
+    assert status == 201
+
+    # recalculate after delegation
+    data, status = client.delegation_recalculate(
+        primary_address=payload.primary_addr,
+        secondary_address=payload.secondary_addr,
+        primary_address_signature=payload.primary_addr_signature,
+        secondary_address_signature=payload.secondary_addr_signature,
+    )
+
+    assert data["message"] == "Invalid recalculation request"
+    assert status == 400
+
 
 @pytest.mark.api
 def test_check_delegation(client: Client, payload: ScoreDelegationPayload):

backend/tests/conftest.py

@@ -957,6 +957,24 @@ def delegate(
         )
         return json.loads(rv.text), rv.status_code
 
+    def delegation_recalculate(
+        self,
+        primary_address: str,
+        secondary_address: str,
+        primary_address_signature: str,
+        secondary_address_signature: str,
+    ) -> tuple[dict, int]:
+        rv = self._flask_client.put(
+            "/delegation/recalculate",
+            json={
+                "primaryAddr": primary_address,
+                "secondaryAddr": secondary_address,
+                "primaryAddrSignature": primary_address_signature,
+                "secondaryAddrSignature": secondary_address_signature,
+            },
+        )
+        return json.loads(rv.text), rv.status_code
+
     @property
     def config(self):
         return self._flask_client.application.config