Merge branch 'master' into #222-offensive-msg-autodeletion

13 files changed, 1141 insertions, 81 deletions

diff --git a/Pipfile b/Pipfile
index c7d0d766..f136a328 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,7 +4,7 @@ url = "https://pypi.org/simple"
 verify_ssl = true
 
 [packages]
-django = "~=2.2"
+django = "~=2.2.0"
 django-crispy-forms = "~=1.7.2"
 django-environ = "~=0.4.5"
 django-filter = "~=2.1.0"
@@ -26,8 +26,8 @@ django-allauth = "~=0.40"
 [dev-packages]
 coverage = "~=4.5.3"
 flake8 = "~=3.7"
-flake8-annotations = "~=1.0"
-flake8-bandit = "==1.0.2"
+flake8-annotations = "~=1.1"
+flake8-bandit = "~=2.1"
 flake8-bugbear = "~=19.8"
 flake8-docstrings = "~=1.4"
 flake8-import-order = "~=0.18"
diff --git a/Pipfile.lock b/Pipfile.lock
index 9a36c179..06b49ce7 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "d43e1ad137078dd4d79576380de6560c2935a38094b9c3d174fc232f0a50f4d4"
+            "sha256": "a4bfc709fcdecf5a3bd28326d51625c83a8a7661367cc69dbda20e3a55f1d9d3"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -171,6 +171,7 @@
         },
         "libsass": {
             "hashes": [
+                "sha256:175355d74bd040893d539154016153247ea9775d1655a36441c97a453887a0c0",
                 "sha256:3113ef32eaf3662c162c250db6883d7a5f177856bfd8bb632a147cb0a95e4fee",
                 "sha256:312d135e6bd1a137927fed781dab497c05930305265e3d3b1da3b3d916cd97a6",
                 "sha256:32f8322aad9b6b864b826adb5e193d704d5fb2c816f85a5cc5bf775730e5d024",
@@ -179,9 +180,11 @@
                 "sha256:607ce32c3b31542e0bf1bc2409627dd7247a3849ba720ec34d23426b96346199",
                 "sha256:6124594e72ba216b00131795ad5ea5de1e0cf8784e63a01e0c6a4e4c13fc7914",
                 "sha256:6129063002fc8337b734f5963ac3eb01ead51e9c88c6d27e73ddc9236cb15b2e",
+                "sha256:6d392ecd6e4de2ccfa3b1953f2da8461a2b7c8c8c17c24e1c335ab3040671c1a",
                 "sha256:75b38c236be6ca03e3dd3789f3044180fc0836b7c9e4991fcc52a8570f47dc91",
                 "sha256:9c711d4e4d003fec7f98fe87bb1faf7d88e6d648356413d8b8d9d76bd1844089",
                 "sha256:b15a0e61bd54764e658bc6931015453fa34d954f87c3b6fd35624e13bcacf69d",
+                "sha256:bc0c80a4e233b6b791a7f6f99415ab877e8a4d3a45085b68981c97d74dbfc8bf",
                 "sha256:c22cdc37121b730e5fb87bc8d3eee8c4b1fe219a04d198a535fbd22895c99e27",
                 "sha256:c5ba74babfb3a6976611312e0026c4668913cdf05e009921e1f54146ccdc02a4"
             ],
@@ -234,37 +237,39 @@
         },
         "psycopg2-binary": {
             "hashes": [
-                "sha256:080c72714784989474f97be9ab0ddf7b2ad2984527e77f2909fcd04d4df53809",
-                "sha256:110457be80b63ff4915febb06faa7be002b93a76e5ba19bf3f27636a2ef58598",
-                "sha256:171352a03b22fc099f15103959b52ee77d9a27e028895d7e5fde127aa8e3bac5",
-                "sha256:19d013e7b0817087517a4b3cab39c084d78898369e5c46258aab7be4f233d6a1",
-                "sha256:249b6b21ae4eb0f7b8423b330aa80fab5f821b9ffc3f7561a5e2fd6bb142cf5d",
-                "sha256:2ac0731d2d84b05c7bb39e85b7e123c3a0acd4cda631d8d542802c88deb9e87e",
-                "sha256:2b6d561193f0dc3f50acfb22dd52ea8c8dfbc64bcafe3938b5f209cc17cb6f00",
-                "sha256:2bd23e242e954214944481124755cbefe7c2cf563b1a54cd8d196d502f2578bf",
-                "sha256:3e1239242ca60b3725e65ab2f13765fc199b03af9eaf1b5572f0e97bdcee5b43",
-                "sha256:3eb70bb697abbe86b1d2b1316370c02ba320bfd1e9e35cf3b9566a855ea8e4e5",
-                "sha256:51a2fc7e94b98bd1bb5d4570936f24fc2b0541b63eccadf8fdea266db8ad2f70",
-                "sha256:52f1bdafdc764b7447e393ed39bb263eccb12bfda25a4ac06d82e3a9056251f6",
-                "sha256:5b3581319a3951f1e866f4f6c5e42023db0fae0284273b82e97dfd32c51985cd",
-                "sha256:63c1b66e3b2a3a336288e4bcec499e0dc310cd1dceaed1c46fa7419764c68877",
-                "sha256:8123a99f24ecee469e5c1339427bcdb2a33920a18bb5c0d58b7c13f3b0298ba3",
-                "sha256:85e699fcabe7f817c0f0a412d4e7c6627e00c412b418da7666ff353f38e30f67",
-                "sha256:8dbff4557bbef963697583366400822387cccf794ccb001f1f2307ed21854c68",
-                "sha256:908d21d08d6b81f1b7e056bbf40b2f77f8c499ab29e64ec5113052819ef1c89b",
-                "sha256:af39d0237b17d0a5a5f638e9dffb34013ce2b1d41441fd30283e42b22d16858a",
-                "sha256:af51bb9f055a3f4af0187149a8f60c9d516cf7d5565b3dac53358796a8fb2a5b",
-                "sha256:b2ecac57eb49e461e86c092761e6b8e1fd9654dbaaddf71a076dcc869f7014e2",
-                "sha256:cd37cc170678a4609becb26b53a2bc1edea65177be70c48dd7b39a1149cabd6e",
-                "sha256:d17e3054b17e1a6cb8c1140f76310f6ede811e75b7a9d461922d2c72973f583e",
-                "sha256:d305313c5a9695f40c46294d4315ed3a07c7d2b55e48a9010dad7db7a66c8b7f",
-                "sha256:dd0ef0eb1f7dd18a3f4187226e226a7284bda6af5671937a221766e6ef1ee88f",
-                "sha256:e1adff53b56db9905db48a972fb89370ad5736e0450b96f91bcf99cadd96cfd7",
-                "sha256:f0d43828003c82dbc9269de87aa449e9896077a71954fbbb10a614c017e65737",
-                "sha256:f78e8b487de4d92640105c1389e5b90be3496b1d75c90a666edd8737cc2dbab7"
+                "sha256:040234f8a4a8dfd692662a8308d78f63f31a97e1c42d2480e5e6810c48966a29",
+                "sha256:086f7e89ec85a6704db51f68f0dcae432eff9300809723a6e8782c41c2f48e03",
+                "sha256:18ca813fdb17bc1db73fe61b196b05dd1ca2165b884dd5ec5568877cabf9b039",
+                "sha256:19dc39616850342a2a6db70559af55b22955f86667b5f652f40c0e99253d9881",
+                "sha256:2166e770cb98f02ed5ee2b0b569d40db26788e0bf2ec3ae1a0d864ea6f1d8309",
+                "sha256:3a2522b1d9178575acee4adf8fd9f979f9c0449b00b4164bb63c3475ea6528ed",
+                "sha256:3aa773580f85a28ffdf6f862e59cb5a3cc7ef6885121f2de3fca8d6ada4dbf3b",
+                "sha256:3b5deaa3ee7180585a296af33e14c9b18c218d148e735c7accf78130765a47e3",
+                "sha256:407af6d7e46593415f216c7f56ba087a9a42bd6dc2ecb86028760aa45b802bd7",
+                "sha256:4c3c09fb674401f630626310bcaf6cd6285daf0d5e4c26d6e55ca26a2734e39b",
+                "sha256:4c6717962247445b4f9e21c962ea61d2e884fc17df5ddf5e35863b016f8a1f03",
+                "sha256:50446fae5681fc99f87e505d4e77c9407e683ab60c555ec302f9ac9bffa61103",
+                "sha256:5057669b6a66aa9ca118a2a860159f0ee3acf837eda937bdd2a64f3431361a2d",
+                "sha256:5dd90c5438b4f935c9d01fcbad3620253da89d19c1f5fca9158646407ed7df35",
+                "sha256:659c815b5b8e2a55193ede2795c1e2349b8011497310bb936da7d4745652823b",
+                "sha256:69b13fdf12878b10dc6003acc8d0abf3ad93e79813fd5f3812497c1c9fb9be49",
+                "sha256:7a1cb80e35e1ccea3e11a48afe65d38744a0e0bde88795cc56a4d05b6e4f9d70",
+                "sha256:7e6e3c52e6732c219c07bd97fff6c088f8df4dae3b79752ee3a817e6f32e177e",
+                "sha256:7f42a8490c4fe854325504ce7a6e4796b207960dabb2cbafe3c3959cb00d1d7e",
+                "sha256:84156313f258eafff716b2961644a4483a9be44a5d43551d554844d15d4d224e",
+                "sha256:8578d6b8192e4c805e85f187bc530d0f52ba86c39172e61cd51f68fddd648103",
+                "sha256:890167d5091279a27e2505ff0e1fb273f8c48c41d35c5b92adbf4af80e6b2ed6",
+                "sha256:9aadff9032e967865f9778485571e93908d27dab21d0fdfdec0ca779bb6f8ad9",
+                "sha256:9f24f383a298a0c0f9b3113b982e21751a8ecde6615494a3f1470eb4a9d70e9e",
+                "sha256:a73021b44813b5c84eda4a3af5826dd72356a900bac9bd9dd1f0f81ee1c22c2f",
+                "sha256:afd96845e12638d2c44d213d4810a08f4dc4a563f9a98204b7428e567014b1cd",
+                "sha256:b73ddf033d8cd4cc9dfed6324b1ad2a89ba52c410ef6877998422fcb9c23e3a8",
+                "sha256:dbc5cd56fff1a6152ca59445178652756f4e509f672e49ccdf3d79c1043113a4",
+                "sha256:eac8a3499754790187bb00574ab980df13e754777d346f85e0ff6df929bcd964",
+                "sha256:eaed1c65f461a959284649e37b5051224f4db6ebdc84e40b5e65f2986f101a08"
             ],
             "index": "pypi",
-            "version": "==2.8.3"
+            "version": "==2.8.4"
         },
         "pygments": {
             "hashes": [
@@ -283,10 +288,10 @@
         },
         "pytz": {
             "hashes": [
-                "sha256:26c0b32e437e54a18161324a2fca3c4b9846b74a8dccddd843113109e1116b32",
-                "sha256:c894d57500a4cd2d5c71114aaab77dbab5eabd9022308ce5ac9bb93a60a6f0c7"
+                "sha256:1c557d7d0e871de1f5ccd5833f60fb2550652da6be2693c1e02300743d21500d",
+                "sha256:b02c06db6cf09c12dd25137e563b31700d3b80fcc4ad23abb7a315f2789819be"
             ],
-            "version": "==2019.2"
+            "version": "==2019.3"
         },
         "pyuwsgi": {
             "hashes": [
@@ -414,10 +419,10 @@
         },
         "attrs": {
             "hashes": [
-                "sha256:ec20e7a4825331c1b5ebf261d111e16fa9612c1f7a5e1f884f12bd53a664dfd2",
-                "sha256:f913492e1663d3c36f502e5e9ba6cd13cf19d7fab50aa13239e420fef95e1396"
+                "sha256:08a96c641c3a74e44eb59afb61a24f2cb9f4d7188748e76ba4bb5edfa3cb7d1c",
+                "sha256:f7b7ce16570fe9965acd6d30101a28f62fb4a7f9e926b3bbc9b61f8b04247e72"
             ],
-            "version": "==19.2.0"
+            "version": "==19.3.0"
         },
         "bandit": {
             "hashes": [
@@ -496,11 +501,10 @@
         },
         "flake8-bandit": {
             "hashes": [
-                "sha256:a66c7b42af9530d5e988851ccee02958a51a85d46f1f4609ecc3546948f809b8",
-                "sha256:f7c3421fd9aebc63689c0693511e16dcad678fd4a0ce624b78ca91ae713eacdc"
+                "sha256:687fc8da2e4a239b206af2e54a90093572a60d0954f3054e23690739b0b0de3b"
             ],
             "index": "pypi",
-            "version": "==1.0.2"
+            "version": "==2.1.2"
         },
         "flake8-bugbear": {
             "hashes": [
@@ -705,20 +709,25 @@
         },
         "typed-ast": {
             "hashes": [
+                "sha256:1170afa46a3799e18b4c977777ce137bb53c7485379d9706af8a59f2ea1aa161",
                 "sha256:18511a0b3e7922276346bcb47e2ef9f38fb90fd31cb9223eed42c85d1312344e",
                 "sha256:262c247a82d005e43b5b7f69aff746370538e176131c32dda9cb0f324d27141e",
                 "sha256:2b907eb046d049bcd9892e3076c7a6456c93a25bebfe554e931620c90e6a25b0",
                 "sha256:354c16e5babd09f5cb0ee000d54cfa38401d8b8891eefa878ac772f827181a3c",
+                "sha256:48e5b1e71f25cfdef98b013263a88d7145879fbb2d5185f2a0c79fa7ebbeae47",
                 "sha256:4e0b70c6fc4d010f8107726af5fd37921b666f5b31d9331f0bd24ad9a088e631",
                 "sha256:630968c5cdee51a11c05a30453f8cd65e0cc1d2ad0d9192819df9978984529f4",
                 "sha256:66480f95b8167c9c5c5c87f32cf437d585937970f3fc24386f313a4c97b44e34",
                 "sha256:71211d26ffd12d63a83e079ff258ac9d56a1376a25bc80b1cdcdf601b855b90b",
+                "sha256:7954560051331d003b4e2b3eb822d9dd2e376fa4f6d98fee32f452f52dd6ebb2",
+                "sha256:838997f4310012cf2e1ad3803bce2f3402e9ffb71ded61b5ee22617b3a7f6b6e",
                 "sha256:95bd11af7eafc16e829af2d3df510cecfd4387f6453355188342c3e79a2ec87a",
                 "sha256:bc6c7d3fa1325a0c6613512a093bc2a2a15aeec350451cbdf9e1d4bffe3e3233",
                 "sha256:cc34a6f5b426748a507dd5d1de4c1978f2eb5626d51326e43280941206c209e1",
                 "sha256:d755f03c1e4a51e9b24d899561fec4ccaf51f210d52abdf8c07ee2849b212a36",
                 "sha256:d7c45933b1bdfaf9f36c579671fec15d25b06c8398f113dab64c18ed1adda01d",
                 "sha256:d896919306dd0aa22d0132f62a1b78d11aaf4c9fc5b3410d3c666b818191630a",
+                "sha256:fdc1c9bbf79510b76408840e009ed65958feba92a88833cdceecff93ae8fff66",
                 "sha256:ffde2fbfad571af120fcbfbbc61c72469e72f550d676c3342492a9dfdefb8f12"
             ],
             "version": "==1.4.0"
@@ -733,10 +742,10 @@
         },
         "virtualenv": {
             "hashes": [
-                "sha256:680af46846662bb38c5504b78bad9ed9e4f3ba2d54f54ba42494fdf94337fe30",
-                "sha256:f78d81b62d3147396ac33fc9d77579ddc42cc2a98dd9ea38886f616b33bc7fb2"
+                "sha256:3e3597e89c73df9313f5566e8fc582bd7037938d15b05329c232ec57a11a7ad5",
+                "sha256:5d370508bf32e522d79096e8cbea3499d47e624ac7e11e9089f9397a0b3318df"
             ],
-            "version": "==16.7.5"
+            "version": "==16.7.6"
         },
         "zipp": {
             "hashes": [
diff --git a/pydis_site/apps/api/migrations/0047_active_infractions_migration.py b/pydis_site/apps/api/migrations/0047_active_infractions_migration.py
new file mode 100644
index 00000000..9ac791dc
--- /dev/null
+++ b/pydis_site/apps/api/migrations/0047_active_infractions_migration.py
@@ -0,0 +1,105 @@
+# Generated by Django 2.2.6 on 2019-10-07 15:59
+
+from django.db import migrations
+from django.db.models import Count, Prefetch, QuerySet
+
+
+class ExpirationWrapper:
+    """Wraps an expiration date to properly compare permanent and temporary infractions."""
+
+    def __init__(self, infraction):
+        self.expiration_date = infraction.expires_at
+
+    def __lt__(self, other):
+        """An `expiration_date` is considered smaller when it comes earlier than the `other`."""
+        if self.expiration_date is None:
+            # A permanent infraction can never end sooner than another infraction
+            return False
+        elif other.expiration_date is None:
+            # If `self` is temporary, but `other` is permanent, `self` is smaller
+            return True
+        else:
+            return self.expiration_date < other.expiration_date
+
+    def __eq__(self, other):
+        """If both expiration dates are permanent they're equal, otherwise compare dates."""
+        if self.expiration_date is None and other.expiration_date is None:
+            return True
+        elif self.expiration_date is None or other.expiration_date is None:
+            return False
+        else:
+            return self.expiration_date == other.expiration_date
+
+
+def migrate_inactive_types_to_inactive(apps, schema_editor):
+    """Migrates infractions of non-active types to inactive."""
+    infraction_model = apps.get_model('api', 'Infraction')
+    infraction_model.objects.filter(type__in=('note', 'warning', 'kick')).update(active=False)
+
+
+def get_query(user_model, infraction_model, infr_type: str) -> QuerySet:
+    """
+    Creates QuerySet to fetch users with multiple active infractions of the given `type`.
+
+    The QuerySet will prefetch the infractions and attach them as an `.infractions` attribute to the
+    `User` instances.
+    """
+    active_infractions = infraction_model.objects.filter(type=infr_type, active=True)
+
+    # Build an SQL query by chaining methods together
+
+    # Get users with active infraction(s) of the provided `infr_type`
+    query = user_model.objects.filter(
+        infractions_received__type=infr_type, infractions_received__active=True
+    )
+
+    # Prefetch their active received infractions of `infr_type` and attach `.infractions` attribute
+    query = query.prefetch_related(
+        Prefetch('infractions_received', queryset=active_infractions, to_attr='infractions')
+    )
+
+    # Count and only include them if they have at least 2 active infractions of the `type`
+    query = query.annotate(num_infractions=Count('infractions_received'))
+    query = query.filter(num_infractions__gte=2)
+
+    # Make sure we return each individual only once
+    query = query.distinct()
+
+    return query
+
+
+def migrate_multiple_active_infractions_per_user_to_one(apps, schema_editor):
+    """
+    Make sure a user only has one active infraction of a given "active" infraction type.
+
+    If a user has multiple active infraction, we keep the one with longest expiration date active
+    and migrate the others to inactive.
+    """
+    infraction_model = apps.get_model('api', 'Infraction')
+    user_model = apps.get_model('api', 'User')
+
+    for infraction_type in ('ban', 'mute', 'superstar', 'watch'):
+        query = get_query(user_model, infraction_model, infraction_type)
+        for user in query:
+            infractions = sorted(user.infractions, key=ExpirationWrapper, reverse=True)
+            for infraction in infractions[1:]:
+                infraction.active = False
+                infraction.save()
+
+
+def reverse_migration(apps, schema_editor):
+    """There's no need to do anything special to reverse these migrations."""
+    return
+
+
+class Migration(migrations.Migration):
+    """Data migration to get the database consistent with the new infraction validation rules."""
+
+    dependencies = [
+        ('api', '0046_reminder_jump_url'),
+    ]
+
+    operations = [
+        migrations.RunPython(migrate_inactive_types_to_inactive, reverse_migration),
+        migrations.RunPython(migrate_multiple_active_infractions_per_user_to_one, reverse_migration)
+    ]
diff --git a/pydis_site/apps/api/migrations/0048_add_infractions_unique_constraints_active.py b/pydis_site/apps/api/migrations/0048_add_infractions_unique_constraints_active.py
new file mode 100644
index 00000000..4ea1fb90
--- /dev/null
+++ b/pydis_site/apps/api/migrations/0048_add_infractions_unique_constraints_active.py
@@ -0,0 +1,17 @@
+# Generated by Django 2.2.6 on 2019-10-07 18:27
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0047_active_infractions_migration'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='infraction',
+            constraint=models.UniqueConstraint(condition=models.Q(active=True), fields=('user', 'type'), name='unique_active_infraction_per_type_per_user'),
+        ),
+    ]
diff --git a/pydis_site/apps/api/models/bot/infraction.py b/pydis_site/apps/api/models/bot/infraction.py
index dfb32a97..108fd3a2 100644
--- a/pydis_site/apps/api/models/bot/infraction.py
+++ b/pydis_site/apps/api/models/bot/infraction.py
@@ -71,3 +71,10 @@ class Infraction(ModelReprMixin, models.Model):
         """Defines the meta options for the infraction model."""
 
         ordering = ['-inserted_at']
+        constraints = (
+            models.UniqueConstraint(
+                fields=["user", "type"],
+                condition=models.Q(active=True),
+                name="unique_active_infraction_per_type_per_user"
+            ),
+        )
diff --git a/pydis_site/apps/api/models/bot/user.py b/pydis_site/apps/api/models/bot/user.py
index 21617dc4..5140d2bf 100644
--- a/pydis_site/apps/api/models/bot/user.py
+++ b/pydis_site/apps/api/models/bot/user.py
@@ -50,7 +50,7 @@ class User(ModelReprMixin, models.Model):
 
     def __str__(self):
         """Returns the name and discriminator for the current user, for display purposes."""
-        return f"{self.name}#{self.discriminator}"
+        return f"{self.name}#{self.discriminator:0>4}"
 
     @property
     def top_role(self) -> Role:
diff --git a/pydis_site/apps/api/serializers.py b/pydis_site/apps/api/serializers.py
index bc94349e..52a82eac 100644
--- a/pydis_site/apps/api/serializers.py
+++ b/pydis_site/apps/api/serializers.py
@@ -1,6 +1,6 @@
 """Converters from Django models to data interchange formats and back."""
-
 from rest_framework.serializers import ModelSerializer, PrimaryKeyRelatedField, ValidationError
+from rest_framework.validators import UniqueTogetherValidator
 from rest_framework_bulk import BulkSerializerMixin
 
 from .models import (
@@ -106,11 +106,22 @@ class InfractionSerializer(ModelSerializer):
         fields = (
             'id', 'inserted_at', 'expires_at', 'active', 'user', 'actor', 'type', 'reason', 'hidden'
         )
+        validators = [
+            UniqueTogetherValidator(
+                queryset=Infraction.objects.filter(active=True),
+                fields=['user', 'type'],
+                message='This user already has an active infraction of this type.',
+            )
+        ]
 
     def validate(self, attrs: dict) -> dict:
         """Validate data constraints for the given data and abort if it is invalid."""
         infr_type = attrs.get('type')
 
+        active = attrs.get('active')
+        if active and infr_type in ('note', 'warning', 'kick'):
+            raise ValidationError({'active': [f'{infr_type} infractions cannot be active.']})
+
         expires_at = attrs.get('expires_at')
         if expires_at and infr_type in ('kick', 'warning'):
             raise ValidationError({'expires_at': [f'{infr_type} infractions cannot expire.']})
diff --git a/pydis_site/apps/api/tests/migrations/__init__.py b/pydis_site/apps/api/tests/migrations/__init__.py
new file mode 100644
index 00000000..38e42ffc
--- /dev/null
+++ b/pydis_site/apps/api/tests/migrations/__init__.py
@@ -0,0 +1 @@
+"""This submodule contains tests for functions used in data migrations."""
diff --git a/pydis_site/apps/api/tests/migrations/base.py b/pydis_site/apps/api/tests/migrations/base.py
new file mode 100644
index 00000000..0c0a5bd0
--- /dev/null
+++ b/pydis_site/apps/api/tests/migrations/base.py
@@ -0,0 +1,102 @@
+"""Includes utilities for testing migrations."""
+from django.db import connection
+from django.db.migrations.executor import MigrationExecutor
+from django.test import TestCase
+
+
+class MigrationsTestCase(TestCase):
+    """
+    A `TestCase` subclass to test migration files.
+
+    To be able to properly test a migration, we will need to inject data into the test database
+    before the migrations we want to test are applied, but after the older migrations have been
+    applied. This makes sure that we are testing "as if" we were actually applying this migration
+    to a database in the state it was in before introducing the new migration.
+
+    To set up a MigrationsTestCase, create a subclass of this class and set the following
+    class-level attributes:
+
+    - app: The name of the app that contains the migrations (e.g., `'api'`)
+    - migration_prior: The name* of the last migration file before the migrations you want to test
+    - migration_target: The name* of the last migration file we want to test
+
+    *) Specify the file names without a path or the `.py` file extension.
+
+    Additionally, overwrite the `setUpMigrationData` in the subclass to inject data into the
+    database before the migrations we want to test are applied. Please read the docstring of the
+    method for more information. An optional hook, `setUpPostMigrationData` is also provided.
+    """
+
+    # These class-level attributes should be set in classes that inherit from this base class.
+    app = None
+    migration_prior = None
+    migration_target = None
+
+    @classmethod
+    def setUpTestData(cls):
+        """
+        Injects data into the test database prior to the migration we're trying to test.
+
+        This class methods reverts the test database back to the state of the last migration file
+        prior to the migrations we want to test. It will then allow the user to inject data into the
+        test database by calling the `setUpMigrationData` hook. After the data has been injected, it
+        will apply the migrations we want to test and call the `setUpPostMigrationData` hook. The
+        user can now test if the migration correctly migrated the injected test data.
+        """
+        if not cls.app:
+            raise ValueError("The `app` attribute was not set.")
+
+        if not cls.migration_prior or not cls.migration_target:
+            raise ValueError("Both ` migration_prior` and `migration_target` need to be set.")
+
+        cls.migrate_from = [(cls.app, cls.migration_prior)]
+        cls.migrate_to = [(cls.app, cls.migration_target)]
+
+        # Reverse to database state prior to the migrations we want to test
+        executor = MigrationExecutor(connection)
+        executor.migrate(cls.migrate_from)
+
+        # Call the data injection hook with the current state of the project
+        old_apps = executor.loader.project_state(cls.migrate_from).apps
+        cls.setUpMigrationData(old_apps)
+
+        # Run the migrations we want to test
+        executor = MigrationExecutor(connection)
+        executor.loader.build_graph()
+        executor.migrate(cls.migrate_to)
+
+        # Save the project state so we're able to work with the correct model states
+        cls.apps = executor.loader.project_state(cls.migrate_to).apps
+
+        # Call `setUpPostMigrationData` to potentially set up post migration data used in testing
+        cls.setUpPostMigrationData(cls.apps)
+
+    @classmethod
+    def setUpMigrationData(cls, apps):
+        """
+        Override this method to inject data into the test database before the migration is applied.
+
+        This method will be called after setting up the database according to the migrations that
+        come before the migration(s) we are trying to test, but before the to-be-tested migration(s)
+        are applied. This allows us to simulate a database state just prior to the migrations we are
+        trying to test.
+
+        To make sure we're creating objects according to the state the models were in at this point
+        in the migration history, use `apps.get_model(app_name: str, model_name: str)` to get the
+        appropriate model, e.g.:
+
+        >>> Infraction = apps.get_model('api', 'Infraction')
+        """
+        pass
+
+    @classmethod
+    def setUpPostMigrationData(cls, apps):
+        """
+        Set up additional test data after the target migration has been applied.
+
+        Use `apps.get_model(app_name: str, model_name: str)` to get the correct instances of the
+        model classes:
+
+        >>> Infraction = apps.get_model('api', 'Infraction')
+        """
+        pass
diff --git a/pydis_site/apps/api/tests/migrations/test_active_infraction_migration.py b/pydis_site/apps/api/tests/migrations/test_active_infraction_migration.py
new file mode 100644
index 00000000..8dc29b34
--- /dev/null
+++ b/pydis_site/apps/api/tests/migrations/test_active_infraction_migration.py
@@ -0,0 +1,496 @@
+"""Tests for the data migration in `filename`."""
+import logging
+from collections import ChainMap, namedtuple
+from datetime import timedelta
+from itertools import count
+from typing import Dict, Iterable, Type, Union
+
+from django.db.models import Q
+from django.forms.models import model_to_dict
+from django.utils import timezone
+
+from pydis_site.apps.api.models import Infraction, User
+from .base import MigrationsTestCase
+
+log = logging.getLogger(__name__)
+log.setLevel(logging.DEBUG)
+
+
+InfractionHistory = namedtuple('InfractionHistory', ("user_id", "infraction_history"))
+
+
+class InfractionFactory:
+    """Factory that creates infractions for a User instance."""
+
+    infraction_id = count(1)
+    user_id = count(1)
+    default_values = {
+        'active': True,
+        'expires_at': None,
+        'hidden': False,
+    }
+
+    @classmethod
+    def create(
+        cls,
+        actor: User,
+        infractions: Iterable[Dict[str, Union[str, int, bool]]],
+        infraction_model: Type[Infraction] = Infraction,
+        user_model: Type[User] = User,
+    ) -> InfractionHistory:
+        """
+        Creates `infractions` for the `user` with the given `actor`.
+
+        The `infractions` dictionary can contain the following fields:
+         - `type` (required)
+         - `active` (default: True)
+         - `expires_at` (default: None; i.e, permanent)
+         - `hidden` (default: False).
+
+        The parameters `infraction_model` and `user_model` can be used to pass in an instance of
+        both model classes from a different migration/project state.
+        """
+        user_id = next(cls.user_id)
+        user = user_model.objects.create(
+            id=user_id,
+            name=f"Infracted user {user_id}",
+            discriminator=user_id,
+            avatar_hash=None,
+        )
+        infraction_history = []
+
+        for infraction in infractions:
+            infraction = dict(infraction)
+            infraction["id"] = next(cls.infraction_id)
+            infraction = ChainMap(infraction, cls.default_values)
+            new_infraction = infraction_model.objects.create(
+                user=user,
+                actor=actor,
+                type=infraction["type"],
+                reason=f"`{infraction['type']}` infraction (ID: {infraction['id']} of {user}",
+                active=infraction['active'],
+                hidden=infraction['hidden'],
+                expires_at=infraction['expires_at'],
+            )
+            infraction_history.append(new_infraction)
+
+        return InfractionHistory(user_id=user_id, infraction_history=infraction_history)
+
+
+class InfractionFactoryTests(MigrationsTestCase):
+    """Tests for the InfractionFactory."""
+
+    app = "api"
+    migration_prior = "0046_reminder_jump_url"
+    migration_target = "0046_reminder_jump_url"
+
+    @classmethod
+    def setUpPostMigrationData(cls, apps):
+        """Create a default actor for all infractions."""
+        cls.infraction_model = apps.get_model('api', 'Infraction')
+        cls.user_model = apps.get_model('api', 'User')
+
+        cls.actor = cls.user_model.objects.create(
+            id=9999,
+            name="Unknown Moderator",
+            discriminator=1040,
+            avatar_hash=None,
+        )
+
+    def test_infraction_factory_total_count(self):
+        """Does the test database hold as many infractions as we tried to create?"""
+        InfractionFactory.create(
+            actor=self.actor,
+            infractions=(
+                {'type': 'kick', 'active': False, 'hidden': False},
+                {'type': 'ban', 'active': True, 'hidden': False},
+                {'type': 'note', 'active': False, 'hidden': True},
+            ),
+            infraction_model=self.infraction_model,
+            user_model=self.user_model,
+        )
+        database_count = Infraction.objects.all().count()
+        self.assertEqual(3, database_count)
+
+    def test_infraction_factory_multiple_users(self):
+        """Does the test database hold as many infractions as we tried to create?"""
+        for _user in range(5):
+            InfractionFactory.create(
+                actor=self.actor,
+                infractions=(
+                    {'type': 'kick', 'active': False, 'hidden': True},
+                    {'type': 'ban', 'active': True, 'hidden': False},
+                ),
+                infraction_model=self.infraction_model,
+                user_model=self.user_model,
+            )
+
+        # Check if infractions and users are recorded properly in the database
+        database_count = Infraction.objects.all().count()
+        self.assertEqual(database_count, 10)
+
+        user_count = User.objects.all().count()
+        self.assertEqual(user_count, 5 + 1)
+
+    def test_infraction_factory_sets_correct_fields(self):
+        """Does the InfractionFactory set the correct attributes?"""
+        infractions = (
+            {
+                'type': 'note',
+                'active': False,
+                'hidden': True,
+                'expires_at': timezone.now()
+            },
+            {'type': 'warning', 'active': False, 'hidden': False, 'expires_at': None},
+            {'type': 'watch', 'active': False, 'hidden': True, 'expires_at': None},
+            {'type': 'mute', 'active': True, 'hidden': False, 'expires_at': None},
+            {'type': 'kick', 'active': True, 'hidden': True, 'expires_at': None},
+            {'type': 'ban', 'active': True, 'hidden': False, 'expires_at': None},
+            {
+                'type': 'superstar',
+                'active': True,
+                'hidden': True,
+                'expires_at': timezone.now()
+            },
+        )
+
+        InfractionFactory.create(
+            actor=self.actor,
+            infractions=infractions,
+            infraction_model=self.infraction_model,
+            user_model=self.user_model,
+        )
+
+        for infraction in infractions:
+            with self.subTest(**infraction):
+                self.assertTrue(Infraction.objects.filter(**infraction).exists())
+
+
+class ActiveInfractionMigrationTests(MigrationsTestCase):
+    """
+    Tests the active infraction data migration.
+
+    The active infraction data migration should do the following things:
+
+    1.  migrates all active notes, warnings, and kicks to an inactive status;
+    2.  migrates all users with multiple active infractions of a single type to have only one active
+        infraction of that type. The infraction with the longest duration stays active.
+    """
+
+    app = "api"
+    migration_prior = "0046_reminder_jump_url"
+    migration_target = "0047_active_infractions_migration"
+
+    @classmethod
+    def setUpMigrationData(cls, apps):
+        """Sets up an initial database state that contains the relevant test cases."""
+        # Fetch the Infraction and User model in the current migration state
+        cls.infraction_model = apps.get_model('api', 'Infraction')
+        cls.user_model = apps.get_model('api', 'User')
+
+        cls.created_infractions = {}
+
+        # Moderator that serves as actor for all infractions
+        cls.user_moderator = cls.user_model.objects.create(
+            id=9999,
+            name="Olivier de Vienne",
+            discriminator=1040,
+            avatar_hash=None,
+        )
+
+        # User #1: clean user with no infractions
+        cls.created_infractions["no infractions"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=[],
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #2: One inactive note infraction
+        cls.created_infractions["one inactive note"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'note', 'active': False, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #3: One active note infraction
+        cls.created_infractions["one active note"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'note', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #4: One active and one inactive note infraction
+        cls.created_infractions["one active and one inactive note"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'note', 'active': False, 'hidden': True},
+                {'type': 'note', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #5: Once active note, one active kick, once active warning
+        cls.created_infractions["active note, kick, warning"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'note', 'active': True, 'hidden': True},
+                {'type': 'kick', 'active': True, 'hidden': True},
+                {'type': 'warning', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #6: One inactive ban and one active ban
+        cls.created_infractions["one inactive and one active ban"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'ban', 'active': False, 'hidden': True},
+                {'type': 'ban', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #7: Two active permanent bans
+        cls.created_infractions["two active perm bans"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'ban', 'active': True, 'hidden': True},
+                {'type': 'ban', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #8: Multiple active temporary bans
+        cls.created_infractions["multiple active temp bans"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=1)
+                },
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=10)
+                },
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=20)
+                },
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=5)
+                },
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #9: One active permanent ban, two active temporary bans
+        cls.created_infractions["active perm, two active temp bans"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=10)
+                },
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': None,
+                },
+                {
+                    'type': 'ban',
+                    'active': True,
+                    'hidden': True,
+                    'expires_at': timezone.now() + timedelta(days=7)
+                },
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #10: One inactive permanent ban, two active temporary bans
+        cls.created_infractions["one inactive perm ban, two active temp bans"] = (
+            InfractionFactory.create(
+                actor=cls.user_moderator,
+                infractions=(
+                    {
+                        'type': 'ban',
+                        'active': True,
+                        'hidden': True,
+                        'expires_at': timezone.now() + timedelta(days=10)
+                    },
+                    {
+                        'type': 'ban',
+                        'active': False,
+                        'hidden': True,
+                        'expires_at': None,
+                    },
+                    {
+                        'type': 'ban',
+                        'active': True,
+                        'hidden': True,
+                        'expires_at': timezone.now() + timedelta(days=7)
+                    },
+                ),
+                infraction_model=cls.infraction_model,
+                user_model=cls.user_model,
+            )
+        )
+
+        # User #11: Active ban, active mute, active superstar
+        cls.created_infractions["active ban, mute, and superstar"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'ban', 'active': True, 'hidden': True},
+                {'type': 'mute', 'active': True, 'hidden': True},
+                {'type': 'superstar', 'active': True, 'hidden': True},
+                {'type': 'watch', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+        # User #12: Multiple active bans, active mutes, active superstars
+        cls.created_infractions["multiple active bans, mutes, stars"] = InfractionFactory.create(
+            actor=cls.user_moderator,
+            infractions=(
+                {'type': 'ban', 'active': True, 'hidden': True},
+                {'type': 'ban', 'active': True, 'hidden': True},
+                {'type': 'ban', 'active': True, 'hidden': True},
+                {'type': 'mute', 'active': True, 'hidden': True},
+                {'type': 'mute', 'active': True, 'hidden': True},
+                {'type': 'mute', 'active': True, 'hidden': True},
+                {'type': 'superstar', 'active': True, 'hidden': True},
+                {'type': 'superstar', 'active': True, 'hidden': True},
+                {'type': 'superstar', 'active': True, 'hidden': True},
+                {'type': 'watch', 'active': True, 'hidden': True},
+                {'type': 'watch', 'active': True, 'hidden': True},
+                {'type': 'watch', 'active': True, 'hidden': True},
+            ),
+            infraction_model=cls.infraction_model,
+            user_model=cls.user_model,
+        )
+
+    def test_all_never_active_types_became_inactive(self):
+        """Are all infractions of a non-active type inactive after the migration?"""
+        inactive_type_query = Q(type="note") | Q(type="warning") | Q(type="kick")
+        self.assertFalse(
+            self.infraction_model.objects.filter(inactive_type_query, active=True).exists()
+        )
+
+    def test_migration_left_clean_user_without_infractions(self):
+        """Do users without infractions have no infractions after the migration?"""
+        user_id, infraction_history = self.created_infractions["no infractions"]
+        self.assertFalse(
+            self.infraction_model.objects.filter(user__id=user_id).exists()
+        )
+
+    def test_migration_left_user_with_inactive_note_untouched(self):
+        """Did the migration leave users with only an inactive note untouched?"""
+        user_id, infraction_history = self.created_infractions["one inactive note"]
+        inactive_note = infraction_history[0]
+        self.assertTrue(
+            self.infraction_model.objects.filter(**model_to_dict(inactive_note)).exists()
+        )
+
+    def test_migration_only_touched_active_field_of_active_note(self):
+        """Does the migration only change the `active` field?"""
+        user_id, infraction_history = self.created_infractions["one active note"]
+        note = model_to_dict(infraction_history[0])
+        note['active'] = False
+        self.assertTrue(
+            self.infraction_model.objects.filter(**note).exists()
+        )
+
+    def test_migration_only_touched_active_field_of_active_note_left_inactive_untouched(self):
+        """Does the migration only change the `active` field of active notes?"""
+        user_id, infraction_history = self.created_infractions["one active and one inactive note"]
+        for note in infraction_history:
+            with self.subTest(active=note.active):
+                note = model_to_dict(note)
+                note['active'] = False
+                self.assertTrue(
+                    self.infraction_model.objects.filter(**note).exists()
+                )
+
+    def test_migration_migrates_all_nonactive_types_to_inactive(self):
+        """Do we set the `active` field of all non-active infractions to `False`?"""
+        user_id, infraction_history = self.created_infractions["active note, kick, warning"]
+        self.assertFalse(
+            self.infraction_model.objects.filter(user__id=user_id, active=True).exists()
+        )
+
+    def test_migration_leaves_user_with_one_active_ban_untouched(self):
+        """Do we leave a user with one active and one inactive ban untouched?"""
+        user_id, infraction_history = self.created_infractions["one inactive and one active ban"]
+        for infraction in infraction_history:
+            with self.subTest(active=infraction.active):
+                self.assertTrue(
+                    self.infraction_model.objects.filter(**model_to_dict(infraction)).exists()
+                )
+
+    def test_migration_turns_double_active_perm_ban_into_single_active_perm_ban(self):
+        """Does the migration turn two active permanent bans into one active permanent ban?"""
+        user_id, infraction_history = self.created_infractions["two active perm bans"]
+        active_count = self.infraction_model.objects.filter(user__id=user_id, active=True).count()
+        self.assertEqual(active_count, 1)
+
+    def test_migration_leaves_temporary_ban_with_longest_duration_active(self):
+        """Does the migration turn two active permanent bans into one active permanent ban?"""
+        user_id, infraction_history = self.created_infractions["multiple active temp bans"]
+        active_ban = self.infraction_model.objects.get(user__id=user_id, active=True)
+        self.assertEqual(active_ban.expires_at, infraction_history[2].expires_at)
+
+    def test_migration_leaves_permanent_ban_active(self):
+        """Does the migration leave the permanent ban active?"""
+        user_id, infraction_history = self.created_infractions["active perm, two active temp bans"]
+        active_ban = self.infraction_model.objects.get(user__id=user_id, active=True)
+        self.assertIsNone(active_ban.expires_at)
+
+    def test_migration_leaves_longest_temp_ban_active_with_inactive_permanent_ban(self):
+        """Does the longest temp ban stay active, even with an inactive perm ban present?"""
+        user_id, infraction_history = self.created_infractions[
+            "one inactive perm ban, two active temp bans"
+        ]
+        active_ban = self.infraction_model.objects.get(user__id=user_id, active=True)
+        self.assertEqual(active_ban.expires_at, infraction_history[0].expires_at)
+
+    def test_migration_leaves_all_active_types_active_if_one_of_each_exists(self):
+        """Do all active infractions stay active if only one of each is present?"""
+        user_id, infraction_history = self.created_infractions["active ban, mute, and superstar"]
+        active_count = self.infraction_model.objects.filter(user__id=user_id, active=True).count()
+        self.assertEqual(active_count, 4)
+
+    def test_migration_reduces_all_active_types_to_a_single_active_infraction(self):
+        """Do we reduce all of the infraction types to one active infraction?"""
+        user_id, infraction_history = self.created_infractions["multiple active bans, mutes, stars"]
+        active_infractions = self.infraction_model.objects.filter(user__id=user_id, active=True)
+        self.assertEqual(len(active_infractions), 4)
+        types_observed = [infraction.type for infraction in active_infractions]
+
+        for infraction_type in ('ban', 'mute', 'superstar', 'watch'):
+            with self.subTest(type=infraction_type):
+                self.assertIn(infraction_type, types_observed)
diff --git a/pydis_site/apps/api/tests/migrations/test_base.py b/pydis_site/apps/api/tests/migrations/test_base.py
new file mode 100644
index 00000000..f69bc92c
--- /dev/null
+++ b/pydis_site/apps/api/tests/migrations/test_base.py
@@ -0,0 +1,135 @@
+import logging
+from unittest.mock import call, patch
+
+from django.db.migrations.loader import MigrationLoader
+from django.test import TestCase
+
+from .base import MigrationsTestCase, connection
+
+log = logging.getLogger(__name__)
+
+
+class SpanishInquisition(MigrationsTestCase):
+    app = "api"
+    migration_prior = "scragly"
+    migration_target = "kosa"
+
+
+@patch("pydis_site.apps.api.tests.migrations.base.MigrationExecutor")
+class MigrationsTestCaseNoSideEffectsTests(TestCase):
+    """Tests the MigrationTestCase class with actual migration side effects disabled."""
+
+    def setUp(self):
+        """Set up an instance of MigrationsTestCase for use in tests."""
+        self.test_case = SpanishInquisition()
+
+    def test_missing_app_class_raises_value_error(self, _migration_executor):
+        """A MigrationsTestCase subclass should set the class-attribute `app`."""
+        class Spam(MigrationsTestCase):
+            pass
+
+        spam = Spam()
+        with self.assertRaises(ValueError, msg="The `app` attribute was not set."):
+            spam.setUpTestData()
+
+    def test_missing_migration_class_attributes_raise_value_error(self, _migration_executor):
+        """A MigrationsTestCase subclass should set both `migration_prior` and `migration_target`"""
+        class Eggs(MigrationsTestCase):
+            app = "api"
+            migration_target = "lemon"
+
+        class Bacon(MigrationsTestCase):
+            app = "api"
+            migration_prior = "mark"
+
+        instances = (Eggs(), Bacon())
+
+        exception_message = "Both ` migration_prior` and `migration_target` need to be set."
+        for instance in instances:
+            with self.subTest(
+                    migration_prior=instance.migration_prior,
+                    migration_target=instance.migration_target,
+            ):
+                with self.assertRaises(ValueError, msg=exception_message):
+                    instance.setUpTestData()
+
+    @patch(f"{__name__}.SpanishInquisition.setUpMigrationData")
+    @patch(f"{__name__}.SpanishInquisition.setUpPostMigrationData")
+    def test_migration_data_hooks_are_called_once(self, pre_hook, post_hook, _migration_executor):
+        """The `setUpMigrationData` and `setUpPostMigrationData` hooks should be called once."""
+        self.test_case.setUpTestData()
+        for hook in (pre_hook, post_hook):
+            with self.subTest(hook=repr(hook)):
+                hook.assert_called_once()
+
+    def test_migration_executor_is_instantiated_twice(self, migration_executor):
+        """The `MigrationExecutor` should be instantiated with the database connection twice."""
+        self.test_case.setUpTestData()
+
+        expected_args = [call(connection), call(connection)]
+        self.assertEqual(migration_executor.call_args_list, expected_args)
+
+    def test_project_state_is_loaded_for_correct_migration_files_twice(self, migration_executor):
+        """The `project_state` should first be loaded with `migrate_from`, then `migrate_to`."""
+        self.test_case.setUpTestData()
+
+        expected_args = [call(self.test_case.migrate_from), call(self.test_case.migrate_to)]
+        self.assertEqual(migration_executor().loader.project_state.call_args_list, expected_args)
+
+    def test_loader_build_graph_gets_called_once(self, migration_executor):
+        """We should rebuild the migration graph before applying the second set of migrations."""
+        self.test_case.setUpTestData()
+
+        migration_executor().loader.build_graph.assert_called_once()
+
+    def test_migration_executor_migrate_method_is_called_correctly_twice(self, migration_executor):
+        """The migrate method of the executor should be called twice with the correct arguments."""
+        self.test_case.setUpTestData()
+
+        self.assertEqual(migration_executor().migrate.call_count, 2)
+        calls = [call([('api', 'scragly')]), call([('api', 'kosa')])]
+        migration_executor().migrate.assert_has_calls(calls)
+
+
+class LifeOfBrian(MigrationsTestCase):
+    app = "api"
+    migration_prior = "0046_reminder_jump_url"
+    migration_target = "0048_add_infractions_unique_constraints_active"
+
+    @classmethod
+    def log_last_migration(cls):
+        """Parses the applied migrations dictionary to log the last applied migration."""
+        loader = MigrationLoader(connection)
+        api_migrations = [
+            migration for app, migration in loader.applied_migrations if app == cls.app
+        ]
+        last_migration = max(api_migrations, key=lambda name: int(name[:4]))
+        log.info(f"The last applied migration: {last_migration}")
+
+    @classmethod
+    def setUpMigrationData(cls, apps):
+        """Method that logs the last applied migration at this point."""
+        cls.log_last_migration()
+
+    @classmethod
+    def setUpPostMigrationData(cls, apps):
+        """Method that logs the last applied migration at this point."""
+        cls.log_last_migration()
+
+
+class MigrationsTestCaseMigrationTest(TestCase):
+    """Tests if `MigrationsTestCase` travels to the right points in the migration history."""
+
+    def test_migrations_test_case_travels_to_correct_migrations_in_history(self):
+        """The test case should first revert to `migration_prior`, then go to `migration_target`."""
+        brian = LifeOfBrian()
+
+        with self.assertLogs(log, level=logging.INFO) as logs:
+            brian.setUpTestData()
+
+            self.assertEqual(len(logs.records), 2)
+
+            for time_point, record in zip(("migration_prior", "migration_target"), logs.records):
+                with self.subTest(time_point=time_point):
+                    message = f"The last applied migration: {getattr(brian, time_point)}"
+                    self.assertEqual(record.getMessage(), message)
diff --git a/pydis_site/apps/api/tests/test_infractions.py b/pydis_site/apps/api/tests/test_infractions.py
index c58c32e2..7a54640e 100644
--- a/pydis_site/apps/api/tests/test_infractions.py
+++ b/pydis_site/apps/api/tests/test_infractions.py
@@ -1,6 +1,8 @@
 from datetime import datetime as dt, timedelta, timezone
+from unittest.mock import patch
 from urllib.parse import quote
 
+from django.db.utils import IntegrityError
 from django_hosts.resolvers import reverse
 
 from .base import APISubdomainTestCase
@@ -167,6 +169,12 @@ class CreationTests(APISubdomainTestCase):
             discriminator=1,
             avatar_hash=None
         )
+        cls.second_user = User.objects.create(
+            id=6,
+            name='carl',
+            discriminator=2,
+            avatar_hash=None
+        )
 
     def test_accepts_valid_data(self):
         url = reverse('bot:infraction-list', host='api')
@@ -305,6 +313,187 @@ class CreationTests(APISubdomainTestCase):
             'hidden': [f'{data["type"]} infractions must be hidden.']
         })
 
+    def test_returns_400_for_active_infraction_of_type_that_cannot_be_active(self):
+        """Test if the API rejects active infractions for types that cannot be active."""
+        url = reverse('bot:infraction-list', host='api')
+        restricted_types = (
+            ('note', True),
+            ('warning', False),
+            ('kick', False),
+        )
+
+        for infraction_type, hidden in restricted_types:
+            with self.subTest(infraction_type=infraction_type):
+                invalid_infraction = {
+                    'user': self.user.id,
+                    'actor': self.user.id,
+                    'type': infraction_type,
+                    'reason': 'Take me on!',
+                    'hidden': hidden,
+                    'active': True,
+                    'expires_at': None,
+                }
+                response = self.client.post(url, data=invalid_infraction)
+                self.assertEqual(response.status_code, 400)
+                self.assertEqual(
+                    response.json(),
+                    {'active': [f'{infraction_type} infractions cannot be active.']}
+                )
+
+    def test_returns_400_for_second_active_infraction_of_the_same_type(self):
+        """Test if the API rejects a second active infraction of the same type for a given user."""
+        url = reverse('bot:infraction-list', host='api')
+        active_infraction_types = ('mute', 'ban', 'superstar')
+
+        for infraction_type in active_infraction_types:
+            with self.subTest(infraction_type=infraction_type):
+                first_active_infraction = {
+                    'user': self.user.id,
+                    'actor': self.user.id,
+                    'type': infraction_type,
+                    'reason': 'Take me on!',
+                    'active': True,
+                    'expires_at': '2019-10-04T12:52:00+00:00'
+                }
+
+                # Post the first active infraction of a type and confirm it's accepted.
+                first_response = self.client.post(url, data=first_active_infraction)
+                self.assertEqual(first_response.status_code, 201)
+
+                second_active_infraction = {
+                    'user': self.user.id,
+                    'actor': self.user.id,
+                    'type': infraction_type,
+                    'reason': 'Take on me!',
+                    'active': True,
+                    'expires_at': '2019-10-04T12:52:00+00:00'
+                }
+                second_response = self.client.post(url, data=second_active_infraction)
+                self.assertEqual(second_response.status_code, 400)
+                self.assertEqual(
+                    second_response.json(),
+                    {
+                        'non_field_errors': [
+                            'This user already has an active infraction of this type.'
+                        ]
+                    }
+                )
+
+    def test_returns_201_for_second_active_infraction_of_different_type(self):
+        """Test if the API accepts a second active infraction of a different type than the first."""
+        url = reverse('bot:infraction-list', host='api')
+        first_active_infraction = {
+            'user': self.user.id,
+            'actor': self.user.id,
+            'type': 'mute',
+            'reason': 'Be silent!',
+            'hidden': True,
+            'active': True,
+            'expires_at': '2019-10-04T12:52:00+00:00'
+        }
+        second_active_infraction = {
+            'user': self.user.id,
+            'actor': self.user.id,
+            'type': 'ban',
+            'reason': 'Be gone!',
+            'hidden': True,
+            'active': True,
+            'expires_at': '2019-10-05T12:52:00+00:00'
+        }
+        # Post the first active infraction of a type and confirm it's accepted.
+        first_response = self.client.post(url, data=first_active_infraction)
+        self.assertEqual(first_response.status_code, 201)
+
+        # Post the first active infraction of a type and confirm it's accepted.
+        second_response = self.client.post(url, data=second_active_infraction)
+        self.assertEqual(second_response.status_code, 201)
+
+    def test_unique_constraint_raises_integrity_error_on_second_active_of_same_type(self):
+        """Do we raise `IntegrityError` for the second active infraction of a type for a user?"""
+        Infraction.objects.create(
+            user=self.user,
+            actor=self.user,
+            type="ban",
+            active=True,
+            reason="The first active ban"
+        )
+        with self.assertRaises(IntegrityError):
+            Infraction.objects.create(
+                user=self.user,
+                actor=self.user,
+                type="ban",
+                active=True,
+                reason="The second active ban"
+            )
+
+    def test_unique_constraint_accepts_active_infraction_after_inactive_infraction(self):
+        """Do we accept an active infraction if the others of the same type are inactive?"""
+        try:
+            Infraction.objects.create(
+                user=self.user,
+                actor=self.user,
+                type="ban",
+                active=False,
+                reason="The first inactive ban"
+            )
+            Infraction.objects.create(
+                user=self.user,
+                actor=self.user,
+                type="ban",
+                active=False,
+                reason="The second inactive ban"
+            )
+            Infraction.objects.create(
+                user=self.user,
+                actor=self.user,
+                type="ban",
+                active=True,
+                reason="The first active ban"
+            )
+        except IntegrityError:
+            self.fail("An unexpected IntegrityError was raised.")
+
+    @patch(f"{__name__}.Infraction")
+    def test_if_accepts_active_infraction_test_catches_integrity_error(self, infraction_patch):
+        """Does the test properly catch the IntegrityError and raise an AssertionError?"""
+        infraction_patch.objects.create.side_effect = IntegrityError
+        with self.assertRaises(AssertionError, msg="An unexpected IntegrityError was raised."):
+            self.test_unique_constraint_accepts_active_infraction_after_inactive_infraction()
+
+    def test_unique_constraint_accepts_second_active_of_different_type(self):
+        """Do we accept a second active infraction of a different type for a given user?"""
+        Infraction.objects.create(
+            user=self.user,
+            actor=self.user,
+            type="ban",
+            active=True,
+            reason="The first active ban"
+        )
+        Infraction.objects.create(
+            user=self.user,
+            actor=self.user,
+            type="mute",
+            active=True,
+            reason="The first active mute"
+        )
+
+    def test_unique_constraint_accepts_active_infractions_for_different_users(self):
+        """Do we accept two active infractions of the same type for two different users?"""
+        Infraction.objects.create(
+            user=self.user,
+            actor=self.user,
+            type="ban",
+            active=True,
+            reason="An active ban for the first user"
+        )
+        Infraction.objects.create(
+            user=self.second_user,
+            actor=self.second_user,
+            type="ban",
+            active=False,
+            reason="An active ban for the second user"
+        )
+
 
 class ExpandedTests(APISubdomainTestCase):
     @classmethod
@@ -318,12 +507,14 @@ class ExpandedTests(APISubdomainTestCase):
         cls.kick = Infraction.objects.create(
             user_id=cls.user.id,
             actor_id=cls.user.id,
-            type='kick'
+            type='kick',
+            active=False
         )
         cls.warning = Infraction.objects.create(
             user_id=cls.user.id,
             actor_id=cls.user.id,
-            type='warning'
+            type='warning',
+            active=False,
         )
 
     def check_expanded_fields(self, infraction):
diff --git a/pydis_site/apps/api/views.py b/pydis_site/apps/api/views.py
index 32583665..f0f7efa9 100644
--- a/pydis_site/apps/api/views.py
+++ b/pydis_site/apps/api/views.py
@@ -103,60 +103,46 @@ class RulesView(APIView):
                 f"`format` must be `html` or `md`, got `{format}`."
             )
 
-        discord_community_guidelines_link = self._format_link(
+        discord_community_guidelines = self._format_link(
             'Discord Community Guidelines',
             'https://discordapp.com/guidelines',
             link_format
         )
-        channels_page_link = self._format_link(
-            'channels page',
-            'https://pythondiscord.com/about/channels',
+        discord_tos = self._format_link(
+            'Terms Of Service',
+            'https://discordapp.com/guidelines',
             link_format
         )
-        google_translate_link = self._format_link(
-            'Google Translate',
-            'https://translate.google.com/',
+        pydis_coc = self._format_link(
+            'Python Discord Code of Conduct',
+            'https://pythondiscord.com/pages/code-of-conduct/',
             link_format
         )
 
         return Response([
-            "Be polite, and do not spam.",
-            f"Follow the {discord_community_guidelines_link}.",
             (
-                "Don't intentionally make other people uncomfortable - if "
-                "someone asks you to stop discussing something, you should stop."
+                f"Follow the {discord_community_guidelines} and {discord_tos}."
             ),
             (
-                "Be patient both with users asking "
-                "questions, and the users answering them."
+                f"Follow the {pydis_coc}."
             ),
             (
-                "We will not help you with anything that might break a law or the "
-                "terms of service of any other community, site, service, or "
-                "otherwise - No piracy, brute-forcing, captcha circumvention, "
-                "sneaker bots, or anything else of that nature."
+                "Listen to and respect staff members and their instructions."
             ),
             (
-                "Listen to and respect the staff members - we're "
-                "here to help, but we're all human beings."
+                "This is an English-speaking server, "
+                "so please speak English to the best of your ability."
             ),
             (
-                "All discussion should be kept within the relevant "
-                "channels for the subject - See the "
-                f"{channels_page_link} for more information."
+                "Do not provide or request help on projects that may break laws, "
+                "breach terms of services, be considered malicious/inappropriate "
+                "or be for graded coursework/exams."
             ),
             (
-                "This is an English-speaking server, so please speak English "
-                f"to the best of your ability - {google_translate_link} "
-                "should be fine if you're not sure."
+                "No spamming or unapproved advertising, including requests for paid work. "
+                "Open-source projects can be showcased in #show-your-projects."
             ),
             (
-                "Keep all discussions safe for work - No gore, nudity, sexual "
-                "soliciting, references to suicide, or anything else of that nature"
+                "Keep discussions relevant to channel topics and guidelines."
             ),
-            (
-                "We do not allow advertisements for communities (including "
-                "other Discord servers) or commercial projects - Contact "
-                "us directly if you want to discuss a partnership!"
-            )
         ])