diff --git a/app/soapbox/reducers/__tests__/accounts-test.js b/app/soapbox/reducers/__tests__/accounts-test.js
new file mode 100644
index 000000000..c85c998f0
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/accounts-test.js
@@ -0,0 +1,8 @@
+import reducer from '../accounts';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('accounts reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/accounts_counters-test.js b/app/soapbox/reducers/__tests__/accounts_counters-test.js
new file mode 100644
index 000000000..f6c9e3bb0
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/accounts_counters-test.js
@@ -0,0 +1,8 @@
+import reducer from '../accounts_counters';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('accounts_counters reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/alerts-test.js b/app/soapbox/reducers/__tests__/alerts-test.js
new file mode 100644
index 000000000..988859d8a
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/alerts-test.js
@@ -0,0 +1,8 @@
+import reducer from '../alerts';
+import { List as ImmutableList } from 'immutable';
+
+describe('alerts reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableList());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/compose-test.js b/app/soapbox/reducers/__tests__/compose-test.js
new file mode 100644
index 000000000..9c13c3e71
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/compose-test.js
@@ -0,0 +1,30 @@
+import reducer from '../compose';
+
+describe('compose reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {}).toJS()).toMatchObject({
+      mounted: 0,
+      sensitive: false,
+      spoiler: false,
+      spoiler_text: '',
+      privacy: null,
+      text: '',
+      focusDate: null,
+      caretPosition: null,
+      in_reply_to: null,
+      is_composing: false,
+      is_submitting: false,
+      is_changing_upload: false,
+      is_uploading: false,
+      progress: 0,
+      media_attachments: [],
+      poll: null,
+      suggestion_token: null,
+      suggestions: [],
+      default_privacy: 'public',
+      default_sensitive: false,
+      idempotencyKey: null,
+      tagHistory: [],
+    });
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/contexts-test.js b/app/soapbox/reducers/__tests__/contexts-test.js
new file mode 100644
index 000000000..3130f2e53
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/contexts-test.js
@@ -0,0 +1,11 @@
+import reducer from '../contexts';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('contexts reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      inReplyTos: ImmutableMap(),
+      replies: ImmutableMap(),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/conversations-test.js b/app/soapbox/reducers/__tests__/conversations-test.js
new file mode 100644
index 000000000..4df9d8322
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/conversations-test.js
@@ -0,0 +1,13 @@
+import reducer from '../conversations';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('conversations reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      items: ImmutableList(),
+      isLoading: false,
+      hasMore: true,
+      mounted: false,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/custom_emojis-test.js b/app/soapbox/reducers/__tests__/custom_emojis-test.js
new file mode 100644
index 000000000..17cd1248f
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/custom_emojis-test.js
@@ -0,0 +1,8 @@
+import reducer from '../custom_emojis';
+import { List as ImmutableList } from 'immutable';
+
+describe('custom_emojis reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableList());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/domain_lists-test.js b/app/soapbox/reducers/__tests__/domain_lists-test.js
new file mode 100644
index 000000000..94003121c
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/domain_lists-test.js
@@ -0,0 +1,12 @@
+import reducer from '../domain_lists';
+import { Map as ImmutableMap, OrderedSet as ImmutableOrderedSet } from 'immutable';
+
+describe('domain_lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      blocks: ImmutableMap({
+        items: ImmutableOrderedSet(),
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/dropdown_menu-test.js b/app/soapbox/reducers/__tests__/dropdown_menu-test.js
new file mode 100644
index 000000000..c618adf52
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/dropdown_menu-test.js
@@ -0,0 +1,12 @@
+import reducer from '../dropdown_menu';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('dropdown_menu reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      openId: null,
+      placement: null,
+      keyboard: false,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/filters-test.js b/app/soapbox/reducers/__tests__/filters-test.js
new file mode 100644
index 000000000..1d0eab250
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/filters-test.js
@@ -0,0 +1,8 @@
+import reducer from '../filters';
+import { List as ImmutableList } from 'immutable';
+
+describe('filters reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableList());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/group_editor-test.js b/app/soapbox/reducers/__tests__/group_editor-test.js
new file mode 100644
index 000000000..2008d6fd9
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/group_editor-test.js
@@ -0,0 +1,15 @@
+import reducer from '../group_editor';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('group_editor reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      groupId: null,
+      isSubmitting: false,
+      isChanged: false,
+      title: '',
+      description: '',
+      coverImage: null,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/group_lists-test.js b/app/soapbox/reducers/__tests__/group_lists-test.js
new file mode 100644
index 000000000..802c394ce
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/group_lists-test.js
@@ -0,0 +1,12 @@
+import reducer from '../group_lists';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('group_lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      featured: ImmutableList(),
+      member: ImmutableList(),
+      admin: ImmutableList(),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/group_relationships-test.js b/app/soapbox/reducers/__tests__/group_relationships-test.js
new file mode 100644
index 000000000..d0fead807
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/group_relationships-test.js
@@ -0,0 +1,8 @@
+import reducer from '../group_relationships';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('group_relationships reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/groups-test.js b/app/soapbox/reducers/__tests__/groups-test.js
new file mode 100644
index 000000000..933d7cf0e
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/groups-test.js
@@ -0,0 +1,8 @@
+import reducer from '../groups';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('groups reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/height_cache-test.js b/app/soapbox/reducers/__tests__/height_cache-test.js
new file mode 100644
index 000000000..4873509e5
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/height_cache-test.js
@@ -0,0 +1,8 @@
+import reducer from '../height_cache';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('height_cache reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/identity_proofs-test.js b/app/soapbox/reducers/__tests__/identity_proofs-test.js
new file mode 100644
index 000000000..d4d159847
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/identity_proofs-test.js
@@ -0,0 +1,8 @@
+import reducer from '../identity_proofs';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('identity_proofs reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/instance-test.js b/app/soapbox/reducers/__tests__/instance-test.js
new file mode 100644
index 000000000..cba12c648
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/instance-test.js
@@ -0,0 +1,16 @@
+import reducer from '../instance';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('instance reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      max_toot_chars: 500,
+      poll_limits: ImmutableMap({
+        max_expiration: 2629746,
+        max_option_chars: 25,
+        max_options: 4,
+        min_expiration: 300,
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/list_adder-test.js b/app/soapbox/reducers/__tests__/list_adder-test.js
new file mode 100644
index 000000000..4fcd1c3d2
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/list_adder-test.js
@@ -0,0 +1,16 @@
+import reducer from '../list_adder';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('list_adder reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      accountId: null,
+
+      lists: ImmutableMap({
+        items: ImmutableList(),
+        loaded: false,
+        isLoading: false,
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/list_editor-test.js b/app/soapbox/reducers/__tests__/list_editor-test.js
new file mode 100644
index 000000000..46dc79c3f
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/list_editor-test.js
@@ -0,0 +1,24 @@
+import reducer from '../list_editor';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('list_editor reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      listId: null,
+      isSubmitting: false,
+      isChanged: false,
+      title: '',
+
+      accounts: ImmutableMap({
+        items: ImmutableList(),
+        loaded: false,
+        isLoading: false,
+      }),
+
+      suggestions: ImmutableMap({
+        value: '',
+        items: ImmutableList(),
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/lists-test.js b/app/soapbox/reducers/__tests__/lists-test.js
new file mode 100644
index 000000000..52a7d28f0
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/lists-test.js
@@ -0,0 +1,8 @@
+import reducer from '../lists';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/me-test.js b/app/soapbox/reducers/__tests__/me-test.js
new file mode 100644
index 000000000..2c434dca4
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/me-test.js
@@ -0,0 +1,7 @@
+import reducer from '../me';
+
+describe('me reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(null);
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/media_attachments.js b/app/soapbox/reducers/__tests__/media_attachments.js
new file mode 100644
index 000000000..95ef822b1
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/media_attachments.js
@@ -0,0 +1,27 @@
+import reducer from '../media_attachments';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('media_attachments reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      accept_content_types: ImmutableList([
+        '.jpg',
+        '.jpeg',
+        '.png',
+        '.gif',
+        '.webp',
+        '.webm',
+        '.mp4',
+        '.m4v',
+        '.mov',
+        'image/jpeg',
+        'image/png',
+        'image/gif',
+        'image/webp',
+        'video/webm',
+        'video/mp4',
+        'video/quicktime',
+      ]),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/meta-test.js b/app/soapbox/reducers/__tests__/meta-test.js
new file mode 100644
index 000000000..59542cba5
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/meta-test.js
@@ -0,0 +1,8 @@
+import reducer from '../meta';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('meta reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/modal-test.js b/app/soapbox/reducers/__tests__/modal-test.js
new file mode 100644
index 000000000..7b60bb381
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/modal-test.js
@@ -0,0 +1,10 @@
+import reducer from '../modal';
+
+describe('modal reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual({
+      modalType: null,
+      modalProps: {},
+    });
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/mutes-test.js b/app/soapbox/reducers/__tests__/mutes-test.js
new file mode 100644
index 000000000..8dd74dec0
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/mutes-test.js
@@ -0,0 +1,14 @@
+import reducer from '../mutes';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('mutes reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      new: ImmutableMap({
+        isSubmitting: false,
+        account: null,
+        notifications: true,
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/notifications-test.js b/app/soapbox/reducers/__tests__/notifications-test.js
new file mode 100644
index 000000000..b73648026
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/notifications-test.js
@@ -0,0 +1,17 @@
+import reducer from '../notifications';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('notifications reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      items: ImmutableList(),
+      hasMore: true,
+      top: false,
+      unread: 0,
+      isLoading: false,
+      queuedNotifications: ImmutableList(),
+      totalQueuedNotificationsCount: 0,
+      lastRead: -1,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/patron-test.js b/app/soapbox/reducers/__tests__/patron-test.js
new file mode 100644
index 000000000..1cb8c728d
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/patron-test.js
@@ -0,0 +1,8 @@
+import reducer from '../patron';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('patron reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/polls-test.js b/app/soapbox/reducers/__tests__/polls-test.js
new file mode 100644
index 000000000..d78698b93
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/polls-test.js
@@ -0,0 +1,8 @@
+import reducer from '../polls';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('polls reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/push_notifications-test.js b/app/soapbox/reducers/__tests__/push_notifications-test.js
new file mode 100644
index 000000000..7c47f4dd7
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/push_notifications-test.js
@@ -0,0 +1,19 @@
+import reducer from '../push_notifications';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('push_notifications reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      subscription: null,
+      alerts: new ImmutableMap({
+        follow: false,
+        favourite: false,
+        reblog: false,
+        mention: false,
+        poll: false,
+      }),
+      isSubscribed: false,
+      browserSupport: false,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/relationships-test.js b/app/soapbox/reducers/__tests__/relationships-test.js
new file mode 100644
index 000000000..3d74e5077
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/relationships-test.js
@@ -0,0 +1,8 @@
+import reducer from '../relationships';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('relationships reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/reports-test.js b/app/soapbox/reducers/__tests__/reports-test.js
new file mode 100644
index 000000000..761128786
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/reports-test.js
@@ -0,0 +1,17 @@
+import reducer from '../reports';
+import { Map as ImmutableMap, Set as ImmutableSet } from 'immutable';
+
+describe('reports reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      new: ImmutableMap({
+        isSubmitting: false,
+        account_id: null,
+        status_ids: ImmutableSet(),
+        comment: '',
+        forward: false,
+        block: false,
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/search-test.js b/app/soapbox/reducers/__tests__/search-test.js
new file mode 100644
index 000000000..fb74f1473
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/search-test.js
@@ -0,0 +1,13 @@
+import reducer from '../search';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('search reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      value: '',
+      submitted: false,
+      hidden: false,
+      results: ImmutableMap(),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/settings-test.js b/app/soapbox/reducers/__tests__/settings-test.js
new file mode 100644
index 000000000..897dfb556
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/settings-test.js
@@ -0,0 +1,10 @@
+import reducer from '../settings';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('settings reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      saved: true,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/sidebar-test.js b/app/soapbox/reducers/__tests__/sidebar-test.js
new file mode 100644
index 000000000..09cbc8d21
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/sidebar-test.js
@@ -0,0 +1,7 @@
+import reducer from '../sidebar';
+
+describe('sidebar reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual({});
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/soapbox-test.js b/app/soapbox/reducers/__tests__/soapbox-test.js
new file mode 100644
index 000000000..f0829d66d
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/soapbox-test.js
@@ -0,0 +1,8 @@
+import reducer from '../soapbox';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('soapbox reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/status_lists-test.js b/app/soapbox/reducers/__tests__/status_lists-test.js
new file mode 100644
index 000000000..b996228a1
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/status_lists-test.js
@@ -0,0 +1,19 @@
+import reducer from '../status_lists';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('status_lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      favourites: ImmutableMap({
+        next: null,
+        loaded: false,
+        items: ImmutableList(),
+      }),
+      pins: ImmutableMap({
+        next: null,
+        loaded: false,
+        items: ImmutableList(),
+      }),
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/statuses-test.js b/app/soapbox/reducers/__tests__/statuses-test.js
new file mode 100644
index 000000000..00687224a
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/statuses-test.js
@@ -0,0 +1,8 @@
+import reducer from '../statuses';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('statuses reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/suggestions-test.js b/app/soapbox/reducers/__tests__/suggestions-test.js
new file mode 100644
index 000000000..60a7b22a1
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/suggestions-test.js
@@ -0,0 +1,11 @@
+import reducer from '../suggestions';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('suggestions reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      items: ImmutableList(),
+      isLoading: false,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/timelines-test.js b/app/soapbox/reducers/__tests__/timelines-test.js
new file mode 100644
index 000000000..0bf748dc7
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/timelines-test.js
@@ -0,0 +1,8 @@
+import reducer from '../timelines';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('timelines reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap());
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/trends-test.js b/app/soapbox/reducers/__tests__/trends-test.js
new file mode 100644
index 000000000..9c14da46b
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/trends-test.js
@@ -0,0 +1,11 @@
+import reducer from '../trends';
+import { Map as ImmutableMap, List as ImmutableList } from 'immutable';
+
+describe('trends reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      items: ImmutableList(),
+      isLoading: false,
+    }));
+  });
+});
diff --git a/app/soapbox/reducers/__tests__/user_lists-test.js b/app/soapbox/reducers/__tests__/user_lists-test.js
new file mode 100644
index 000000000..feaaca3e6
--- /dev/null
+++ b/app/soapbox/reducers/__tests__/user_lists-test.js
@@ -0,0 +1,18 @@
+import reducer from '../user_lists';
+import { Map as ImmutableMap } from 'immutable';
+
+describe('user_lists reducer', () => {
+  it('should return the initial state', () => {
+    expect(reducer(undefined, {})).toEqual(ImmutableMap({
+      followers: ImmutableMap(),
+      following: ImmutableMap(),
+      reblogged_by: ImmutableMap(),
+      favourited_by: ImmutableMap(),
+      follow_requests: ImmutableMap(),
+      blocks: ImmutableMap(),
+      mutes: ImmutableMap(),
+      groups: ImmutableMap(),
+      groups_removed_accounts: ImmutableMap(),
+    }));
+  });
+});