chore: remove deprecated strategies and allow deprecate default (#3575)

## About the changes
Improvements around strategies to steer users toward using [strategy
constraints](https://docs.getunleash.io/reference/strategy-constraints)
instead of [custom
strategies](https://docs.getunleash.io/reference/custom-activation-strategies)


Related to #1265 

Important changes:
1.[ Ability to deprecate default
strategy](https://github.com/Unleash/unleash/pull/3575/files#diff-3b49e566565b01580ff7a15f662d2cb824547fdfb3935d0a0baa7fae326d28d6L232-L235)
2. [Remove strategies that were deprecated in v4 only if they're not
used](https://github.com/Unleash/unleash/pull/3575/files#diff-a04de7adf327c48d54b030bed70d9b1d62ff14df3efc668eb6897a210124ebe0R7-R10)
3. [Fresh Unleash installations will not include deprecated strategies
from
v4](https://github.com/Unleash/unleash/pull/3575/files#diff-46265b0d51725a5acbf251589b98a8970e45d3a1c6f3d7ea77bdcc3714e672d8L31-L78)
4. [Deprecate userWithId
strategy](https://github.com/Unleash/unleash/pull/3575/files#diff-a04de7adf327c48d54b030bed70d9b1d62ff14df3efc668eb6897a210124ebe0R13)
(note: if in use it will continue to work, it'll be not listed when
selecting strategies for a feature toggle).
5. [Switch the order of strategies to make gradual rollout first and
change the comment to suggest using gradual rollout instead of other
existing
strategies](https://github.com/Unleash/unleash/pull/3575/files#diff-a04de7adf327c48d54b030bed70d9b1d62ff14df3efc668eb6897a210124ebe0R16-R18)

frontend/src/component/strategies/StrategiesList/StrategiesList.tsx

@@ -216,7 +216,6 @@ export const StrategiesList = () => {
                         <StrategySwitch
                             deprecated={original.deprecated}
                             onToggle={onToggle(original)}
-                            disabled={original.name === 'default'}
                         />
                         <ActionCell.Divider />
                         <StrategyEditButton

src/lib/routes/admin-api/strategy.test.ts

@@ -207,11 +207,3 @@ test('reactivating a non-existent strategy yields 404', async () => {
         .set('Content-Type', 'application/json')
         .expect(404);
 });
-test("deprecating 'default' strategy will yield 403", async () => {
-    jest.spyOn(global.console, 'error').mockImplementation(() => jest.fn());
-    const { request, base } = await getSetup();
-    return request
-        .post(`${base}/api/admin/strategies/default/deprecate`)
-        .set('Content-Type', 'application/json')
-        .expect(403);
-});

src/lib/routes/admin-api/strategy.ts

@@ -229,11 +229,6 @@ class StrategyController extends Controller {
         const userName = extractUsername(req);
         const { strategyName } = req.params;
 
-        if (strategyName === 'default') {
-            res.status(403).end();
-            return;
-        }
-
         await this.strategyService.deprecateStrategy(strategyName, userName);
         res.status(200).end();
     }

src/migrations/20230420125500-v5-strategy-changes.js

@@ -0,0 +1,72 @@
+'use strict';
+
+exports.up = function (db, callback) {
+    db.runSql(
+        `
+        -- delete deprecated strategies still present in v4
+        delete from strategies 
+            where name in ('gradualRolloutUserId', 'gradualRolloutRandom', 'gradualRolloutSessionId') 
+            and deprecated 
+            and not exists (select * from feature_strategies where strategy_name = name limit 1);
+        
+        -- deprecate strategies on v5
+        update strategies set deprecated = true where name in ('userWithId');
+        
+        -- update strategy descriptions and sort order
+        update strategies set sort_order = 1, description = 'This strategy turns on / off for your entire userbase. Prefer using "Gradual rollout" strategy (100%=on, 0%=off).' WHERE name = 'default';
+        update strategies set sort_order = 0 WHERE name = 'flexibleRollout';
+        update strategies set description = 'Enable the feature for a specific set of userIds. Prefer using "Gradual rollout" strategy with user id constraints.' WHERE name = 'userWithId';
+        `,
+        callback,
+    );
+};
+
+exports.down = function (db, callback) {
+    db.runSql(
+        `
+        -- restore deleted strategies
+        insert into strategies (name, description, parameters, deprecated, sort_order) values
+            ('gradualRolloutRandom', 'Randomly activate the feature toggle. No stickiness.', [
+                {
+                  "name": "percentage",
+                  "type": "percentage",
+                  "description": "",
+                  "required": false
+                }
+              ], true, 3),
+            ('gradualRolloutSessionId', 'Gradually activate feature toggle. Stickiness based on session id.', [
+                {
+                  "name": "percentage",
+                  "type": "percentage",
+                  "description": "",
+                  "required": false
+                },
+                {
+                  "name": "groupId",
+                  "type": "string",
+                  "description": "Used to define a activation groups, which allows you to correlate across feature toggles.",
+                  "required": true
+                }
+              ], true, 4),
+            ('gradualRolloutUserId', 'Gradually activate feature toggle for logged in users. Stickiness based on user id.', [
+                {
+                  "name": "percentage",
+                  "type": "percentage",
+                  "description": "",
+                  "required": false
+                },
+                {
+                  "name": "groupId",
+                  "type": "string",
+                  "description": "Used to define a activation groups, which allows you to correlate across feature toggles.",
+                  "required": true
+                }
+              ], true, 5);
+
+        -- revert sort order
+        update strategies set sort_order = 0 WHERE name = 'default';
+        update strategies set sort_order = 1 WHERE name = 'flexibleRollout';
+        `,
+        callback,
+    );
+};

src/migrations/default-strategies.json

@@ -28,54 +28,6 @@
       }
     ]
   },
-  {
-    "name": "gradualRolloutRandom",
-    "description": "Randomly activate the feature toggle. No stickiness.",
-    "parameters": [
-      {
-        "name": "percentage",
-        "type": "percentage",
-        "description": "",
-        "required": false
-      }
-    ]
-  },
-  {
-    "name": "gradualRolloutSessionId",
-    "description": "Gradually activate feature toggle. Stickiness based on session id.",
-    "parameters": [
-      {
-        "name": "percentage",
-        "type": "percentage",
-        "description": "",
-        "required": false
-      },
-      {
-        "name": "groupId",
-        "type": "string",
-        "description": "Used to define a activation groups, which allows you to correlate across feature toggles.",
-        "required": true
-      }
-    ]
-  },
-  {
-    "name": "gradualRolloutUserId",
-    "description": "Gradually activate feature toggle for logged in users. Stickiness based on user id.",
-    "parameters": [
-      {
-        "name": "percentage",
-        "type": "percentage",
-        "description": "",
-        "required": false
-      },
-      {
-        "name": "groupId",
-        "type": "string",
-        "description": "Used to define a activation groups, which allows you to correlate across feature toggles.",
-        "required": true
-      }
-    ]
-  },
   {
     "name": "remoteAddress",
     "description": "Active for remote addresses defined in the IPs list.",

src/test/e2e/api/admin/strategy.e2e.test.ts

@@ -171,15 +171,6 @@ test('can reactivate a deprecated strategy', async () => {
         .expect((res) => expect(res.body.deprecated).toBe(false));
 });
 
-test('cannot deprecate default strategy', async () => {
-    expect.assertions(0);
-
-    await app.request
-        .post('/api/admin/strategies/default/deprecate')
-        .set('Content-Type', 'application/json')
-        .expect(403);
-});
-
 test('can update a exiting strategy with deprecated', async () => {
     await app.request
         .post('/api/admin/strategies')

src/test/e2e/api/client/feature.optimal304.e2e.test.ts

@@ -122,14 +122,14 @@ test('returns calculated hash', async () => {
         .get('/api/client/features')
         .expect('Content-Type', /json/)
         .expect(200);
-    expect(res.headers.etag).toBe('"ae443048:19"');
+    expect(res.headers.etag).toBe('"ae443048:16"');
-    expect(res.body.meta.etag).toBe('"ae443048:19"');
+    expect(res.body.meta.etag).toBe('"ae443048:16"');
 });
 
 test('returns 304 for pre-calculated hash', async () => {
     return app.request
         .get('/api/client/features')
-        .set('if-none-match', '"ae443048:19"')
+        .set('if-none-match', '"ae443048:16"')
         .expect(304);
 });
 
@@ -146,9 +146,9 @@ test('returns 200 when content updates and hash does not match anymore', async (
 
     const res = await app.request
         .get('/api/client/features')
-        .set('if-none-match', 'ae443048:19')
+        .set('if-none-match', 'ae443048:16')
         .expect(200);
 
-    expect(res.headers.etag).toBe('"ae443048:20"');
+    expect(res.headers.etag).toBe('"ae443048:17"');
-    expect(res.body.meta.etag).toBe('"ae443048:20"');
+    expect(res.body.meta.etag).toBe('"ae443048:17"');
 });