fix: found an edge case exporting variants (#2900)

## About the changes
When exporting v3, for variants backward compatibility, we need to find
one featureEnvironment and fetch variants from there.
In cases where the default environment is disabled (therefore does not
get variants per environment when added), it can be still be selected
for the export process. Therefore variants don't appear in the feature
when they should be there.

An e2e test that fails with the previous implementation was added to
validate the behavior

This comes from our support ticket 404

src/lib/services/state-service.ts

@@ -712,26 +712,35 @@ export default class StateService {
         const v4 = await this.exportV4({ ...opts, includeEnvironments: true });
         // undefined defaults to true
         if (opts.includeFeatureToggles !== false) {
-            const keepEnv = v4.environments
-                .filter((env) => env.enabled !== false)
-                .sort((e1, e2) => {
-                    if (e1.type !== 'production' || e2.type !== 'production') {
-                        if (e1.type === 'production') {
-                            return -1;
-                        } else if (e2.type === 'production') {
-                            return 1;
-                        }
-                    }
-                    return e1.sortOrder - e2.sortOrder;
-                })[0];
-
-            const featureEnvs = v4.featureEnvironments.filter(
-                (fE) => fE.environment === keepEnv.name,
+            const enabledEnvironments = v4.environments.filter(
+                (env) => env.enabled !== false,
             );
+
+            const featureAndEnvs = v4.featureEnvironments.map((fE) => {
+                const envDetails = enabledEnvironments.find(
+                    (env) => fE.environment === env.name,
+                );
+                return { ...fE, ...envDetails, active: fE.enabled };
+            });
             v4.features = v4.features.map((f) => {
-                const variants = featureEnvs.find(
-                    (fe) => fe.featureName === f.name,
-                )?.variants;
+                const variants = featureAndEnvs
+                    .sort((e1, e2) => {
+                        if (e1.active !== e2.active) {
+                            return e1.active ? -1 : 1;
+                        }
+                        if (
+                            e1.type !== 'production' ||
+                            e2.type !== 'production'
+                        ) {
+                            if (e1.type === 'production') {
+                                return -1;
+                            } else if (e2.type === 'production') {
+                                return 1;
+                            }
+                        }
+                        return e1.sortOrder - e2.sortOrder;
+                    })
+                    .find((fe) => fe.featureName === f.name)?.variants;
                 return { ...f, variants };
             });
             v4.featureEnvironments = v4.featureEnvironments.map((fe) => {
@@ -742,6 +751,10 @@ export default class StateService {
         // only if explicitly set to false (i.e. undefined defaults to true)
         if (opts.includeEnvironments === false) {
             delete v4.environments;
+        } else {
+            if (v4.environments.length === 0) {
+                throw Error('Unable to export without enabled environments');
+            }
         }
         v4.version = 3;
         return v4;

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

@@ -5,6 +5,7 @@ import { DEFAULT_ENV } from '../../../../lib/util/constants';
 import { collectIds } from '../../../../lib/util/collect-ids';
 import { ApiTokenType } from '../../../../lib/types/models/api-token';
 import variantsv3 from '../../../examples/variantsexport_v3.json';
+import v3WithDefaultDisabled from '../../../examples/exported3-with-default-disabled.json';
 import { StateService } from '../../../../lib/services';
 
 const importData = require('../../../examples/import.json');
@@ -464,3 +465,36 @@ test(`should handle v3 export with variants in features`, async () => {
         .sort();
     expect(exportedFeatures).toStrictEqual(importedFeatures);
 });
+
+test(`should handle v3 export with variants in features and only 1 env`, async () => {
+    app.services.stateService = new StateService(db.stores, {
+        getLogger,
+        flagResolver: {
+            isEnabled: () => false,
+            getAll: () => ({}),
+        },
+    });
+
+    await app.request
+        .post('/api/admin/state/import?drop=true')
+        .attach(
+            'file',
+            'src/test/examples/exported3-with-default-disabled.json',
+        )
+        .expect(202);
+
+    const exported = await app.services.stateService.export({});
+    let exportedFeatures = exported.features
+        .map((f) => {
+            delete f.createdAt;
+            return f;
+        })
+        .sort();
+    let importedFeatures = v3WithDefaultDisabled.features
+        .map((f) => {
+            delete f.createdAt;
+            return f;
+        })
+        .sort();
+    expect(exportedFeatures).toStrictEqual(importedFeatures);
+});

src/test/examples/exported3-with-default-disabled.json

@@ -0,0 +1,88 @@
+{
+  "version": 3,
+  "features": [
+    {
+      "name": "test-variants-postman",
+      "description": "",
+      "type": "experiment",
+      "project": "default",
+      "stale": false,
+      "createdAt": "2023-01-13T09:17:43.989Z",
+      "lastSeenAt": null,
+      "impressionData": false,
+      "archivedAt": null,
+      "archived": false,
+      "variants": [
+        {
+          "name": "fake",
+          "weight": 500,
+          "payload": {
+            "type": "string",
+            "value": "123"
+          },
+          "overrides": [],
+          "stickiness": "default",
+          "weightType": "variable"
+        },
+        {
+          "name": "fake2",
+          "weight": 500,
+          "payload": {
+            "type": "json",
+            "value": "{\"hello\":\"world\"}"
+          },
+          "overrides": [],
+          "stickiness": "default",
+          "weightType": "variable"
+        }
+      ]
+    }
+  ],
+  "strategies": [],
+  "projects": [
+    {
+      "id": "default",
+      "name": "Default",
+      "description": "Default project",
+      "createdAt": "2023-01-10T13:11:03.260Z",
+      "health": 100,
+      "updatedAt": "2023-01-13T09:09:12.494Z"
+    }
+  ],
+  "tagTypes": [],
+  "tags": [],
+  "featureTags": [],
+  "featureStrategies": [],
+  "environments": [
+    {
+      "name": "default",
+      "type": "production",
+      "sortOrder": 1,
+      "enabled": false,
+      "protected": true
+    },
+    {
+      "name": "development",
+      "type": "development",
+      "sortOrder": 100,
+      "enabled": true,
+      "protected": false
+    },
+    {
+      "name": "production",
+      "type": "production",
+      "sortOrder": 200,
+      "enabled": true,
+      "protected": false
+    }
+  ],
+  "featureEnvironments": [
+    {
+      "enabled": true,
+      "featureName": "test-variants-postman",
+      "environment": "development"
+    }
+  ],
+  "segments": [],
+  "featureStrategySegments": []
+}