fix: do not allow empty ('') constrain values.

related #640

lib/routes/admin-api/feature-schema.js

@@ -8,7 +8,12 @@ const nameSchema = joi.object().keys({ name: nameType });
 const constraintSchema = joi.object().keys({
     contextName: joi.string(),
     operator: joi.string(),
-    values: joi.array().items(joi.string()),
+    values: joi.array().items(
+        joi
+            .string()
+            .min(1)
+            .max(100),
+    ),
 });
 
 const strategiesSchema = joi.object().keys({

lib/routes/admin-api/feature-schema.test.js

@@ -172,3 +172,55 @@ test('should keep constraints', t => {
     t.deepEqual(value, toggle);
     t.falsy(error);
 });
+
+test('should not accept empty constraint values', t => {
+    const toggle = {
+        name: 'app.constraints.empty.value',
+        type: 'release',
+        enabled: false,
+        stale: false,
+        strategies: [
+            {
+                name: 'default',
+                constraints: [
+                    {
+                        contextName: 'environment',
+                        operator: 'IN',
+                        values: [''],
+                    },
+                ],
+            },
+        ],
+    };
+
+    const { error } = featureShema.validate(toggle);
+    t.deepEqual(
+        error.details[0].message,
+        '"strategies[0].constraints[0].values[0]" is not allowed to be empty',
+    );
+});
+
+test('should not accept empty list of constraint values', t => {
+    const toggle = {
+        name: 'app.constraints.empty.value.list',
+        type: 'release',
+        enabled: false,
+        stale: false,
+        strategies: [
+            {
+                name: 'default',
+                constraints: [
+                    {
+                        contextName: 'environment',
+                        operator: 'IN',
+                        values: [],
+                    },
+                ],
+            },
+        ],
+    };
+
+    const { value, error } = featureShema.validate(toggle);
+    t.deepEqual(value, toggle);
+    t.falsy(error);
+});