fix: multiple custom strategies calculation (#85)

Author: sighphyre

java-engine/src/test/java/io/getunleash/engine/CustomStrategiesEvaluatorTest.java

@@ -2,6 +2,7 @@
 
 import static io.getunleash.engine.TestStrategies.alwaysFails;
 import static io.getunleash.engine.TestStrategies.alwaysTrue;
+import static io.getunleash.engine.TestStrategies.onlyTrueIfParameterValueMatchesContext;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.*;
 import static org.junit.jupiter.params.provider.Arguments.of;
@@ -43,25 +44,25 @@ private static Stream<Arguments> twoStrategies() {
         of(
             alwaysTrue("custom"),
             alwaysFails("cus-tom"),
-            Map.of("customStrategy1", false, "customStrategy2", true)),
+            Map.of("customStrategy1", true, "customStrategy2", false)),
         of(
             alwaysFails("custom"),
             alwaysTrue("cus-tom"),
-            Map.of("customStrategy1", true, "customStrategy2", false)),
+            Map.of("customStrategy1", false, "customStrategy2", true)),
         of(
             alwaysTrue("wrongName"),
             alwaysTrue("wrongName"),
             Map.of("customStrategy1", false, "customStrategy2", false)),
         of(
             alwaysTrue("custom"),
             alwaysTrue("custom"),
-            Map.of("customStrategy1", false, "customStrategy2", true)));
+            Map.of("customStrategy1", true, "customStrategy2", false)));
   }
 
   private static Stream<Arguments> singleStrategy() {
     return Stream.of(
-        of("custom", Map.of("customStrategy1", false, "customStrategy2", true)),
-        of("cus-tom", Map.of("customStrategy1", true, "customStrategy2", false)),
+        of("custom", Map.of("customStrategy1", true, "customStrategy2", false)),
+        of("cus-tom", Map.of("customStrategy1", false, "customStrategy2", true)),
         of("unknown", Map.of("customStrategy1", false, "customStrategy2", false)));
   }
 
@@ -105,4 +106,16 @@ void faultyStrategy_shouldEvalToFalse() throws IOException, YggdrasilInvalidInpu
         Map.of("customStrategy1", false, "customStrategy2", false),
         unleashEngine.customStrategiesEvaluatorEval("Feature.Custom.Strategies", new Context()));
   }
+
+  @Test
+  void repeated_strategy_with_different_parameters_should_evaluate_separately()
+      throws IOException, YggdrasilInvalidInputException {
+    UnleashEngine unleashEngine =
+        new UnleashEngine(
+            List.of(onlyTrueIfParameterValueMatchesContext("myFancyStrategy", "myFancy")));
+    unleashEngine.takeState(ResourceReader.readResourceAsString("repeated_custom_strategy.json"));
+    var context = new Context();
+    context.setProperties(Map.of("myFancy", "one"));
+    assertThat(unleashEngine.customStrategiesEvaluatorEval("repeated.custom", context)).hasSize(2);
+  }
 }

java-engine/src/test/java/io/getunleash/engine/TestStrategies.java

@@ -53,4 +53,19 @@ public boolean isEnabled(Map<String, String> parameters, Context context) {
       }
     };
   }
+
+  static IStrategy onlyTrueIfParameterValueMatchesContext(
+      String strategyName, String parameterName) {
+    return new IStrategy() {
+      @Override
+      public String getName() {
+        return strategyName;
+      }
+
+      @Override
+      public boolean isEnabled(Map<String, String> parameters, Context context) {
+        return context.getProperties().get(parameterName).equals(parameters.get(parameterName));
+      }
+    };
+  }
 }

java-engine/src/test/resources/custom-strategy-tests.json

@@ -82,6 +82,25 @@
       "variants": [],
       "description": "",
       "impressionData": false
+    },
+    {
+      "name": "repeated.custom",
+      "enabled": true,
+      "strategies": [
+        {
+          "name": "myFancyStrategy",
+          "parameters": {
+            "myFancy": "one"
+          }
+
+        },
+        {
+          "name": "myFancyStrategy",
+          "parameters": {
+            "myFancy": "two"
+          }
+        }
+      ]
     }
   ]
 }

java-engine/src/test/resources/repeated_custom_strategy.json

@@ -0,0 +1,24 @@
+{
+  "version": 2,
+  "features": [
+    {
+      "name": "repeated.custom",
+      "enabled": true,
+      "strategies": [
+        {
+          "name": "myFancyStrategy",
+          "parameters": {
+            "myFancy": "one"
+          }
+
+        },
+        {
+          "name": "myFancyStrategy",
+          "parameters": {
+            "myFancy": "two"
+          }
+        }
+      ]
+    }
+  ]
+}

yggdrasilffi/src/flat/mod.rs

@@ -110,7 +110,7 @@ pub unsafe fn flat_take_state(engine_pointer: *mut c_void, toggles_pointer: *con
                             .collect();
                         (strategy.name.clone(), params)
                     })
-                    .collect::<BTreeMap<_, _>>();
+                    .collect::<Vec<_>>();
                 (name, strategies)
             })
             .collect::<BTreeMap<_, _>>();

yggdrasilffi/src/flat/serialisation.rs

@@ -40,10 +40,12 @@ pub struct ResponseMessage<T> {
     pub impression_data: bool,
 }
 
+pub type ParsedStrategies = BTreeMap<String, Vec<(String, BTreeMap<String, String>)>>;
+
 pub struct TakeStateResult {
     pub warnings: Vec<EvalWarning>,
     pub error: Option<String>,
-    pub feature_strategies_map: BTreeMap<String, BTreeMap<String, BTreeMap<String, String>>>,
+    pub feature_strategies_map: ParsedStrategies,
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize)]