JS: Update Generators test

Data flow difference is benign

Author: asgerf

javascript/ql/test/library-tests/Generators/DataFlow.expected

@@ -0,0 +1,5 @@
+legacyDataFlowDifference
+| generators.js:2:16:2:23 | "source" | generators.js:37:10:37:10 | e | only flow with OLD data flow library |
+| generators.js:2:16:2:23 | "source" | generators.js:46:10:46:10 | e | only flow with NEW data flow library |
+| generators.js:2:16:2:23 | "source" | generators.js:51:10:51:10 | e | only flow with NEW data flow library |
+consistencyIssue

javascript/ql/test/library-tests/Generators/DataFlow.ql

@@ -1,12 +1,28 @@
 import javascript
 import testUtilities.ConsistencyChecking
 
-class GeneratorFlowConfig extends DataFlow::Configuration {
-  GeneratorFlowConfig() { this = "GeneratorFlowConfig" }
+module TestConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source.asExpr().getStringValue() = "source" }
 
-  override predicate isSource(DataFlow::Node source) { source.asExpr().getStringValue() = "source" }
-
-  override predicate isSink(DataFlow::Node sink) {
+  predicate isSink(DataFlow::Node sink) {
     sink = any(DataFlow::CallNode call | call.getCalleeName() = "sink").getAnArgument()
   }
 }
+
+module TestFlow = DataFlow::Global<TestConfig>;
+
+class LegacyConfig extends DataFlow::Configuration {
+  LegacyConfig() { this = "GeneratorFlowConfig" }
+
+  override predicate isSource(DataFlow::Node source) { TestConfig::isSource(source) }
+
+  override predicate isSink(DataFlow::Node sink) { TestConfig::isSink(sink) }
+}
+
+import testUtilities.LegacyDataFlowDiff::DataFlowDiff<TestFlow, LegacyConfig>
+
+class Consistency extends ConsistencyConfiguration {
+  Consistency() { this = "Consistency" }
+
+  override DataFlow::Node getAnAlert() { TestFlow::flowTo(result) }
+}

javascript/ql/test/library-tests/Generators/generators.js

@@ -31,6 +31,26 @@
     sink(e); // NOT OK
   }
 
+  try {
+    gen4();
+  } catch (e) {
+    sink(e); // OK - exception is only thrown upon iteration
+  }
+
+  const iterator = gen4();
+  try {
+    for (let v of iterator) {
+      sink(v); // OK
+    }
+  } catch (e) {
+    sink(e); // NOT OK
+  }
+  try {
+    Array.from(iterator);
+  } catch (e) {
+    sink(e); // NOT OK
+  }
+
   function *delegating() {
     yield* delegate();
   }