JS: Fix missing flow into rest pattern lvalue

javascript/ql/lib/semmle/javascript/dataflow/DataFlow.qll

@@ -1610,6 +1610,11 @@ module DataFlow {
       pred = TElementPatternNode(_, element) and
       succ = lvalueNodeInternal(element)
     )
+    or
+    exists(Expr rest |
+      pred = TRestPatternNode(_, rest) and
+      succ = lvalueNodeInternal(rest)
+    )
   }
 
   /**

javascript/ql/test/library-tests/GetALocalSource/rest-pattern.js

@@ -0,0 +1,15 @@
+function t1() {
+    const { ...rest } = source('t1.1');
+    rest; // $ getALocalSource=rest
+}
+
+function t2() {
+    const [ ...rest ] = source('t2.1');
+    rest; // $ getALocalSource=rest
+}
+
+function t3() {
+    const { p1, ...rest } = source('t3.1');
+    p1; // $ getALocalSource=p1
+    rest; // $ getALocalSource=rest
+}

javascript/ql/test/library-tests/GetALocalSource/test.expected

@@ -0,0 +1,4 @@
+| rest-pattern.js:3:5:3:8 | rest | rest |
+| rest-pattern.js:8:5:8:8 | rest | rest |
+| rest-pattern.js:13:5:13:6 | p1 | p1 |
+| rest-pattern.js:14:5:14:8 | rest | rest |

javascript/ql/test/library-tests/GetALocalSource/test.ql

@@ -0,0 +1,30 @@
+import javascript
+
+string nodeName(DataFlow::SourceNode node) {
+  result = node.getAstNode().(VarRef).getName()
+  or
+  result = node.getAstNode().(PropertyPattern).getName()
+  or
+  result = node.getAstNode().(PropAccess).getPropertyName()
+  or
+  exists(DataFlow::InvokeNode invoke |
+    node = invoke and
+    invoke.getCalleeName() = "source" and
+    result = invoke.getArgument(0).getStringValue()
+  )
+}
+
+bindingset[node1, node2]
+pragma[inline_late]
+predicate sameLine(DataFlow::Node node1, DataFlow::Node node2) {
+  node1.getLocation().getFile() = node2.getLocation().getFile() and
+  node1.getLocation().getStartLine() = node2.getLocation().getStartLine()
+}
+
+query predicate getALocalSource(DataFlow::Node node, string name) {
+  exists(DataFlow::SourceNode sn |
+    sn = node.getALocalSource() and
+    name = nodeName(sn) and
+    not sameLine(node, sn)
+  )
+}

javascript/ql/test/library-tests/GetALocalSource/test.qlref

@@ -0,0 +1,2 @@
+query: test.ql
+postprocess: utils/test/InlineExpectationsTestQuery.ql