Add result node test with SPURIOUS result

Author: owen-mc

go/ql/test/library-tests/semmle/go/dataflow/Nodes/ResultNode.expected

@@ -0,0 +1,9 @@
+| main.go:21:9:21:10 | 23 | Result node with index 0 |
+| main.go:21:13:21:14 | 42 | Result node with index 1 |
+| resultParameters.go:5:10:5:10 | 0 | Result node with index 0 |
+| resultParameters.go:9:10:9:10 | 1 | Result node with index 0 |
+| resultParameters.go:11:10:11:10 | 2 | Result node with index 0 |
+| resultParameters.go:13:9:13:9 | 3 | Result node with index 0 |
+| resultParameters.go:16:26:16:26 | implicit read of r | Result node with index 0 |
+| resultParameters.go:21:38:21:38 | implicit read of r | Result node with index 0 |
+| resultParameters.go:24:10:24:10 | 1 | Result node with index 0 |

go/ql/test/library-tests/semmle/go/dataflow/Nodes/ResultNode.ql

@@ -0,0 +1,9 @@
+/**
+ * @kind problem
+ * @id result-node
+ */
+
+import go
+
+from DataFlow::ResultNode r
+select r, "Result node with index " + r.getIndex()

go/ql/test/library-tests/semmle/go/dataflow/Nodes/ResultNode.qlref

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

go/ql/test/library-tests/semmle/go/dataflow/Nodes/main.go

@@ -18,5 +18,5 @@ func f() {
 }
 
 func test() (int, int) {
-	return 23, 42
+	return 23, 42 // $ Alert[result-node]
 }

go/ql/test/library-tests/semmle/go/dataflow/Nodes/resultParameters.go

@@ -0,0 +1,27 @@
+package main
+
+func multipleReturns(selector int) int {
+	if selector == 0 {
+		return 0 // $ Alert[result-node]
+	}
+	switch selector {
+	case 1:
+		return 1 // $ Alert[result-node]
+	case 2:
+		return 2 // $ Alert[result-node]
+	}
+	return 3 // $ Alert[result-node]
+}
+
+func resultParameter1() (r int) { // $ Alert[result-node] // implicit reads of result parameters are located at the result parameter declaration
+	r = 0
+	return
+}
+
+func resultParameter2(selector int) (r int) { // $ Alert[result-node] // implicit reads of result parameters are located at the result parameter declaration
+	r = 0
+	if selector == 1 {
+		return 1 // $ SPURIOUS: Alert[result-node]
+	}
+	return
+}