QL code and tests for C#/C++/JavaScript.

javascript/ql/test/query-tests/Statements/UselessConditional/UselessConditional.js

@@ -0,0 +1,47 @@
+function getLastLine(input) {
+  var lines = [], nextLine;
+  while ((nextLine = readNextLine(input)))
+    lines.push(nextLine);
+  if (!lines)
+    throw new Error("No lines!");
+  return lines[lines.length-1];
+}
+
+function lookup(cache, k) {
+  var v;
+  return k in cache ? cache[k] : (v = new Entry(recompute())) && (cache[k] = v);
+}
+
+function test(a, b) {
+  if (!a && !b) {
+    if (a);
+    if (b);
+  }
+  if (!(a || b)) {
+    if (a);
+    if (b);
+  }
+
+  var x = new X();
+  if(x){}
+  if (new X()){}
+  if((x)){}
+  if(((x))){}
+  if ((new X())){}
+
+  x = 0n;
+  if (x) // NOT OK
+    ;
+}
+
+async function awaitFlow(){
+    var v;
+
+    if (y)
+        v = await f()
+
+    if (v) { // OK
+    }
+}
+
+// semmle-extractor-options: --experimental