add support for the synchronous-promise library

Author: erik-krogh

javascript/change-notes/2021-06-18-promises.md

@@ -9,4 +9,5 @@ lgtm,codescanning
     [native-promise-only](https://npmjs.com/package/native-promise-only),
     [when](https://npmjs.com/package/when),
     [pinkie-promise](https://npmjs.com/package/pinkie-promise),
-    [pinkie](https://npmjs.com/package/pinkie)
+    [pinkie](https://npmjs.com/package/pinkie),
+    [synchronous-promise](https://npmjs.com/package/synchronous-promise)

javascript/ql/src/semmle/javascript/Promises.qll

@@ -87,6 +87,8 @@ private DataFlow::SourceNode getAPromiseObject() {
   result = DataFlow::moduleImport("pinkie-promise")
   or
   result = DataFlow::moduleImport("pinkie")
+  or
+  result = DataFlow::moduleMember("synchronous-promise", "SynchronousPromise")
 }
 
 /**

javascript/ql/test/library-tests/Promises/promises.js

@@ -135,4 +135,10 @@
   new Promise(function (resolve, reject) {
     resolve(data);
   });
-})();
+})();
+
+(function() {
+  import { SynchronousPromise } from 'synchronous-promise';
+  // is technically not a promise, but behaves like one.
+  var promise = SynchronousPromise.resolve(source);
+})();

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

@@ -43,6 +43,7 @@ test_ResolvedPromiseDefinition
 | promises.js:114:3:114:25 | Promise ... source) | promises.js:114:19:114:24 | source |
 | promises.js:119:3:119:25 | Promise ... source) | promises.js:119:19:119:24 | source |
 | promises.js:125:20:125:39 | when.resolve(source) | promises.js:125:33:125:38 | source |
+| promises.js:143:17:143:50 | Synchro ... source) | promises.js:143:44:143:49 | source |
 test_PromiseDefinition_getARejectHandler
 | flow.js:26:2:26:49 | new Pro ... ource)) | flow.js:26:69:26:80 | y => sink(y) |
 | flow.js:32:2:32:49 | new Pro ... ource)) | flow.js:32:57:32:68 | x => sink(x) |
@@ -442,3 +443,5 @@ typetrack
 | promises.js:125:20:125:39 | when.resolve(source) | promises.js:125:33:125:38 | source | store $PromiseResolveField$ |
 | promises.js:135:3:137:4 | new Pro ... );\\n  }) | promises.js:136:13:136:16 | data | copy $PromiseResolveField$ |
 | promises.js:135:3:137:4 | new Pro ... );\\n  }) | promises.js:136:13:136:16 | data | store $PromiseResolveField$ |
+| promises.js:143:17:143:50 | Synchro ... source) | promises.js:143:44:143:49 | source | copy $PromiseResolveField$ |
+| promises.js:143:17:143:50 | Synchro ... source) | promises.js:143:44:143:49 | source | store $PromiseResolveField$ |