JS: Add SatisfiesExpr

Author: asgerf

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

@@ -334,7 +334,8 @@ module SourceNode {
         astNode instanceof Templating::PipeRefExpr or
         astNode instanceof Templating::TemplateVarRefExpr or
         astNode instanceof StringLiteral or
-        astNode instanceof TypeAssertion
+        astNode instanceof TypeAssertion or
+        astNode instanceof SatisfiesExpr
       )
       or
       exists(VariableDeclarator decl |

javascript/ql/lib/semmle/javascript/internal/TypeResolution.qll

@@ -235,6 +235,8 @@ module TypeResolution {
     or
     value.(TypeAssertion).getTypeAnnotation() = type
     or
+    value.(SatisfiesExpr).getTypeAnnotation() = type
+    or
     exists(VarDecl decl |
       // ValueFlow::step is restricted to variables with at most one assignment. Allow the type annotation
       // of a variable to propagate to its uses, even if the variable has multiple assignments.

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

@@ -50,4 +50,5 @@
 | subtype.ts:19:13:19:15 | req | 'express'.Request |
 | typeCast.ts:4:16:4:35 | e as express.Request | 'express'.Request |
 | typeCast.ts:5:16:5:33 | <express.Request>e | 'express'.Request |
+| typeCast.ts:6:16:6:42 | e satis ... Request | 'express'.Request |
 | varAssignment.ts:4:9:4:11 | req | 'express'.Request |

javascript/ql/test/library-tests/UnderlyingTypes/typeCast.ts

@@ -3,5 +3,5 @@ import * as express from 'express';
 function t1(e) {
     var req1 = e as express.Request; // $ hasUnderlyingType='express'.Request
     var req2 = <express.Request>e; // $ hasUnderlyingType='express'.Request
-    var req3 = e satisfies express.Request;
+    var req3 = e satisfies express.Request; // $ hasUnderlyingType='express'.Request
 }