Merge pull request #2237 from asger-semmle/typescript3.7-rc

TS: Add support for TypeScript 3.7

change-notes/1.23/analysis-javascript.md

@@ -12,7 +12,7 @@
 
 * The call graph has been improved to resolve method calls in more cases. This may produce more security alerts.
 
-* TypeScript 3.6 features are supported.
+* TypeScript 3.6 and 3.7 features are now supported.
 
 * Automatic classification of generated files has been improved, in particular files generated by Doxygen are now recognized.
 

javascript/extractor/lib/typescript/package.json

@@ -2,7 +2,7 @@
     "name": "typescript-parser-wrapper",
     "private": true,
     "dependencies": {
-        "typescript": "3.6.3"
+        "typescript": "^3.7.2"
     },
     "scripts": {
         "build": "tsc --project tsconfig.json",

javascript/extractor/lib/typescript/src/main.ts

@@ -126,7 +126,7 @@ function checkCycle(root: any) {
 function isBlacklistedProperty(k: string) {
     return k === "parent" || k === "pos" || k === "end"
         || k === "symbol" || k === "localSymbol"
-        || k === "flowNode" || k === "returnFlowNode"
+        || k === "flowNode" || k === "returnFlowNode" || k === "endFlowNode"
         || k === "nextContainer" || k === "locals"
         || k === "bindDiagnostics" || k === "bindSuggestionDiagnostics";
 }

javascript/extractor/lib/typescript/src/type_table.ts

@@ -597,7 +597,7 @@ export class TypeTable {
       let tupleType = tupleReference.target;
       let minLength = tupleType.minLength != null
           ? tupleType.minLength
-          : tupleReference.typeArguments.length;
+          : this.typeChecker.getTypeArguments(tupleReference).length;
       let hasRestElement = tupleType.hasRestElement ? 't' : 'f';
       let prefix = `tuple;${minLength};${hasRestElement}`;
       return this.makeTypeStringVectorFromTypeReferenceArguments(prefix, type);
@@ -714,11 +714,12 @@ export class TypeTable {
     // There can be an extra type argument at the end, denoting an explicit 'this' type argument.
     // We discard the extra argument in our model.
     let target = type.target;
-    if (type.typeArguments == null) return tag;
+    let typeArguments = this.typeChecker.getTypeArguments(type);
+    if (typeArguments == null) return tag;
     if (target.typeParameters != null) {
-      return this.makeTypeStringVector(tag, type.typeArguments, target.typeParameters.length);
+      return this.makeTypeStringVector(tag, typeArguments, target.typeParameters.length);
     } else {
-      return this.makeTypeStringVector(tag, type.typeArguments);
+      return this.makeTypeStringVector(tag, typeArguments);
     }
   }
 
@@ -992,7 +993,7 @@ export class TypeTable {
    * `T` is the type parameter declared on the `Promise` interface.
    */
   private getSelfType(type: ts.Type): ts.TypeReference {
-    if (isTypeReference(type) && type.typeArguments != null && type.typeArguments.length > 0) {
+    if (isTypeReference(type) && this.typeChecker.getTypeArguments(type).length > 0) {
       return type.target;
     }
     return null;
@@ -1181,8 +1182,9 @@ export class TypeTable {
     if (isTypeReference(type)) {
       // Note that this case also handles tuple types, since a tuple type is represented as
       // a reference to a synthetic generic interface.
-      if (type.typeArguments != null) {
-        type.typeArguments.forEach(callback);
+      let typeArguments = this.typeChecker.getTypeArguments(type);
+      if (typeArguments != null) {
+        typeArguments.forEach(callback);
       }
     } else if (type.flags & ts.TypeFlags.UnionOrIntersection) {
       (type as ts.UnionOrIntersectionType).types.forEach(callback);

javascript/extractor/lib/typescript/yarn.lock

@@ -225,9 +225,9 @@ tsutils@^2.12.1:
   dependencies:
     tslib "^1.8.1"
 
-typescript@3.6.3:
-  version "3.6.3"
-  resolved "typescript-3.6.3.tgz#fea942fabb20f7e1ca7164ff626f1a9f3f70b4da"
+typescript@^3.7.2:
+  version "3.7.2"
+  resolved "typescript-3.7.2.tgz"
 
 wrappy@1:
   version "1.0.2"

javascript/extractor/src/com/semmle/jcorn/CustomParser.java

@@ -7,6 +7,7 @@ import com.semmle.js.ast.AssignmentExpression;
 import com.semmle.js.ast.BlockStatement;
 import com.semmle.js.ast.CallExpression;
 import com.semmle.js.ast.CatchClause;
+import com.semmle.js.ast.Chainable;
 import com.semmle.js.ast.ClassExpression;
 import com.semmle.js.ast.ComprehensionBlock;
 import com.semmle.js.ast.ComprehensionExpression;
@@ -470,7 +471,8 @@ public class CustomParser extends FlowParser {
 
       Expression property = this.parsePropertyIdentifierOrIdentifier();
       MemberExpression node =
-          new MemberExpression(start, base, property, false, false, isOnOptionalChain(false, base));
+          new MemberExpression(
+              start, base, property, false, false, Chainable.isOnOptionalChain(false, base));
       return Pair.make(this.finishNode(node), true);
     } else if (this.eat(doubleDot)) {
       SourceLocation start = new SourceLocation(startLoc);

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -1520,10 +1520,6 @@ public class Parser {
     }
   }
 
-  protected boolean isOnOptionalChain(boolean optional, Expression base) {
-    return optional || base instanceof Chainable && ((Chainable) base).isOnOptionalChain();
-  }
-
   /**
    * Parse a single subscript {@code s}; if more subscripts could follow, return {@code Pair.make(s,
    * true}, otherwise return {@code Pair.make(s, false)}.
@@ -1544,7 +1540,7 @@ public class Parser {
               this.parseExpression(false, null),
               true,
               optional,
-              isOnOptionalChain(optional, base));
+              Chainable.isOnOptionalChain(optional, base));
       this.expect(TokenType.bracketR);
       return Pair.make(this.finishNode(node), true);
     } else if (!noCalls && this.eat(TokenType.parenL)) {
@@ -1572,10 +1568,10 @@ public class Parser {
               new ArrayList<>(),
               exprList,
               optional,
-              isOnOptionalChain(optional, base));
+              Chainable.isOnOptionalChain(optional, base));
       return Pair.make(this.finishNode(node), true);
     } else if (this.type == TokenType.backQuote) {
-      if (isOnOptionalChain(optional, base)) {
+      if (Chainable.isOnOptionalChain(optional, base)) {
         this.raise(base, "An optional chain may not be used in a tagged template expression.");
       }
       TaggedTemplateExpression node =
@@ -1590,7 +1586,7 @@ public class Parser {
               this.parseIdent(true),
               false,
               optional,
-              isOnOptionalChain(optional, base));
+              Chainable.isOnOptionalChain(optional, base));
       return Pair.make(this.finishNode(node), true);
     } else {
       return Pair.make(base, false);
@@ -1832,7 +1828,7 @@ public class Parser {
     Expression callee =
         this.parseSubscripts(this.parseExprAtom(null), innerStartPos, innerStartLoc, true);
 
-    if (isOnOptionalChain(false, callee))
+    if (Chainable.isOnOptionalChain(false, callee))
       this.raise(callee, "An optional chain may not be used in a `new` expression.");
 
     return parseNewArguments(startLoc, callee);
@@ -2314,7 +2310,7 @@ public class Parser {
       }
 
       if (node instanceof MemberExpression) {
-        if (isOnOptionalChain(false, (MemberExpression) node))
+        if (Chainable.isOnOptionalChain(false, (MemberExpression) node))
           this.raise(node, "Invalid left-hand side in assignment");
         if (!isBinding) return node;
       }

javascript/extractor/src/com/semmle/js/ast/Chainable.java

@@ -7,4 +7,14 @@ public interface Chainable {
 
   /** Is this on an optional chain? */
   abstract boolean isOnOptionalChain();
+
+  /**
+   * Returns true if a chainable node is on an optional chain.
+   *
+   * @param optional true if the node in question is itself optional (has the ?. token)
+   * @param base the calle or base of the optional access
+   */
+  public static boolean isOnOptionalChain(boolean optional, Expression base) {
+    return optional || base instanceof Chainable && ((Chainable) base).isOnOptionalChain();
+  }
 }

javascript/extractor/src/com/semmle/js/ast/DeclarationFlags.java

@@ -17,9 +17,10 @@ public class DeclarationFlags {
   public static final int protected_ = 1 << 6;
   public static final int optional = 1 << 7;
   public static final int definiteAssignmentAssertion = 1 << 8;
+  public static final int declareKeyword = 1 << 9;
 
   public static final int none = 0;
-  public static final int numberOfFlags = 9;
+  public static final int numberOfFlags = 10;
 
   public static final List<String> names =
       Arrays.asList(
@@ -31,7 +32,8 @@ public class DeclarationFlags {
           "private",
           "protected",
           "optional",
-          "definiteAssignmentAssertion");
+          "definiteAssignmentAssertion",
+          "declare");
 
   public static final List<String> relationNames =
       Arrays.asList(
@@ -43,7 +45,8 @@ public class DeclarationFlags {
           "hasPrivateKeyword",
           "hasProtectedKeyword",
           "isOptionalMember",
-          "hasDefiniteAssignmentAssertion");
+          "hasDefiniteAssignmentAssertion",
+          "hasDeclareKeyword");
 
   public static boolean isComputed(int flags) {
     return (flags & computed) != 0;
@@ -81,6 +84,10 @@ public class DeclarationFlags {
     return (flags & definiteAssignmentAssertion) != 0;
   }
 
+  public static boolean hasDeclareKeyword(int flags) {
+    return (flags & declareKeyword) != 0;
+  }
+
   /** Returns a mask with the computed bit set to the value of <tt>enable</tt>. */
   public static int getComputed(boolean enable) {
     return enable ? computed : 0;
@@ -128,6 +135,11 @@ public class DeclarationFlags {
     return enable ? definiteAssignmentAssertion : 0;
   }
 
+  /** Returns a mask with the declare keyword bit set to the value of <tt>enable</tt>. */
+  public static int getDeclareKeyword(boolean enable) {
+    return enable ? declareKeyword : 0;
+  }
+
   /** Returns true if the <tt>n</tt>th bit is set in <tt>flags</tt>. */
   public static boolean hasNthFlag(int flags, int n) {
     return (flags & (1 << n)) != 0;

javascript/extractor/src/com/semmle/js/ast/DefaultVisitor.java

@@ -34,13 +34,13 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.NonNullAssertion;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
@@ -634,7 +634,7 @@ public class DefaultVisitor<C, R> implements Visitor<C, R> {
   }
 
   @Override
-  public R visit(IsTypeExpr nd, C c) {
+  public R visit(PredicateTypeExpr nd, C c) {
     return visit((TypeExpression) nd, c);
   }
 

javascript/extractor/src/com/semmle/js/ast/MemberDefinition.java

@@ -75,6 +75,11 @@ public abstract class MemberDefinition<V extends Expression> extends Node {
     return DeclarationFlags.isReadonly(flags);
   }
 
+  /** Returns true if this has the <tt>declare</tt> modifier. */
+  public boolean hasDeclareKeyword() {
+    return DeclarationFlags.hasDeclareKeyword(flags);
+  }
+
   /**
    * Returns the expression denoting the name of the member, or {@code null} if this is a
    * call/construct signature.

javascript/extractor/src/com/semmle/js/ast/NodeCopier.java

@@ -30,13 +30,13 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.NonNullAssertion;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
@@ -717,8 +717,12 @@ public class NodeCopier implements Visitor<Void, INode> {
   }
 
   @Override
-  public INode visit(IsTypeExpr nd, Void c) {
-    return new IsTypeExpr(visit(nd.getLoc()), copy(nd.getLeft()), copy(nd.getRight()));
+  public INode visit(PredicateTypeExpr nd, Void c) {
+    return new PredicateTypeExpr(
+        visit(nd.getLoc()),
+        copy(nd.getExpression()),
+        copy(nd.getTypeExpr()),
+        nd.hasAssertsKeyword());
   }
 
   @Override

javascript/extractor/src/com/semmle/js/ast/Visitor.java

@@ -30,13 +30,13 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.NonNullAssertion;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
@@ -256,7 +256,7 @@ public interface Visitor<C, R> {
 
   public R visit(TypeofTypeExpr nd, C c);
 
-  public R visit(IsTypeExpr nd, C c);
+  public R visit(PredicateTypeExpr nd, C c);
 
   public R visit(InterfaceTypeExpr nd, C c);
 

javascript/extractor/src/com/semmle/js/extractor/ASTExtractor.java

@@ -125,13 +125,13 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.NonNullAssertion;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
@@ -1410,6 +1410,10 @@ public class ASTExtractor {
         }
       }
 
+      if (nd.hasDeclareKeyword()) {
+        trapwriter.addTuple("hasDeclareKeyword", methkey);
+      }
+
       return methkey;
     }
 
@@ -1707,10 +1711,13 @@ public class ASTExtractor {
     }
 
     @Override
-    public Label visit(IsTypeExpr nd, Context c) {
+    public Label visit(PredicateTypeExpr nd, Context c) {
       Label key = super.visit(nd, c);
-      visit(nd.getLeft(), key, 0, IdContext.varInTypeBind);
-      visit(nd.getRight(), key, 1, IdContext.typeBind);
+      visit(nd.getExpression(), key, 0, IdContext.varInTypeBind);
+      visit(nd.getTypeExpr(), key, 1, IdContext.typeBind);
+      if (nd.hasAssertsKeyword()) {
+        trapwriter.addTuple("hasAssertsKeyword", key);
+      }
       return key;
     }
 

javascript/extractor/src/com/semmle/js/extractor/ScopeManager.java

@@ -46,9 +46,9 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
 import com.semmle.ts.ast.UnionTypeExpr;
@@ -660,8 +660,8 @@ public class ScopeManager {
           }
 
           @Override
-          public Void visit(IsTypeExpr nd, Void c) {
-            return nd.getRight().accept(this, c);
+          public Void visit(PredicateTypeExpr nd, Void c) {
+            return nd.getTypeExpr().accept(this, c);
           }
 
           @Override

javascript/extractor/src/com/semmle/js/extractor/TypeExprKinds.java

@@ -16,11 +16,11 @@ import com.semmle.ts.ast.IndexedAccessTypeExpr;
 import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeParameter;
@@ -159,7 +159,7 @@ public class TypeExprKinds {
               }
 
               @Override
-              public Integer visit(IsTypeExpr nd, Void c) {
+              public Integer visit(PredicateTypeExpr nd, Void c) {
                 return isTypeExpr;
               }
 

javascript/extractor/src/com/semmle/js/parser/TypeScriptASTConverter.java

@@ -17,6 +17,7 @@ import com.semmle.js.ast.BlockStatement;
 import com.semmle.js.ast.BreakStatement;
 import com.semmle.js.ast.CallExpression;
 import com.semmle.js.ast.CatchClause;
+import com.semmle.js.ast.Chainable;
 import com.semmle.js.ast.ClassBody;
 import com.semmle.js.ast.ClassDeclaration;
 import com.semmle.js.ast.ClassExpression;
@@ -126,13 +127,13 @@ import com.semmle.ts.ast.InferTypeExpr;
 import com.semmle.ts.ast.InterfaceDeclaration;
 import com.semmle.ts.ast.InterfaceTypeExpr;
 import com.semmle.ts.ast.IntersectionTypeExpr;
-import com.semmle.ts.ast.IsTypeExpr;
 import com.semmle.ts.ast.KeywordTypeExpr;
 import com.semmle.ts.ast.MappedTypeExpr;
 import com.semmle.ts.ast.NamespaceDeclaration;
 import com.semmle.ts.ast.NonNullAssertion;
 import com.semmle.ts.ast.OptionalTypeExpr;
 import com.semmle.ts.ast.ParenthesizedTypeExpr;
+import com.semmle.ts.ast.PredicateTypeExpr;
 import com.semmle.ts.ast.RestTypeExpr;
 import com.semmle.ts.ast.TupleTypeExpr;
 import com.semmle.ts.ast.TypeAliasDeclaration;
@@ -877,7 +878,10 @@ public class TypeScriptASTConverter {
     }
     Expression callee = convertChild(node, "expression");
     List<ITypeExpression> typeArguments = convertChildrenAsTypes(node, "typeArguments");
-    CallExpression call = new CallExpression(loc, callee, typeArguments, arguments, false, false);
+    boolean optional = node.has("questionDotToken");
+    boolean onOptionalChain = Chainable.isOnOptionalChain(optional, callee);
+    CallExpression call =
+        new CallExpression(loc, callee, typeArguments, arguments, optional, onOptionalChain);
     attachResolvedSignature(call, node);
     return call;
   }
@@ -1108,7 +1112,9 @@ public class TypeScriptASTConverter {
       throws ParseError {
     Expression object = convertChild(node, "expression");
     Expression property = convertChild(node, "argumentExpression");
-    return new MemberExpression(loc, object, property, true, false, false);
+    boolean optional = node.has("questionDotToken");
+    boolean onOptionalChain = Chainable.isOnOptionalChain(optional, object);
+    return new MemberExpression(loc, object, property, true, optional, onOptionalChain);
   }
 
   private Node convertEmptyStatement(SourceLocation loc) {
@@ -1584,10 +1590,14 @@ public class TypeScriptASTConverter {
 
   private Node convertMetaProperty(JsonObject node, SourceLocation loc) throws ParseError {
     Position metaStart = loc.getStart();
-    String keywordKind = syntaxKinds.get(node.getAsJsonPrimitive("keywordToken").getAsInt() + "").getAsString();
+    String keywordKind =
+        syntaxKinds.get(node.getAsJsonPrimitive("keywordToken").getAsInt() + "").getAsString();
     String identifier = keywordKind.equals("ImportKeyword") ? "import" : "new";
     Position metaEnd =
-        new Position(metaStart.getLine(), metaStart.getColumn() + identifier.length(), metaStart.getOffset() + identifier.length());
+        new Position(
+            metaStart.getLine(),
+            metaStart.getColumn() + identifier.length(),
+            metaStart.getOffset() + identifier.length());
     SourceLocation metaLoc = new SourceLocation(identifier, metaStart, metaEnd);
     Identifier meta = new Identifier(metaLoc, identifier);
     return new MetaProperty(loc, meta, convertChild(node, "name"));
@@ -1967,8 +1977,11 @@ public class TypeScriptASTConverter {
 
   private Node convertPropertyAccessExpression(JsonObject node, SourceLocation loc)
       throws ParseError {
+    Expression base = convertChild(node, "expression");
+    boolean optional = node.has("questionDotToken");
+    boolean onOptionalChain = Chainable.isOnOptionalChain(optional, base);
     return new MemberExpression(
-        loc, convertChild(node, "expression"), convertChild(node, "name"), false, false, false);
+        loc, base, convertChild(node, "name"), false, optional, onOptionalChain);
   }
 
   private Node convertPropertyAssignment(JsonObject node, SourceLocation loc) throws ParseError {
@@ -1996,6 +2009,9 @@ public class TypeScriptASTConverter {
     if (node.get("exclamationToken") != null) {
       flags |= DeclarationFlags.definiteAssignmentAssertion;
     }
+    if (hasModifier(node, "DeclareKeyword")) {
+      flags |= DeclarationFlags.declareKeyword;
+    }
     FieldDefinition fieldDefinition =
         new FieldDefinition(
             loc,
@@ -2186,8 +2202,11 @@ public class TypeScriptASTConverter {
   }
 
   private Node convertTypePredicate(JsonObject node, SourceLocation loc) throws ParseError {
-    return new IsTypeExpr(
-        loc, convertChildAsType(node, "parameterName"), convertChildAsType(node, "type"));
+    return new PredicateTypeExpr(
+        loc,
+        convertChildAsType(node, "parameterName"),
+        convertChildAsType(node, "type"),
+        node.has("assertsModifier"));
   }
 
   private Node convertTypeReference(JsonObject node, SourceLocation loc) throws ParseError {

javascript/extractor/src/com/semmle/ts/ast/IsTypeExpr.java

@@ -1,32 +0,0 @@
-package com.semmle.ts.ast;
-
-import com.semmle.js.ast.SourceLocation;
-import com.semmle.js.ast.Visitor;
-
-/**
- * A type of form <tt>E is T</tt> where <tt>E</tt> is a parameter name or <tt>this</tt> and
- * <tt>T</tt> is a type.
- */
-public class IsTypeExpr extends TypeExpression {
-  private final ITypeExpression left; // Always Identifier or KeywordTypeExpr (in case of 'this')
-  private final ITypeExpression right;
-
-  public IsTypeExpr(SourceLocation loc, ITypeExpression left, ITypeExpression right) {
-    super("IsTypeExpr", loc);
-    this.left = left;
-    this.right = right;
-  }
-
-  public ITypeExpression getLeft() {
-    return left;
-  }
-
-  public ITypeExpression getRight() {
-    return right;
-  }
-
-  @Override
-  public <C, R> R accept(Visitor<C, R> v, C c) {
-    return v.visit(this, c);
-  }
-}

javascript/extractor/src/com/semmle/ts/ast/PredicateTypeExpr.java

@@ -0,0 +1,44 @@
+package com.semmle.ts.ast;
+
+import com.semmle.js.ast.SourceLocation;
+import com.semmle.js.ast.Visitor;
+
+/**
+ * A type of form <tt>E is T</tt>, <tt>asserts E is T</tt> or <tt>asserts E</tt> where <tt>E</tt> is
+ * a parameter name or <tt>this</tt> and <tt>T</tt> is a type.
+ */
+public class PredicateTypeExpr extends TypeExpression {
+  private final ITypeExpression expression;
+  private final ITypeExpression type;
+  private final boolean hasAssertsKeyword;
+
+  public PredicateTypeExpr(
+      SourceLocation loc,
+      ITypeExpression expression,
+      ITypeExpression type,
+      boolean hasAssertsKeyword) {
+    super("PredicateTypeExpr", loc);
+    this.expression = expression;
+    this.type = type;
+    this.hasAssertsKeyword = hasAssertsKeyword;
+  }
+
+  /** Returns the <tt>E</tt> in <tt>E is T</tt>. */
+  public ITypeExpression getExpression() {
+    return expression;
+  }
+
+  /** Returns the <tt>T</tt> in <tt>E is T</tt>. */
+  public ITypeExpression getTypeExpr() {
+    return type;
+  }
+
+  public boolean hasAssertsKeyword() {
+    return hasAssertsKeyword;
+  }
+
+  @Override
+  public <C, R> R accept(Visitor<C, R> v, C c) {
+    return v.visit(this, c);
+  }
+}

javascript/extractor/tests/ts/input/optionalChaining.ts

@@ -0,0 +1,3 @@
+base?.x.y;
+base?.(x).y;
+base?.[z].y;

javascript/extractor/tests/ts/output/trap/optionalChaining.ts.trap

@@ -0,0 +1,303 @@
+#10000=@"/optionalChaining.ts;sourcefile"
+files(#10000,"/optionalChaining.ts","optionalChaining","ts",0)
+#10001=@"/;folder"
+folders(#10001,"/","")
+containerparent(#10001,#10000)
+#10002=@"loc,{#10000},0,0,0,0"
+locations_default(#10002,#10000,0,0,0,0)
+hasLocation(#10000,#10002)
+#20000=@"global_scope"
+scopes(#20000,0)
+#20001=@"script;{#10000},1,1"
+#20002=*
+lines(#20002,#20001,"base?.x.y;","
+")
+#20003=@"loc,{#10000},1,1,1,10"
+locations_default(#20003,#10000,1,1,1,10)
+hasLocation(#20002,#20003)
+#20004=*
+lines(#20004,#20001,"base?.(x).y;","
+")
+#20005=@"loc,{#10000},2,1,2,12"
+locations_default(#20005,#10000,2,1,2,12)
+hasLocation(#20004,#20005)
+#20006=*
+lines(#20006,#20001,"base?.[z].y;","
+")
+#20007=@"loc,{#10000},3,1,3,12"
+locations_default(#20007,#10000,3,1,3,12)
+hasLocation(#20006,#20007)
+numlines(#20001,3,3,0)
+#20008=*
+tokeninfo(#20008,6,#20001,0,"base")
+#20009=@"loc,{#10000},1,1,1,4"
+locations_default(#20009,#10000,1,1,1,4)
+hasLocation(#20008,#20009)
+#20010=*
+tokeninfo(#20010,8,#20001,1,"?.")
+#20011=@"loc,{#10000},1,5,1,6"
+locations_default(#20011,#10000,1,5,1,6)
+hasLocation(#20010,#20011)
+#20012=*
+tokeninfo(#20012,6,#20001,2,"x")
+#20013=@"loc,{#10000},1,7,1,7"
+locations_default(#20013,#10000,1,7,1,7)
+hasLocation(#20012,#20013)
+#20014=*
+tokeninfo(#20014,8,#20001,3,".")
+#20015=@"loc,{#10000},1,8,1,8"
+locations_default(#20015,#10000,1,8,1,8)
+hasLocation(#20014,#20015)
+#20016=*
+tokeninfo(#20016,6,#20001,4,"y")
+#20017=@"loc,{#10000},1,9,1,9"
+locations_default(#20017,#10000,1,9,1,9)
+hasLocation(#20016,#20017)
+#20018=*
+tokeninfo(#20018,8,#20001,5,";")
+#20019=@"loc,{#10000},1,10,1,10"
+locations_default(#20019,#10000,1,10,1,10)
+hasLocation(#20018,#20019)
+#20020=*
+tokeninfo(#20020,6,#20001,6,"base")
+#20021=@"loc,{#10000},2,1,2,4"
+locations_default(#20021,#10000,2,1,2,4)
+hasLocation(#20020,#20021)
+#20022=*
+tokeninfo(#20022,8,#20001,7,"?.")
+#20023=@"loc,{#10000},2,5,2,6"
+locations_default(#20023,#10000,2,5,2,6)
+hasLocation(#20022,#20023)
+#20024=*
+tokeninfo(#20024,8,#20001,8,"(")
+#20025=@"loc,{#10000},2,7,2,7"
+locations_default(#20025,#10000,2,7,2,7)
+hasLocation(#20024,#20025)
+#20026=*
+tokeninfo(#20026,6,#20001,9,"x")
+#20027=@"loc,{#10000},2,8,2,8"
+locations_default(#20027,#10000,2,8,2,8)
+hasLocation(#20026,#20027)
+#20028=*
+tokeninfo(#20028,8,#20001,10,")")
+#20029=@"loc,{#10000},2,9,2,9"
+locations_default(#20029,#10000,2,9,2,9)
+hasLocation(#20028,#20029)
+#20030=*
+tokeninfo(#20030,8,#20001,11,".")
+#20031=@"loc,{#10000},2,10,2,10"
+locations_default(#20031,#10000,2,10,2,10)
+hasLocation(#20030,#20031)
+#20032=*
+tokeninfo(#20032,6,#20001,12,"y")
+#20033=@"loc,{#10000},2,11,2,11"
+locations_default(#20033,#10000,2,11,2,11)
+hasLocation(#20032,#20033)
+#20034=*
+tokeninfo(#20034,8,#20001,13,";")
+#20035=@"loc,{#10000},2,12,2,12"
+locations_default(#20035,#10000,2,12,2,12)
+hasLocation(#20034,#20035)
+#20036=*
+tokeninfo(#20036,6,#20001,14,"base")
+#20037=@"loc,{#10000},3,1,3,4"
+locations_default(#20037,#10000,3,1,3,4)
+hasLocation(#20036,#20037)
+#20038=*
+tokeninfo(#20038,8,#20001,15,"?.")
+#20039=@"loc,{#10000},3,5,3,6"
+locations_default(#20039,#10000,3,5,3,6)
+hasLocation(#20038,#20039)
+#20040=*
+tokeninfo(#20040,8,#20001,16,"[")
+#20041=@"loc,{#10000},3,7,3,7"
+locations_default(#20041,#10000,3,7,3,7)
+hasLocation(#20040,#20041)
+#20042=*
+tokeninfo(#20042,6,#20001,17,"z")
+#20043=@"loc,{#10000},3,8,3,8"
+locations_default(#20043,#10000,3,8,3,8)
+hasLocation(#20042,#20043)
+#20044=*
+tokeninfo(#20044,8,#20001,18,"]")
+#20045=@"loc,{#10000},3,9,3,9"
+locations_default(#20045,#10000,3,9,3,9)
+hasLocation(#20044,#20045)
+#20046=*
+tokeninfo(#20046,8,#20001,19,".")
+#20047=@"loc,{#10000},3,10,3,10"
+locations_default(#20047,#10000,3,10,3,10)
+hasLocation(#20046,#20047)
+#20048=*
+tokeninfo(#20048,6,#20001,20,"y")
+#20049=@"loc,{#10000},3,11,3,11"
+locations_default(#20049,#10000,3,11,3,11)
+hasLocation(#20048,#20049)
+#20050=*
+tokeninfo(#20050,8,#20001,21,";")
+#20051=@"loc,{#10000},3,12,3,12"
+locations_default(#20051,#10000,3,12,3,12)
+hasLocation(#20050,#20051)
+#20052=*
+tokeninfo(#20052,0,#20001,22,"")
+#20053=@"loc,{#10000},4,1,4,0"
+locations_default(#20053,#10000,4,1,4,0)
+hasLocation(#20052,#20053)
+toplevels(#20001,0)
+#20054=@"loc,{#10000},1,1,4,0"
+locations_default(#20054,#10000,1,1,4,0)
+hasLocation(#20001,#20054)
+#20055=*
+stmts(#20055,2,#20001,0,"base?.x.y;")
+hasLocation(#20055,#20003)
+stmtContainers(#20055,#20001)
+#20056=*
+exprs(#20056,14,#20055,0,"base?.x.y")
+#20057=@"loc,{#10000},1,1,1,9"
+locations_default(#20057,#10000,1,1,1,9)
+hasLocation(#20056,#20057)
+enclosingStmt(#20056,#20055)
+exprContainers(#20056,#20001)
+#20058=*
+exprs(#20058,14,#20056,0,"base?.x")
+#20059=@"loc,{#10000},1,1,1,7"
+locations_default(#20059,#10000,1,1,1,7)
+hasLocation(#20058,#20059)
+enclosingStmt(#20058,#20055)
+exprContainers(#20058,#20001)
+#20060=*
+exprs(#20060,79,#20058,0,"base")
+hasLocation(#20060,#20009)
+enclosingStmt(#20060,#20055)
+exprContainers(#20060,#20001)
+literals("base","base",#20060)
+#20061=@"var;{base};{#20000}"
+variables(#20061,"base",#20000)
+bind(#20060,#20061)
+#20062=*
+exprs(#20062,0,#20058,1,"x")
+hasLocation(#20062,#20013)
+enclosingStmt(#20062,#20055)
+exprContainers(#20062,#20001)
+literals("x","x",#20062)
+isOptionalChaining(#20058)
+#20063=*
+exprs(#20063,0,#20056,1,"y")
+hasLocation(#20063,#20017)
+enclosingStmt(#20063,#20055)
+exprContainers(#20063,#20001)
+literals("y","y",#20063)
+#20064=*
+stmts(#20064,2,#20001,1,"base?.(x).y;")
+hasLocation(#20064,#20005)
+stmtContainers(#20064,#20001)
+#20065=*
+exprs(#20065,14,#20064,0,"base?.(x).y")
+#20066=@"loc,{#10000},2,1,2,11"
+locations_default(#20066,#10000,2,1,2,11)
+hasLocation(#20065,#20066)
+enclosingStmt(#20065,#20064)
+exprContainers(#20065,#20001)
+#20067=*
+exprs(#20067,13,#20065,0,"base?.(x)")
+#20068=@"loc,{#10000},2,1,2,9"
+locations_default(#20068,#10000,2,1,2,9)
+hasLocation(#20067,#20068)
+enclosingStmt(#20067,#20064)
+exprContainers(#20067,#20001)
+#20069=*
+exprs(#20069,79,#20067,-1,"base")
+hasLocation(#20069,#20021)
+enclosingStmt(#20069,#20064)
+exprContainers(#20069,#20001)
+literals("base","base",#20069)
+bind(#20069,#20061)
+#20070=*
+exprs(#20070,79,#20067,0,"x")
+hasLocation(#20070,#20027)
+enclosingStmt(#20070,#20064)
+exprContainers(#20070,#20001)
+literals("x","x",#20070)
+#20071=@"var;{x};{#20000}"
+variables(#20071,"x",#20000)
+bind(#20070,#20071)
+isOptionalChaining(#20067)
+#20072=*
+exprs(#20072,0,#20065,1,"y")
+hasLocation(#20072,#20033)
+enclosingStmt(#20072,#20064)
+exprContainers(#20072,#20001)
+literals("y","y",#20072)
+#20073=*
+stmts(#20073,2,#20001,2,"base?.[z].y;")
+hasLocation(#20073,#20007)
+stmtContainers(#20073,#20001)
+#20074=*
+exprs(#20074,14,#20073,0,"base?.[z].y")
+#20075=@"loc,{#10000},3,1,3,11"
+locations_default(#20075,#10000,3,1,3,11)
+hasLocation(#20074,#20075)
+enclosingStmt(#20074,#20073)
+exprContainers(#20074,#20001)
+#20076=*
+exprs(#20076,15,#20074,0,"base?.[z]")
+#20077=@"loc,{#10000},3,1,3,9"
+locations_default(#20077,#10000,3,1,3,9)
+hasLocation(#20076,#20077)
+enclosingStmt(#20076,#20073)
+exprContainers(#20076,#20001)
+#20078=*
+exprs(#20078,79,#20076,0,"base")
+hasLocation(#20078,#20037)
+enclosingStmt(#20078,#20073)
+exprContainers(#20078,#20001)
+literals("base","base",#20078)
+bind(#20078,#20061)
+#20079=*
+exprs(#20079,79,#20076,1,"z")
+hasLocation(#20079,#20043)
+enclosingStmt(#20079,#20073)
+exprContainers(#20079,#20001)
+literals("z","z",#20079)
+#20080=@"var;{z};{#20000}"
+variables(#20080,"z",#20000)
+bind(#20079,#20080)
+isOptionalChaining(#20076)
+#20081=*
+exprs(#20081,0,#20074,1,"y")
+hasLocation(#20081,#20049)
+enclosingStmt(#20081,#20073)
+exprContainers(#20081,#20001)
+literals("y","y",#20081)
+#20082=*
+entry_cfg_node(#20082,#20001)
+#20083=@"loc,{#10000},1,1,1,0"
+locations_default(#20083,#10000,1,1,1,0)
+hasLocation(#20082,#20083)
+#20084=*
+exit_cfg_node(#20084,#20001)
+hasLocation(#20084,#20053)
+successor(#20073,#20078)
+successor(#20081,#20074)
+successor(#20079,#20076)
+successor(#20078,#20079)
+successor(#20076,#20081)
+successor(#20078,#20084)
+successor(#20074,#20084)
+successor(#20064,#20069)
+successor(#20072,#20065)
+successor(#20070,#20067)
+successor(#20069,#20070)
+successor(#20067,#20072)
+successor(#20069,#20073)
+successor(#20065,#20073)
+successor(#20055,#20060)
+successor(#20063,#20056)
+successor(#20062,#20058)
+successor(#20060,#20062)
+successor(#20058,#20063)
+successor(#20060,#20064)
+successor(#20056,#20064)
+successor(#20082,#20055)
+numlines(#10000,3,3,0)
+filetype(#10000,"typescript")

javascript/ql/src/semmle/javascript/Classes.qll

@@ -1059,6 +1059,12 @@ class FieldDeclaration extends MemberDeclaration, @field {
 
   /** Holds if this is a TypeScript field marked as definitely assigned with the `!` operator. */
   predicate hasDefiniteAssignmentAssertion() { hasDefiniteAssignmentAssertion(this) }
+
+  override predicate isAmbient() {
+    hasDeclareKeyword(this)
+    or
+    getParent().isAmbient()
+  }
 }
 
 /**

javascript/ql/src/semmle/javascript/TypeScript.qll

@@ -914,20 +914,49 @@ class TypeofTypeExpr extends @typeoftypeexpr, TypeExpr {
 }
 
 /**
- * A type of form `E is T` where `E` is a parameter name or `this`, and `T` is a type.
+ * A function return type that refines the type of one of its parameters or `this`.
  *
- * This can only occur as the return type of a function type.
+ * Examples:
+ * ```js
+ * function f(x): x is string {}
+ * function f(x): asserts x is string {}
+ * function f(x): asserts x {}
+ * ```
  */
-class IsTypeExpr extends @istypeexpr, TypeExpr {
+class PredicateTypeExpr extends @predicatetypeexpr, TypeExpr {
   /**
    * Gets the parameter name or `this` token `E` in `E is T`.
    */
   VarTypeAccess getParameterName() { result = this.getChildTypeExpr(0) }
 
   /**
-   * Gets the type `T` in `E is T`.
+   * Gets the type `T` in `E is T` or `asserts E is T`.
+   *
+   * Has no results for types of form `asserts E`.
    */
   TypeExpr getPredicateType() { result = this.getChildTypeExpr(1) }
+
+  /**
+   * Holds if this is a type of form `asserts E is T` or `asserts E`.
+   */
+  predicate hasAssertsKeyword() {
+    hasAssertsKeyword(this)
+  }
+}
+
+/**
+ * A function return type of form `x is T` or `asserts x is T`.
+ *
+ * Examples:
+ * ```js
+ * function f(x): x is string {}
+ * function f(x): asserts x is string {}
+ * ```
+ */
+class IsTypeExpr extends PredicateTypeExpr {
+  IsTypeExpr() {
+    exists(getPredicateType())
+  }
 }
 
 /**
@@ -966,15 +995,16 @@ class ReadonlyTypeExpr extends @readonlytypeexpr, TypeExpr {
  *
  * This can occur as
  * - part of the operand to a `typeof` type, or
- * - as the first operand to an `is` type.
+ * - as the first operand to a predicate type
  *
  * For example, it may occur as the `E` in these examples:
  * ```
  * var x : typeof E
  * function f(...) : E is T {}
+ * function f(...) : asserts E  {}
  * ```
  *
- * In the latter case, this may also refer to the pseudo-variable `this`.
+ * In the latter two cases, this may also refer to the pseudo-variable `this`.
  */
 class VarTypeAccess extends @vartypeaccess, TypeExpr { }
 

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -200,8 +200,8 @@ case @stmt.kind of
 
 isInstantiated(unique int decl: @namespacedeclaration ref);
 
-@declarablestmt = @declstmt | @namespacedeclaration | @classdeclstmt | @functiondeclstmt | @enumdeclaration | @externalmoduledeclaration | @globalaugmentationdeclaration;
-hasDeclareKeyword(unique int stmt: @declarablestmt ref);
+@declarablenode = @declstmt | @namespacedeclaration | @classdeclstmt | @functiondeclstmt | @enumdeclaration | @externalmoduledeclaration | @globalaugmentationdeclaration | @field;
+hasDeclareKeyword(unique int stmt: @declarablenode ref);
 
 isForAwaitOf(unique int forof: @forofstmt ref);
 
@@ -559,7 +559,7 @@ case @typeexpr.kind of
 | 17 = @localvartypeaccess
 | 18 = @qualifiedvartypeaccess
 | 19 = @thisvartypeaccess
-| 20 = @istypeexpr
+| 20 = @predicatetypeexpr
 | 21 = @interfacetypeexpr
 | 22 = @typeparameter
 | 23 = @plainfunctiontypeexpr
@@ -637,6 +637,8 @@ case @type.kind of
 @unionorintersectiontype = @uniontype | @intersectiontype;
 @typevariabletype = @canonicaltypevariabletype | @lexicaltypevariabletype;
 
+hasAssertsKeyword(int node: @predicatetypeexpr ref);
+
 @typed_ast_node = @expr | @typeexpr | @function;
 ast_node_type(
   unique int node: @typed_ast_node ref, 

javascript/ql/src/semmlecode.javascript.dbscheme.stats

@@ -850,7 +850,7 @@
 <v>20</v>
 </e>
 <e>
-<k>@istypeexpr</k>
+<k>@predicatetypeexpr</k>
 <v>86</v>
 </e>
 <e>
@@ -7918,6 +7918,17 @@
 <dependencies/>
 </relation>
 <relation>
+<name>hasAssertsKeyword</name>
+<cardinality>66</cardinality>
+<columnsizes>
+<e>
+<k>node</k>
+<v>66</v>
+</e>
+</columnsizes>
+<dependencies/>
+</relation>
+<relation>
 <name>isAbstractMember</name>
 <cardinality>66</cardinality>
 <columnsizes>

javascript/ql/test/library-tests/Flow/AbstractValues.expected

@@ -208,6 +208,8 @@
 | nodeJsLib.js:1:18:1:43 | instance of function nodeJsModule |
 | nodeJsLib.js:3:15:3:37 | function nodeJsFoo |
 | nodeJsLib.js:3:15:3:37 | instance of function nodeJsFoo |
+| nullish-coalescing-op.ts:1:1:3:1 | function test |
+| nullish-coalescing-op.ts:1:1:3:1 | instance of function test |
 | o.js:1:1:2:0 | exports object of module o |
 | o.js:1:1:2:0 | module object of module o |
 | objlit.js:1:14:1:15 | object literal |

javascript/ql/test/library-tests/Flow/abseval.expected

@@ -204,6 +204,8 @@
 | nodeJsClient.js:5:5:5:6 | x2 | nodeJsClient.js:5:10:5:15 | es.foo | esLib.js:3:8:3:24 | function foo |
 | nodeJsClient.js:5:5:5:6 | x2 | nodeJsClient.js:5:10:5:15 | es.foo | file://:0:0:0:0 | indefinite value (call) |
 | nodeJsClient.js:5:5:5:6 | x2 | nodeJsClient.js:5:10:5:15 | es.foo | file://:0:0:0:0 | indefinite value (heap) |
+| nullish-coalescing-op.ts:2:7:2:7 | y | nullish-coalescing-op.ts:2:11:2:18 | x ?? 0.5 | file://:0:0:0:0 | indefinite value (call) |
+| nullish-coalescing-op.ts:2:7:2:7 | y | nullish-coalescing-op.ts:2:11:2:18 | x ?? 0.5 | file://:0:0:0:0 | non-zero value |
 | objlit.js:1:5:1:5 | A | objlit.js:1:9:1:15 | A \|\| {} | file://:0:0:0:0 | indefinite value (global) |
 | objlit.js:1:5:1:5 | A | objlit.js:1:9:1:15 | A \|\| {} | objlit.js:1:14:1:15 | object literal |
 | objlit.js:7:5:7:5 | B | objlit.js:7:9:7:10 | {} | objlit.js:7:9:7:10 | object literal |

javascript/ql/test/library-tests/Flow/getAPrototype.expected

@@ -40,6 +40,7 @@
 | nestedImport.js:9:1:12:1 | instance of function tst | nestedImport.js:9:1:12:1 | instance of function tst |
 | nodeJsLib.js:1:18:1:43 | instance of function nodeJsModule | nodeJsLib.js:1:18:1:43 | instance of function nodeJsModule |
 | nodeJsLib.js:3:15:3:37 | instance of function nodeJsFoo | nodeJsLib.js:3:15:3:37 | instance of function nodeJsFoo |
+| nullish-coalescing-op.ts:1:1:3:1 | instance of function test | nullish-coalescing-op.ts:1:1:3:1 | instance of function test |
 | objlit.js:2:9:2:21 | instance of anonymous function | objlit.js:2:9:2:21 | instance of anonymous function |
 | objlit.js:4:8:4:20 | instance of method baz | objlit.js:4:8:4:20 | instance of method baz |
 | objlit.js:10:2:12:1 | instance of anonymous function | objlit.js:10:2:12:1 | instance of anonymous function |

javascript/ql/test/library-tests/Flow/nullish-coalescing-op.ts

@@ -0,0 +1,3 @@
+function test(x) {
+  let y = x ?? 0.5;
+}

javascript/ql/test/library-tests/Flow/types.expected

@@ -113,6 +113,7 @@
 | nodeJsClient.js:2:5:2:6 | es | nodeJsClient.js:2:10:2:27 | require('./esLib') | boolean, class, date, function, null, number, object, regular expression,string or undefined |
 | nodeJsClient.js:4:5:4:6 | x1 | nodeJsClient.js:4:10:4:15 | nj.foo | boolean, class, date, function, null, number, object, regular expression,string or undefined |
 | nodeJsClient.js:5:5:5:6 | x2 | nodeJsClient.js:5:10:5:15 | es.foo | boolean, class, date, function, null, number, object, regular expression,string or undefined |
+| nullish-coalescing-op.ts:2:7:2:7 | y | nullish-coalescing-op.ts:2:11:2:18 | x ?? 0.5 | boolean, class, date, function, null, number, object, regular expression,string or undefined |
 | objlit.js:1:5:1:5 | A | objlit.js:1:9:1:15 | A \|\| {} | boolean, class, date, function, null, number, object, regular expression,string or undefined |
 | objlit.js:7:5:7:5 | B | objlit.js:7:9:7:10 | {} | object |
 | objlit.js:14:5:14:6 | x1 | objlit.js:14:10:14:10 | A | boolean, class, date, function, null, number, object, regular expression,string or undefined |

javascript/ql/test/library-tests/OptionalChaining/OptionalChainRoot.expected

@@ -1,7 +1,25 @@
+| short-circuiting-typescript.ts:3:5:3:18 | x?.(o1 = null) | short-circuiting-typescript.ts:3:5:3:18 | x?.(o1 = null) |
+| short-circuiting-typescript.ts:7:5:7:18 | x?.[o2 = null] | short-circuiting-typescript.ts:7:5:7:18 | x?.[o2 = null] |
+| short-circuiting-typescript.ts:12:5:12:31 | x?.[o3  ... = null) | short-circuiting-typescript.ts:12:5:12:18 | x?.[o3 = null] |
+| short-circuiting-typescript.ts:12:5:12:31 | x?.[o3  ... = null) | short-circuiting-typescript.ts:12:5:12:31 | x?.[o3  ... = null) |
 | short-circuiting.js:3:5:3:18 | x?.(o1 = null) | short-circuiting.js:3:5:3:18 | x?.(o1 = null) |
 | short-circuiting.js:7:5:7:18 | x?.[o2 = null] | short-circuiting.js:7:5:7:18 | x?.[o2 = null] |
 | short-circuiting.js:12:5:12:31 | x?.[o3  ... = null) | short-circuiting.js:12:5:12:18 | x?.[o3 = null] |
 | short-circuiting.js:12:5:12:31 | x?.[o3  ... = null) | short-circuiting.js:12:5:12:31 | x?.[o3  ... = null) |
+| tst-typescript.ts:2:1:2:6 | a?.b.c | tst-typescript.ts:2:1:2:4 | a?.b |
+| tst-typescript.ts:3:1:3:6 | a.b?.c | tst-typescript.ts:3:1:3:6 | a.b?.c |
+| tst-typescript.ts:4:1:4:7 | a?.b?.c | tst-typescript.ts:4:1:4:4 | a?.b |
+| tst-typescript.ts:4:1:4:7 | a?.b?.c | tst-typescript.ts:4:1:4:7 | a?.b?.c |
+| tst-typescript.ts:7:1:7:7 | f?.()() | tst-typescript.ts:7:1:7:5 | f?.() |
+| tst-typescript.ts:8:1:8:7 | f()?.() | tst-typescript.ts:8:1:8:7 | f()?.() |
+| tst-typescript.ts:9:1:9:9 | f?.()?.() | tst-typescript.ts:9:1:9:5 | f?.() |
+| tst-typescript.ts:9:1:9:9 | f?.()?.() | tst-typescript.ts:9:1:9:9 | f?.()?.() |
+| tst-typescript.ts:12:1:12:8 | a?.m().b | tst-typescript.ts:12:1:12:4 | a?.m |
+| tst-typescript.ts:13:1:13:9 | a.m?.().b | tst-typescript.ts:13:1:13:7 | a.m?.() |
+| tst-typescript.ts:14:1:14:8 | a.m()?.b | tst-typescript.ts:14:1:14:8 | a.m()?.b |
+| tst-typescript.ts:15:1:15:11 | a?.m?.()?.b | tst-typescript.ts:15:1:15:4 | a?.m |
+| tst-typescript.ts:15:1:15:11 | a?.m?.()?.b | tst-typescript.ts:15:1:15:8 | a?.m?.() |
+| tst-typescript.ts:15:1:15:11 | a?.m?.()?.b | tst-typescript.ts:15:1:15:11 | a?.m?.()?.b |
 | tst.js:2:1:2:6 | a?.b.c | tst.js:2:1:2:4 | a?.b |
 | tst.js:3:1:3:6 | a.b?.c | tst.js:3:1:3:6 | a.b?.c |
 | tst.js:4:1:4:7 | a?.b?.c | tst.js:4:1:4:4 | a?.b |

javascript/ql/test/library-tests/OptionalChaining/OptionalUse.expected

@@ -1,7 +1,25 @@
+| short-circuiting-typescript.ts:3:5:3:18 | x?.(o1 = null) |
+| short-circuiting-typescript.ts:7:5:7:18 | x?.[o2 = null] |
+| short-circuiting-typescript.ts:12:5:12:18 | x?.[o3 = null] |
+| short-circuiting-typescript.ts:12:5:12:31 | x?.[o3  ... = null) |
 | short-circuiting.js:3:5:3:18 | x?.(o1 = null) |
 | short-circuiting.js:7:5:7:18 | x?.[o2 = null] |
 | short-circuiting.js:12:5:12:18 | x?.[o3 = null] |
 | short-circuiting.js:12:5:12:31 | x?.[o3  ... = null) |
+| tst-typescript.ts:2:1:2:4 | a?.b |
+| tst-typescript.ts:3:1:3:6 | a.b?.c |
+| tst-typescript.ts:4:1:4:4 | a?.b |
+| tst-typescript.ts:4:1:4:7 | a?.b?.c |
+| tst-typescript.ts:7:1:7:5 | f?.() |
+| tst-typescript.ts:8:1:8:7 | f()?.() |
+| tst-typescript.ts:9:1:9:5 | f?.() |
+| tst-typescript.ts:9:1:9:9 | f?.()?.() |
+| tst-typescript.ts:12:1:12:4 | a?.m |
+| tst-typescript.ts:13:1:13:7 | a.m?.() |
+| tst-typescript.ts:14:1:14:8 | a.m()?.b |
+| tst-typescript.ts:15:1:15:4 | a?.m |
+| tst-typescript.ts:15:1:15:8 | a?.m?.() |
+| tst-typescript.ts:15:1:15:11 | a?.m?.()?.b |
 | tst.js:2:1:2:4 | a?.b |
 | tst.js:3:1:3:6 | a.b?.c |
 | tst.js:4:1:4:4 | a?.b |

javascript/ql/test/library-tests/OptionalChaining/ShortCircuiting.expected

@@ -1,3 +1,11 @@
+| short-circuiting-typescript.ts:4:10:4:11 | o1 | file://:0:0:0:0 | null |
+| short-circuiting-typescript.ts:4:10:4:11 | o1 | short-circuiting-typescript.ts:2:14:2:15 | object literal |
+| short-circuiting-typescript.ts:8:10:8:11 | o2 | file://:0:0:0:0 | null |
+| short-circuiting-typescript.ts:8:10:8:11 | o2 | short-circuiting-typescript.ts:6:14:6:15 | object literal |
+| short-circuiting-typescript.ts:13:10:13:11 | o3 | file://:0:0:0:0 | null |
+| short-circuiting-typescript.ts:13:10:13:11 | o3 | short-circuiting-typescript.ts:10:14:10:15 | object literal |
+| short-circuiting-typescript.ts:14:10:14:11 | o4 | file://:0:0:0:0 | null |
+| short-circuiting-typescript.ts:14:10:14:11 | o4 | short-circuiting-typescript.ts:11:14:11:15 | object literal |
 | short-circuiting.js:4:10:4:11 | o1 | file://:0:0:0:0 | null |
 | short-circuiting.js:4:10:4:11 | o1 | short-circuiting.js:2:14:2:15 | object literal |
 | short-circuiting.js:8:10:8:11 | o2 | file://:0:0:0:0 | null |

javascript/ql/test/library-tests/OptionalChaining/ShortCirtuiting.expected

@@ -1,8 +0,0 @@
-| short-circuiting.js:4:10:4:11 | o1 | file://:0:0:0:0 | null |
-| short-circuiting.js:4:10:4:11 | o1 | short-circuiting.js:2:14:2:15 | object literal |
-| short-circuiting.js:8:10:8:11 | o2 | file://:0:0:0:0 | null |
-| short-circuiting.js:8:10:8:11 | o2 | short-circuiting.js:6:14:6:15 | object literal |
-| short-circuiting.js:13:10:13:11 | o3 | file://:0:0:0:0 | null |
-| short-circuiting.js:13:10:13:11 | o3 | short-circuiting.js:10:14:10:15 | object literal |
-| short-circuiting.js:14:10:14:11 | o4 | file://:0:0:0:0 | null |
-| short-circuiting.js:14:10:14:11 | o4 | short-circuiting.js:11:14:11:15 | object literal |

javascript/ql/test/library-tests/OptionalChaining/ShortCirtuiting.ql

@@ -1,7 +0,0 @@
-import javascript
-
-from CallExpr c, Expr arg
-where
-  c.getCalleeName() = "DUMP" and
-  arg = c.getArgument(0)
-select arg, arg.analyze().getAValue()

javascript/ql/test/library-tests/OptionalChaining/short-circuiting-typescript.ts

@@ -0,0 +1,15 @@
+(function() {
+    var o1 = {};
+    x?.(o1 = null);
+    DUMP(o1);
+
+    var o2 = {};
+    x?.[o2 = null];
+    DUMP(o2);
+
+    var o3 = {},
+        o4 = {};
+    x?.[o3 = null]?.(o4 = null);
+    DUMP(o3);
+    DUMP(o4);
+});

javascript/ql/test/library-tests/OptionalChaining/tst-typescript.ts

@@ -0,0 +1,15 @@
+a.b.c;
+a?.b.c;
+a.b?.c;
+a?.b?.c;
+
+f()();
+f?.()();
+f()?.();
+f?.()?.();
+
+a.m().b;
+a?.m().b;
+a.m?.().b;
+a.m()?.b;
+a?.m?.()?.b;

javascript/ql/test/library-tests/TypeScript/DeclareInClass/test.expected

@@ -0,0 +1 @@
+| tst.ts:2:5:2:22 | declare x: number; | true |

javascript/ql/test/library-tests/TypeScript/DeclareInClass/test.ql

@@ -0,0 +1,5 @@
+import javascript
+
+from FieldDeclaration f, boolean ambient
+where if f.isAmbient() then ambient = true else ambient = false
+select f, ambient

javascript/ql/test/library-tests/TypeScript/DeclareInClass/tst.ts

@@ -0,0 +1,3 @@
+class C {
+    declare x: number;
+}

javascript/ql/test/library-tests/TypeScript/PromiseType/PromiseType.expected

@@ -1,10 +1,8 @@
 | p1 | MyPromise<string> | string |
 | p2 | MyPromise<any> | any |
 | p3 | Promise<string> | string |
-| p4 | PromiseLike<string> | string |
 | p5 | PromiseLike<string> | string |
 | p6 | Thenable<string> | string |
-| p7 | Thenable<string> | string |
 | p8 | ThenPromise<string> | string |
 | p9 | JQueryPromise<string> | string |
 | p10 | JQueryGenericPromise<string> | string |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/IsTypeExpr.qll

@@ -1,5 +0,0 @@
-import javascript
-
-query predicate test_IsTypeExpr(IsTypeExpr type, VarTypeAccess res0, TypeExpr res1) {
-  res0 = type.getParameterName() and res1 = type.getPredicateType()
-}

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/PredicateTypeExpr.qll

@@ -0,0 +1,13 @@
+import javascript
+
+query predicate test_IsTypeExpr(IsTypeExpr type, VarTypeAccess res0, TypeExpr res1) {
+  res0 = type.getParameterName() and res1 = type.getPredicateType()
+}
+
+query predicate test_PredicateTypeExpr(PredicateTypeExpr type, VarTypeAccess res0) {
+  res0 = type.getParameterName()
+}
+
+query predicate test_hasAssertsKeyword(PredicateTypeExpr type) {
+  type.hasAssertsKeyword()
+}

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/tests.expected

@@ -105,6 +105,9 @@ test_VariableTypes
 | tst.ts:135:5:135:24 | tupleWithRestElement | tupleWithRestElement | tst.ts:135:27:135:47 | [number ... ring[]] |
 | tst.ts:136:5:136:36 | tupleWi ... lements | tupleWithOptionalAndRestElements | tst.ts:136:39:136:68 | [number ... mber[]] |
 | tst.ts:137:5:137:15 | unknownType | unknownType | tst.ts:137:18:137:24 | unknown |
+| tst.ts:142:17:142:25 | condition | condition | tst.ts:142:28:142:30 | any |
+| tst.ts:142:33:142:35 | msg | msg | tst.ts:142:39:142:44 | string |
+| tst.ts:148:25:148:27 | val | val | tst.ts:148:30:148:32 | any |
 test_QualifiedTypeAccess
 | tst.ts:63:19:63:21 | N.I | tst.ts:63:19:63:19 | N | tst.ts:63:21:63:21 | I |
 | tst.ts:64:20:64:24 | N.M.I | tst.ts:64:20:64:22 | N.M | tst.ts:64:24:64:24 | I |
@@ -148,6 +151,17 @@ test_IsTypeExpr
 | tst.ts:76:21:76:32 | that is Leaf | tst.ts:76:21:76:24 | that | tst.ts:76:29:76:32 | Leaf |
 | tst.ts:80:36:80:55 | x is Generic<Leaf[]> | tst.ts:80:36:80:36 | x | tst.ts:80:41:80:55 | Generic<Leaf[]> |
 | tst.ts:81:38:81:50 | x is typeof x | tst.ts:81:38:81:38 | x | tst.ts:81:43:81:50 | typeof x |
+| tst.ts:148:36:148:56 | asserts ...  string | tst.ts:148:44:148:46 | val | tst.ts:148:51:148:56 | string |
+test_PredicateTypeExpr
+| tst.ts:75:17:75:28 | this is Leaf | tst.ts:75:17:75:20 | this |
+| tst.ts:76:21:76:32 | that is Leaf | tst.ts:76:21:76:24 | that |
+| tst.ts:80:36:80:55 | x is Generic<Leaf[]> | tst.ts:80:36:80:36 | x |
+| tst.ts:81:38:81:50 | x is typeof x | tst.ts:81:38:81:38 | x |
+| tst.ts:142:48:142:64 | asserts condition | tst.ts:142:56:142:64 | condition |
+| tst.ts:148:36:148:56 | asserts ...  string | tst.ts:148:44:148:46 | val |
+test_hasAssertsKeyword
+| tst.ts:142:48:142:64 | asserts condition |
+| tst.ts:148:36:148:56 | asserts ...  string |
 test_ThisParameterTypes
 | function hasThisParam | tst.ts:116:29:116:32 | void |
 | method hasThisParam of interface InterfaceWithThisParam | tst.ts:119:22:119:43 | Interfa ... isParam |
@@ -254,6 +268,8 @@ test_ReturnTypes
 | tst.ts:94:1:94:37 | functio ... rn x; } | function f1 | tst.ts:94:23:94:23 | S |
 | tst.ts:95:1:95:53 | functio ... x,y]; } | function f2 | tst.ts:95:31:95:35 | [S,T] |
 | tst.ts:96:1:96:52 | functio ... rn x; } | function f3 | tst.ts:96:38:96:38 | S |
+| tst.ts:142:1:146:1 | functio ... )\\n  }\\n} | function assert | tst.ts:142:48:142:64 | asserts condition |
+| tst.ts:148:1:152:1 | functio ... ;\\n  }\\n} | function assertIsString | tst.ts:148:36:148:56 | asserts ...  string |
 test_KeyofTypeExpr
 | tst.ts:49:16:49:30 | keyof Interface | tst.ts:49:22:49:30 | Interface |
 | tst.ts:113:26:113:35 | keyof Node | tst.ts:113:32:113:35 | Node |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/tests.ql

@@ -11,7 +11,7 @@ import GenericTypeExpr
 import IntersectionTypeExpr
 import FunctionTypeReturns
 import InterfaceTypeExpr
-import IsTypeExpr
+import PredicateTypeExpr
 import ThisParameterTypes
 import ChildIndex
 import TypeArguments

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/tst.ts

@@ -138,3 +138,15 @@ let unknownType: unknown;
 
 let taggedTemplateLiteralTypeArg1 = someTag<number>`Hello`;
 let taggedTemplateLiteralTypeArg2 = someTag<number, string>`Hello`;
+
+function assert(condition: any, msg?: string): asserts condition {
+  if (!condition) {
+      throw new AssertionError(msg)
+  }
+}
+
+function assertIsString(val: any): asserts val is string {
+  if (typeof val !== "string") {
+      throw new AssertionError("Not a string!");
+  }
+}

javascript/ql/test/library-tests/TypeScript/Types/GetExprType.expected

@@ -93,6 +93,30 @@
 | tst.ts:43:28:43:30 | foo | "foo" |
 | tst.ts:43:33:43:37 | "foo" | "foo" |
 | type_alias.ts:3:5:3:5 | b | boolean |
+| type_alias.ts:7:5:7:5 | c | ValueOrArray<number> |
+| type_alias.ts:14:9:14:32 | [proper ... ]: Json | any |
+| type_alias.ts:14:10:14:17 | property | string |
+| type_alias.ts:17:5:17:8 | json | Json |
+| type_alias.ts:21:18:21:35 | [key: string]: any | any |
+| type_alias.ts:21:19:21:21 | key | string |
+| type_alias.ts:23:7:23:12 | myNode | VirtualNode |
+| type_alias.ts:24:5:27:5 | ["div", ... ]\\n    ] | VirtualNode |
+| type_alias.ts:24:6:24:10 | "div" | "div" |
+| type_alias.ts:24:13:24:28 | { id: "parent" } | string \| { [key: string]: any; } |
+| type_alias.ts:24:15:24:16 | id | string |
+| type_alias.ts:24:19:24:26 | "parent" | "parent" |
+| type_alias.ts:25:9:25:61 | ["div", ... child"] | VirtualNode |
+| type_alias.ts:25:10:25:14 | "div" | "div" |
+| type_alias.ts:25:17:25:37 | { id: " ... hild" } | string \| { [key: string]: any; } |
+| type_alias.ts:25:19:25:20 | id | string |
+| type_alias.ts:25:23:25:35 | "first-child" | "first-child" |
+| type_alias.ts:25:40:25:60 | "I'm th ...  child" | "I'm the first child" |
+| type_alias.ts:26:9:26:63 | ["div", ... child"] | VirtualNode |
+| type_alias.ts:26:10:26:14 | "div" | "div" |
+| type_alias.ts:26:17:26:38 | { id: " ... hild" } | string \| { [key: string]: any; } |
+| type_alias.ts:26:19:26:20 | id | string |
+| type_alias.ts:26:23:26:36 | "second-child" | "second-child" |
+| type_alias.ts:26:41:26:62 | "I'm th ...  child" | "I'm the second child" |
 | type_definition_objects.ts:1:13:1:17 | dummy | typeof dummy.ts |
 | type_definition_objects.ts:1:24:1:32 | "./dummy" | any |
 | type_definition_objects.ts:3:14:3:14 | C | C |
@@ -115,4 +139,4 @@
 | type_definitions.ts:16:5:16:9 | color | Color |
 | type_definitions.ts:18:6:18:22 | EnumWithOneMember | EnumWithOneMember |
 | type_definitions.ts:19:5:19:5 | e | EnumWithOneMember |
-| type_definitions.ts:22:5:22:23 | aliasForNumberArray | number[] |
+| type_definitions.ts:22:5:22:23 | aliasForNumberArray | Alias<number> |

javascript/ql/test/library-tests/TypeScript/Types/GetTypeDefinitionType.expected

@@ -1,8 +1,11 @@
 | type_alias.ts:1:1:1:17 | type B = boolean; | boolean |
+| type_alias.ts:5:1:5:50 | type Va ... ay<T>>; | ValueOrArray<T> |
+| type_alias.ts:9:1:15:13 | type Js ... Json[]; | Json |
+| type_alias.ts:19:1:21:57 | type Vi ... ode[]]; | VirtualNode |
 | type_definition_objects.ts:3:8:3:17 | class C {} | C |
 | type_definition_objects.ts:6:8:6:16 | enum E {} | E |
 | type_definitions.ts:3:1:5:1 | interfa ... x: S;\\n} | I<S> |
 | type_definitions.ts:8:1:10:1 | class C ...  x: T\\n} | C<T> |
 | type_definitions.ts:13:1:15:1 | enum Co ...  blue\\n} | Color |
 | type_definitions.ts:18:1:18:33 | enum En ... ember } | EnumWithOneMember |
-| type_definitions.ts:21:1:21:20 | type Alias<T> = T[]; | T[] |
+| type_definitions.ts:21:1:21:20 | type Alias<T> = T[]; | Alias<T> |

javascript/ql/test/library-tests/TypeScript/Types/GetTypeExprType.expected

@@ -57,20 +57,56 @@
 | tst.ts:37:17:37:18 | [] | [] |
 | tst.ts:38:27:38:47 | [number ... ring[]] | [number, ...string[]] |
 | tst.ts:38:28:38:33 | number | number |
-| tst.ts:38:36:38:46 | ...string[] | string[] |
+| tst.ts:38:36:38:46 | ...string[] | string |
 | tst.ts:38:39:38:44 | string | string |
 | tst.ts:38:39:38:46 | string[] | string[] |
 | tst.ts:39:39:39:68 | [number ... mber[]] | [number, string?, ...number[]] |
 | tst.ts:39:40:39:45 | number | number |
 | tst.ts:39:48:39:53 | string | string |
 | tst.ts:39:48:39:54 | string? | string |
-| tst.ts:39:57:39:67 | ...number[] | number[] |
+| tst.ts:39:57:39:67 | ...number[] | number |
 | tst.ts:39:60:39:65 | number | number |
 | tst.ts:39:60:39:67 | number[] | number[] |
 | tst.ts:40:18:40:24 | unknown | unknown |
 | type_alias.ts:1:6:1:6 | B | boolean |
 | type_alias.ts:1:10:1:16 | boolean | boolean |
 | type_alias.ts:3:8:3:8 | B | boolean |
+| type_alias.ts:5:6:5:17 | ValueOrArray | ValueOrArray<T> |
+| type_alias.ts:5:19:5:19 | T | T |
+| type_alias.ts:5:24:5:24 | T | T |
+| type_alias.ts:5:24:5:49 | T \| Arr ... ray<T>> | ValueOrArray<T> |
+| type_alias.ts:5:28:5:32 | Array | T[] |
+| type_alias.ts:5:28:5:49 | Array<V ... ray<T>> | ValueOrArray<T>[] |
+| type_alias.ts:5:34:5:45 | ValueOrArray | ValueOrArray<T> |
+| type_alias.ts:5:34:5:48 | ValueOrArray<T> | ValueOrArray<T> |
+| type_alias.ts:5:47:5:47 | T | T |
+| type_alias.ts:7:8:7:19 | ValueOrArray | ValueOrArray<T> |
+| type_alias.ts:7:8:7:27 | ValueOrArray<number> | ValueOrArray<number> |
+| type_alias.ts:7:21:7:26 | number | number |
+| type_alias.ts:9:6:9:9 | Json | Json |
+| type_alias.ts:10:5:15:12 | \| strin ...  Json[] | Json |
+| type_alias.ts:10:7:10:12 | string | string |
+| type_alias.ts:11:7:11:12 | number | number |
+| type_alias.ts:12:7:12:13 | boolean | boolean |
+| type_alias.ts:13:7:13:10 | null | null |
+| type_alias.ts:14:7:14:34 | { [prop ...  Json } | { [property: string]: Json; } |
+| type_alias.ts:14:20:14:25 | string | string |
+| type_alias.ts:14:29:14:32 | Json | Json |
+| type_alias.ts:15:7:15:10 | Json | Json |
+| type_alias.ts:15:7:15:12 | Json[] | Json[] |
+| type_alias.ts:17:11:17:14 | Json | Json |
+| type_alias.ts:19:6:19:16 | VirtualNode | VirtualNode |
+| type_alias.ts:20:5:21:56 | \| strin ... Node[]] | VirtualNode |
+| type_alias.ts:20:7:20:12 | string | string |
+| type_alias.ts:21:7:21:56 | [string ... Node[]] | [string, { [key: string]: any; }, ...VirtualNod... |
+| type_alias.ts:21:8:21:13 | string | string |
+| type_alias.ts:21:16:21:37 | { [key: ... : any } | { [key: string]: any; } |
+| type_alias.ts:21:24:21:29 | string | string |
+| type_alias.ts:21:33:21:35 | any | any |
+| type_alias.ts:21:40:21:55 | ...VirtualNode[] | VirtualNode |
+| type_alias.ts:21:43:21:53 | VirtualNode | VirtualNode |
+| type_alias.ts:21:43:21:55 | VirtualNode[] | VirtualNode[] |
+| type_alias.ts:23:15:23:25 | VirtualNode | VirtualNode |
 | type_definitions.ts:3:11:3:11 | I | I<S> |
 | type_definitions.ts:3:13:3:13 | S | S |
 | type_definitions.ts:4:6:4:6 | S | S |
@@ -84,10 +120,10 @@
 | type_definitions.ts:11:10:11:15 | number | number |
 | type_definitions.ts:16:12:16:16 | Color | Color |
 | type_definitions.ts:19:8:19:24 | EnumWithOneMember | EnumWithOneMember |
-| type_definitions.ts:21:6:21:10 | Alias | T[] |
+| type_definitions.ts:21:6:21:10 | Alias | Alias<T> |
 | type_definitions.ts:21:12:21:12 | T | T |
 | type_definitions.ts:21:17:21:17 | T | T |
-| type_definitions.ts:21:17:21:19 | T[] | T[] |
-| type_definitions.ts:22:26:22:30 | Alias | T[] |
-| type_definitions.ts:22:26:22:38 | Alias<number> | number[] |
+| type_definitions.ts:21:17:21:19 | T[] | Alias<T> |
+| type_definitions.ts:22:26:22:30 | Alias | Alias<T> |
+| type_definitions.ts:22:26:22:38 | Alias<number> | Alias<number> |
 | type_definitions.ts:22:32:22:37 | number | number |

javascript/ql/test/library-tests/TypeScript/Types/ReferenceDefinition.expected

@@ -1,3 +1,5 @@
+| Alias<T> | type_definitions.ts:21:1:21:20 | type Alias<T> = T[]; |
+| Alias<number> | type_definitions.ts:21:1:21:20 | type Alias<T> = T[]; |
 | C | type_definition_objects.ts:3:8:3:17 | class C {} |
 | C<T> | type_definitions.ts:8:1:10:1 | class C ...  x: T\\n} |
 | C<number> | type_definitions.ts:8:1:10:1 | class C ...  x: T\\n} |
@@ -9,3 +11,7 @@
 | EnumWithOneMember | type_definitions.ts:18:26:18:31 | member |
 | I<S> | type_definitions.ts:3:1:5:1 | interfa ... x: S;\\n} |
 | I<number> | type_definitions.ts:3:1:5:1 | interfa ... x: S;\\n} |
+| Json | type_alias.ts:9:1:15:13 | type Js ... Json[]; |
+| ValueOrArray<T> | type_alias.ts:5:1:5:50 | type Va ... ay<T>>; |
+| ValueOrArray<number> | type_alias.ts:5:1:5:50 | type Va ... ay<T>>; |
+| VirtualNode | type_alias.ts:19:1:21:57 | type Vi ... ode[]]; |

javascript/ql/test/library-tests/TypeScript/Types/type_alias.ts

@@ -1,3 +1,27 @@
 type B = boolean;
 
 var b: B;
+
+type ValueOrArray<T> = T | Array<ValueOrArray<T>>;
+
+var c: ValueOrArray<number>;
+
+type Json =
+    | string
+    | number
+    | boolean
+    | null
+    | { [property: string]: Json }
+    | Json[];
+
+var json: Json;
+
+type VirtualNode =
+    | string
+    | [string, { [key: string]: any }, ...VirtualNode[]];
+
+const myNode: VirtualNode =
+    ["div", { id: "parent" },
+        ["div", { id: "first-child" }, "I'm the first child"],
+        ["div", { id: "second-child" }, "I'm the second child"]
+    ];

javascript/upgrades/874ebfcd4d2fd346c10ebec145466d9071d78606/upgrade.properties

@@ -0,0 +1,2 @@
+description: add support for TypeScript 3.7 features
+compatibility: backwards