JS: Preserve information about 'defer' keyword

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

@@ -26,11 +26,11 @@ public class ImportDeclaration extends Statement implements INodeWithSymbol {
 
   private int symbol = -1;
 
-  private boolean hasTypeKeyword;
+  private ImportPhaseModifier phaseModifier;
 
   public ImportDeclaration(
       SourceLocation loc, List<ImportSpecifier> specifiers, Literal source, Expression attributes) {
-    this(loc, specifiers, source, attributes, false);
+    this(loc, specifiers, source, attributes, ImportPhaseModifier.NONE);
   }
 
   public ImportDeclaration(
@@ -38,12 +38,12 @@ public class ImportDeclaration extends Statement implements INodeWithSymbol {
       List<ImportSpecifier> specifiers,
       Literal source,
       Expression attributes,
-      boolean hasTypeKeyword) {
+      ImportPhaseModifier phaseModifier) {
     super("ImportDeclaration", loc);
     this.specifiers = specifiers;
     this.source = source;
     this.attributes = attributes;
-    this.hasTypeKeyword = hasTypeKeyword;
+    this.phaseModifier = phaseModifier;
   }
 
   public Literal getSource() {
@@ -79,6 +79,15 @@ public class ImportDeclaration extends Statement implements INodeWithSymbol {
 
   /** Returns true if this is an <code>import type</code> declaration. */
   public boolean hasTypeKeyword() {
-    return hasTypeKeyword;
+    return phaseModifier == ImportPhaseModifier.TYPE;
+  }
+
+  /** Returns true if this is an <code>import defer</code> declaration. */
+  public boolean hasDeferKeyword() {
+    return phaseModifier == ImportPhaseModifier.DEFER;
+  }
+
+  public ImportPhaseModifier getPhaseModifier() {
+    return phaseModifier;
   }
 }

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

@@ -0,0 +1,10 @@
+package com.semmle.js.ast;
+
+/**
+ * A keyword that may appear on import declarations.
+ */
+public enum ImportPhaseModifier {
+    NONE,
+    DEFER,
+    TYPE,
+}

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

@@ -564,7 +564,7 @@ public class NodeCopier implements Visitor<Void, INode> {
         copy(nd.getSpecifiers()),
         copy(nd.getSource()),
         copy(nd.getAttributes()),
-        nd.hasTypeKeyword());
+        nd.getPhaseModifier());
   }
 
   @Override

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

@@ -1833,6 +1833,9 @@ public class ASTExtractor {
       if (nd.hasTypeKeyword()) {
         trapwriter.addTuple("has_type_keyword", lbl);
       }
+      if (nd.hasDeferKeyword()) {
+        trapwriter.addTuple("has_defer_keyword", lbl);
+      }
       return lbl;
     }
 

javascript/extractor/src/com/semmle/ts/extractor/TypeScriptASTConverter.java

@@ -52,6 +52,7 @@ import com.semmle.js.ast.IfStatement;
 import com.semmle.js.ast.ImportDeclaration;
 import com.semmle.js.ast.ImportDefaultSpecifier;
 import com.semmle.js.ast.ImportNamespaceSpecifier;
+import com.semmle.js.ast.ImportPhaseModifier;
 import com.semmle.js.ast.ImportSpecifier;
 import com.semmle.js.ast.InvokeExpression;
 import com.semmle.js.ast.LabeledStatement;
@@ -1404,7 +1405,7 @@ public class TypeScriptASTConverter {
     Literal src = tryConvertChild(node, "moduleSpecifier", Literal.class);
     Expression attributes = convertChild(node, "attributes");
     List<ImportSpecifier> specifiers = new ArrayList<>();
-    boolean hasTypeKeyword = false;
+    ImportPhaseModifier phaseModifier = ImportPhaseModifier.NONE;
     if (hasChild(node, "importClause")) {
       JsonObject importClause = node.get("importClause").getAsJsonObject();
       if (hasChild(importClause, "name")) {
@@ -1418,10 +1419,22 @@ public class TypeScriptASTConverter {
           specifiers.addAll(convertChildren(namedBindings, "elements"));
         }
       }
-      hasTypeKeyword = importClause.get("isTypeOnly").getAsBoolean();
+      if (hasChild(importClause, "phaseModifier")) {
+        String name = metadata.getSyntaxKindName(importClause.get("phaseModifier").getAsInt());
+        switch (name) {
+          case "DeferKeyword": {
+            phaseModifier = ImportPhaseModifier.DEFER;
+            break;
+          }
+          case "TypeKeyword": {
+            phaseModifier = ImportPhaseModifier.TYPE;
+            break;
+          }
+        }
+      }
     }
     ImportDeclaration importDecl =
-        new ImportDeclaration(loc, specifiers, src, attributes, hasTypeKeyword);
+        new ImportDeclaration(loc, specifiers, src, attributes, phaseModifier);
     attachSymbolInformation(importDecl, node);
     return importDecl;
   }