Merge pull request #704 from asger-semmle/ts-binary-exprs

Approved by esben-semmle

Author: semmle-qlci

change-notes/1.20/extractor-javascript.md

@@ -19,3 +19,4 @@
 ## Changes to code extraction
 
 * The extractor now supports [Nullish Coalescing](https://github.com/tc39/proposal-nullish-coalescing) expressions.
+* The TypeScript extractor now handles the control-flow of logical operators and destructuring assignments more accurately.

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

@@ -41,7 +41,7 @@ public class Main {
 	 * such a way that it may produce different tuples for the same file under the same
 	 * {@link ExtractorConfig}.
 	 */
-	public static final String EXTRACTOR_VERSION = "2018-11-23";
+	public static final String EXTRACTOR_VERSION = "2018-12-19";
 
 	public static final Pattern NEWLINE = Pattern.compile("\n");
 

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

@@ -60,6 +60,7 @@
 import com.semmle.js.ast.InvokeExpression;
 import com.semmle.js.ast.LabeledStatement;
 import com.semmle.js.ast.Literal;
+import com.semmle.js.ast.LogicalExpression;
 import com.semmle.js.ast.MemberDefinition;
 import com.semmle.js.ast.MemberExpression;
 import com.semmle.js.ast.DeclarationFlags;
@@ -825,8 +826,9 @@ private Node convertBinaryExpression(JsonObject node, SourceLocation loc) throws
 		Expression left = convertChild(node, "left");
 		Expression right = convertChild(node, "right");
 		JsonObject operatorToken = node.get("operatorToken").getAsJsonObject();
-		String operatorKind = getKind(operatorToken);
-		if ("CommaToken".equals(operatorKind)) {
+		String operator = getSourceLocation(operatorToken).getSource();
+		switch (operator) {
+		case ",":
 			List<Expression> expressions = new ArrayList<Expression>();
 			if (left instanceof SequenceExpression)
 				expressions.addAll(((SequenceExpression) left).getExpressions());
@@ -837,10 +839,30 @@ private Node convertBinaryExpression(JsonObject node, SourceLocation loc) throws
 			else
 				expressions.add(right);
 			return new SequenceExpression(loc, expressions);
-		} else {
-			String operator = getSourceLocation(operatorToken).getSource();
-			if ("EqualsToken".equals(operatorKind))
-				left = convertLValue(left);
+
+		case "||":
+		case "&&":
+			return new LogicalExpression(loc, operator, left, right);
+
+		case "=":
+			left = convertLValue(left); // For plain assignments, the lhs can be a destructuring pattern.
+			return new AssignmentExpression(loc, operator, left, right);
+
+		case "+=":
+		case "-=":
+		case "*=":
+		case "**=":
+		case "/=":
+		case "%=":
+		case "^=":
+		case "&=":
+		case "|=":
+		case ">>=":
+		case "<<=":
+		case ">>>=":
+			return new AssignmentExpression(loc, operator, convertLValue(left), right);
+
+		default:
 			return new BinaryExpression(loc, operator, left, right);
 		}
 	}

javascript/extractor/tests/ts/input/logicalOr.ts

@@ -0,0 +1,4 @@
+function f(x,y) {
+  if (x || y) {}
+  if (x && y) {}
+}

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

@@ -326,11 +326,11 @@ hasLocation(#20098,#20096)
 exit_cfg_node(#20099,#20004)
 hasLocation(#20099,#20094)
 successor(#20012,#20017)
-successor(#20033,#20037)
-successor(#20043,#20035)
+successor(#20033,#20043)
 successor(#20037,#20039)
-successor(#20041,#20043)
+successor(#20041,#20035)
 successor(#20039,#20041)
+successor(#20043,#20037)
 successor(#20035,#20099)
 successor(#20025,#20027)
 successor(#20027,#20029)