commit c7524cc29613caa00326c5cb7c5d78a4ecec9618
author Stephen Adams <sra@google.com> Mon Jun 24 19:35:07 2019 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Mon Jun 24 19:35:07 2019 +0000
tree 014c68de6a4911139ec802c7f0a7f66589f81835
parent bc8b6fb94de1796bdcb7b02f0c5ce14ba369400a

[js_ast] Don't rewrite compound assignments

Bug: 37337
Change-Id: Ibda0d9233d480cc64732e9e17182b55cde77baf2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107181
Reviewed-by: Mayank Patke <fishythefish@google.com>
Commit-Queue: Stephen Adams <sra@google.com>

pkg/js_ast/lib/src/printer.dart

diff --git a/pkg/js_ast/lib/src/printer.dart b/pkg/js_ast/lib/src/printer.dart
index 399ab56..400dc42 100644
--- a/pkg/js_ast/lib/src/printer.dart
+++ b/pkg/js_ast/lib/src/printer.dart
@@ -763,7 +763,10 @@
       // Output 'a += 1' as '++a' and 'a -= 1' as '--a'.
       _outputIncDec(op, assignment.leftHandSide);
       return;
-    } else if (leftHandSide is VariableUse && rightHandSide is Binary) {
+    }
+    if (!assignment.isCompound &&
+        leftHandSide is VariableUse &&
+        rightHandSide is Binary) {
       Node rLeft = undefer(rightHandSide.left);
       Node rRight = undefer(rightHandSide.right);
       String op = rightHandSide.op;

pkg/js_ast/test/deferred_expression_test.dart

diff --git a/pkg/js_ast/test/deferred_expression_test.dart b/pkg/js_ast/test/deferred_expression_test.dart
index 397aaaa..c91a151 100644
--- a/pkg/js_ast/test/deferred_expression_test.dart
+++ b/pkg/js_ast/test/deferred_expression_test.dart
@@ -29,6 +29,25 @@
   test(map, '# = # - 1', [deferred, variableUseAlias], '--variable');
   test(map, '# = # + 2', [variableUse, variableUseAlias], 'variable += 2');
   test(map, '# = # + 2', [deferred, variableUseAlias], 'variable += 2');
+  test(map, '# = # * 2', [variableUse, variableUseAlias], 'variable *= 2');
+  test(map, '# = # * 2', [deferred, variableUseAlias], 'variable *= 2');
+
+  test(map, '# += # + 1', [variableUse, variableUseAlias],
+      'variable += variable + 1');
+  test(map, '# += # + 1', [deferred, variableUseAlias],
+      'variable += variable + 1');
+  test(map, '# += # - 1', [variableUse, variableUseAlias],
+      'variable += variable - 1');
+  test(map, '# += # - 1', [deferred, variableUseAlias],
+      'variable += variable - 1');
+  test(map, '# += # + 2', [variableUse, variableUseAlias],
+      'variable += variable + 2');
+  test(map, '# += # + 2', [deferred, variableUseAlias],
+      'variable += variable + 2');
+  test(map, '# += # * 2', [variableUse, variableUseAlias],
+      'variable += variable * 2');
+  test(map, '# += # * 2', [deferred, variableUseAlias],
+      'variable += variable * 2');
 }
 
 void test(Map<Expression, DeferredExpression> map, String template,