Fix excessive parenthesization of ternary ?: expressions.

Helps with #366.
benjamn · Sep 10, 2018 · 0475616 · 0475616
1 parent 3d45d4a
commit 0475616
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 2 deletions.
diff --git a/lib/printer.js b/lib/printer.js
@@ -869,9 +869,9 @@ function genericPrintNoParens(path, options, print) {
 
     case "ConditionalExpression":
         return concat([
-            "(", path.call(print, "test"),
+            path.call(print, "test"),
             " ? ", path.call(print, "consequent"),
-            " : ", path.call(print, "alternate"), ")"
+            " : ", path.call(print, "alternate")
         ]);
 
     case "NewExpression":

diff --git a/test/parens.js b/test/parens.js
@@ -328,4 +328,19 @@ describe("parens", function () {
       "(() => {})();"
     );
   });
+
+  it("regression test for issue #366", function () {
+    const code = "typeof a ? b : c";
+    check(code);
+
+    const ast = parse(code);
+    const exprStmt = ast.program.body[0];
+    const callee = exprStmt.expression;
+    exprStmt.expression = b.callExpression(callee, []);
+
+    assert.strictEqual(
+      printer.print(ast).code,
+      "(typeof a ? b : c)()"
+    );
+  });
 });