support nullish coalescing operator (#4678)

2021-02-23 21:57:11 +00:00
parent d68d155f93
commit c885660347
16 changed files with 177 additions and 36 deletions
--- a/lib/output.js
+++ b/lib/output.js
@@ -753,7 +753,9 @@ function OutputStream(options) {
        if (p instanceof AST_Binary) {
            var po = p.operator, pp = PRECEDENCE[po];
            var so = this.operator, sp = PRECEDENCE[so];
-            return pp > sp || (pp == sp && this === p[po == "**" ? "left" : "right"]);
+            return pp > sp
+                || po == "??" && (so == "&&" || so == "||")
+                || (pp == sp && this === p[po == "**" ? "left" : "right"]);
        }
        // (foo && bar)()
        if (p instanceof AST_Call) return p.expression === this;