Nullish coalescing

babel.config.js

@@ -78,6 +78,7 @@ module.exports = function(api) {
         { useBuiltIns: true, loose: true },
       ],
       "@babel/plugin-proposal-optional-chaining",
+      "@babel/plugin-proposal-nullish-coalescing-operator",
 
       // Explicitly use the lazy version of CommonJS modules.
       convertESM ? ["@babel/transform-modules-commonjs", { lazy: true }] : null,

package.json

@@ -14,6 +14,7 @@
     "@babel/eslint-plugin-development": "^1.0.1",
     "@babel/plugin-proposal-class-properties": "^7.5.5",
     "@babel/plugin-proposal-export-namespace-from": "^7.5.2",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.4.4",
     "@babel/plugin-proposal-numeric-separator": "^7.2.0",
     "@babel/plugin-proposal-optional-chaining": "^7.6.0",
     "@babel/plugin-transform-modules-commonjs": "^7.6.0",

yarn.lock

@@ -293,6 +293,14 @@
     "@babel/helper-plugin-utils" "^7.0.0"
     "@babel/plugin-syntax-json-strings" "^7.2.0"
 
+"@babel/plugin-proposal-nullish-coalescing-operator@^7.4.4":
+  version "7.4.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-nullish-coalescing-operator/-/plugin-proposal-nullish-coalescing-operator-7.4.4.tgz#41c360d59481d88e0ce3a3f837df10121a769b39"
+  integrity sha512-Amph7Epui1Dh/xxUxS2+K22/MUi6+6JVTvy3P58tja3B6yKTSjwwx0/d83rF7551D6PVSSoplQb8GCwqec7HRw==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    "@babel/plugin-syntax-nullish-coalescing-operator" "^7.2.0"
+
 "@babel/plugin-proposal-numeric-separator@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-numeric-separator/-/plugin-proposal-numeric-separator-7.2.0.tgz#646854daf4cd22fd6733f6076013a936310443ac"
@@ -369,6 +377,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-nullish-coalescing-operator@^7.2.0":
+  version "7.2.0"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-nullish-coalescing-operator/-/plugin-syntax-nullish-coalescing-operator-7.2.0.tgz#f75083dfd5ade73e783db729bbd87e7b9efb7624"
+  integrity sha512-lRCEaKE+LTxDQtgbYajI04ddt6WW0WJq57xqkAZ+s11h4YgfRHhVA/Y2VhfPzzFD4qeLHWg32DMp9HooY4Kqlg==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+
 "@babel/plugin-syntax-numeric-separator@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-numeric-separator/-/plugin-syntax-numeric-separator-7.2.0.tgz#7470fe070c2944469a756752a69a6963135018be"