feat(javascript): enable logical assignment (#5489)

src/language-js/parser-babylon.js

@@ -33,7 +33,8 @@ function babylonOptions(extraOptions, extraPlugins) {
         ["pipelineOperator", { proposal: "minimal" }],
         "nullishCoalescingOperator",
         "bigInt",
-        "throwExpressions"
+        "throwExpressions",
+        "logicalAssignment"
       ].concat(extraPlugins)
     },
     extraOptions

tests/assignment_expression/babylon/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,8 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`logical-assignment.js - babylon-verify 1`] = `
+a ||= b;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+a ||= b;
+
+`;

tests/assignment_expression/babylon/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, ["babylon"]);

tests/assignment_expression/babylon/logical-assignment.js

@@ -0,0 +1 @@
+a ||= b;