Fix #5128: parens around default param (#5167)

helixbass · GeoffreyBooth · commit ca275c2a1cb1 · 2019-03-14T18:14:35.000-07:00
* compile params at LEVEL_PAREN

* test
diff --git a/lib/coffeescript/nodes.js b/lib/coffeescript/nodes.js
diff --git a/src/nodes.coffee b/src/nodes.coffee
@@ -2744,7 +2744,7 @@ exports.Code = class Code extends Base
       # (e.g. `ref`), shift those into the parent scope since we can’t put a
       # `var` line inside a function parameter list.
       scopeVariablesCount = o.scope.variables.length
-      signature.push param.compileToFragments(o)...
+      signature.push param.compileToFragments(o, LEVEL_PAREN)...
       if scopeVariablesCount isnt o.scope.variables.length
         generatedVariables = o.scope.variables.splice scopeVariablesCount
         o.scope.parent.variables.push generatedVariables...
diff --git a/test/functions.coffee b/test/functions.coffee
@@ -493,3 +493,7 @@ test "#4657: destructured array parameters", ->
   result = f [1, 2, 3, 4]
   arrayEq result.a, [1, 2, 3]
   eq result.b, 4
+
+test "#5128: default parameters of function in binary operation", ->
+  foo = yes or (a, b = {}) -> null
+  eq foo, yes
