toBlockArrowFunctionExpression now preserves skinny arrows

Addresses wcjohnson/lightscript#29

src/functions.lsc

@@ -72,8 +72,9 @@ export replaceWithArrowFunction(path) ->
   path.replaceWith(toArrowFunction(path.node))
 
 export toBlockArrowFunctionExpression(node) ->
-  let { params, body, async } = node
+  let { params, body, async, skinny } = node
   fn = t.arrowFunctionExpression(params, body~toBlockStatement(), async)~atNode(node)
+  if skinny: fn.skinny = true
   if node.returnType: fn.returnType = node.returnType
   if node.typeParameters: fn.typeParameters = node.typeParameters
 

src/safe.lsc

@@ -3,8 +3,6 @@ import atNode from 'ast-loc-utils/lib/placeAtNode'
 import { hoistRef, isSimple } from './ref'
 import { isa } from './is'
 
-import { getLoc, placeTreeAtLocWhenUnplaced as allAtLoc } from 'ast-loc-utils'
-
 // Optional-replacement algorithm based on babel-plugin-transform-optional-chaining
 // See https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-optional-chaining/src/index.js
 

test/fixtures/safe-member-expression/this/actual.js

@@ -0,0 +1 @@
+-> this?.a

test/fixtures/safe-member-expression/this/expected.js

@@ -0,0 +1,3 @@
+(function () {
+  return this == null ? void 0 : this.a;
+});