[CS2] Fix #4260 and #1349: Splat error with soak properties or expressions

src/nodes.coffee

@@ -2859,22 +2859,20 @@ exports.Param = class Param extends Base
 # A splat, either as a parameter to a function, an argument to a call,
 # or as part of a destructuring assignment.
 exports.Splat = class Splat extends Base
+  constructor: (name) ->
+    super()
+    @name = if name.compile then name else new Literal name
 
   children: ['name']
 
   isAssignable: ->
     @name.isAssignable() and (not @name.isAtomic or @name.isAtomic())
 
-  constructor: (name) ->
-    super()
-    @name = if name.compile then name else new Literal name
-
   assigns: (name) ->
     @name.assigns name
 
-  compileToFragments: (o) ->
-    [ @makeCode('...')
-      @name.compileToFragments(o)... ]
+  compileNode: (o) ->
+    [@makeCode('...'), @name.compileToFragments(o, LEVEL_OP)...]
 
   unwrap: -> @name
 

test/arrays.coffee

@@ -38,7 +38,6 @@ test "array splat expansions with assignments", ->
 
 
 test "mixed shorthand objects in array lists", ->
-
   arr = [
     a:1
     'b'
@@ -58,7 +57,6 @@ test "mixed shorthand objects in array lists", ->
   eq arr[2].b, 1
   eq arr[3], 'b'
 
-
 test "array splats with nested arrays", ->
   nonce = {}
   a = [nonce]
@@ -70,6 +68,54 @@ test "array splats with nested arrays", ->
   list = [1, 2, a...]
   arrayEq list, [1, 2, [nonce]]
 
+test "#4260: splat after existential operator soak", ->
+  a = {b: [3]}
+  foo = (a) -> [a]
+  arrayEq [a?.b...], [3]
+  arrayEq [c?.b ? []...], []
+  arrayEq [...a?.b], [3]
+  arrayEq [...c?.b ? []], []
+  arrayEq foo(a?.b...), [3]
+  arrayEq foo(...a?.b), [3]
+  arrayEq foo(c?.b ? []...), [undefined]
+  arrayEq foo(...c?.b ? []), [undefined]
+  e = yes
+  f = null
+  arrayEq [(a if e)?.b...], [3]
+  arrayEq [(a if f)?.b ? []...], []
+  arrayEq [...(a if e)?.b], [3]
+  arrayEq [...(a if f)?.b ? []], []
+  arrayEq foo((a if e)?.b...), [3]
+  arrayEq foo(...(a if e)?.b), [3]
+  arrayEq foo((a if f)?.b ? []...), [undefined]
+  arrayEq foo(...(a if f)?.b ? []), [undefined]
+
+  # Should not trigger implicit call, e.g. rest ... => rest(...)
+  arrayEq [... a?.b], [3]
+  arrayEq [... c?.b ? []], []
+  arrayEq [a?.b ...], [3]
+  arrayEq [(a if e)?.b ...], [3]
+  arrayEq foo(a?.b ...), [3]
+  arrayEq foo(... a?.b), [3]
+
+test "#1349: trailing if after splat", ->
+  a = [3]
+  b = yes
+  c = null
+  foo = (a) -> [a]
+  arrayEq [a if b...], [3]
+  arrayEq [(a if c) ? []...], []
+  arrayEq [...a if b], [3]
+  arrayEq [...(a if c) ? []], []
+  arrayEq foo((a if b)...), [3]
+  arrayEq foo(...(a if b)), [3]
+  arrayEq foo((a if c) ? []...), [undefined]
+  arrayEq foo(...(a if c) ? []), [undefined]
+
+  # Should not trigger implicit call, e.g. rest ... => rest(...)
+  arrayEq [... a if b], [3]
+  arrayEq [a if b ...], [3]
+
 test "#1274: `[] = a()` compiles to `false` instead of `a()`", ->
   a = false
   fn = -> a = true