[CS2] CSX spread attributes: <div {props…} />

src/lexer.coffee

@@ -49,6 +49,7 @@ exports.Lexer = class Lexer
     @importSpecifierList = no    # Used to identify when in an IMPORT {...} FROM? ...
     @exportSpecifierList = no    # Used to identify when in an EXPORT {...} FROM? ...
     @csxDepth = 0                # Used to optimize CSX checks, how deep in CSX we are.
+    @csxSpreadProps = no         # Used to detect if CSX attributes include spreads (<div {props...} />).
 
     @chunkLine =
       opts.line or 0             # The start line for the current @chunk.
@@ -488,6 +489,8 @@ exports.Lexer = class Lexer
   # CSX is like JSX but for CoffeeScript.
   csxToken: ->
     firstChar = @chunk[0]
+    # Check the previous token to detect if attribute is spread.
+    prevChar = if @tokens.length > 0 then @tokens[@tokens.length - 1][0] else ''
     if firstChar is '<'
       match = CSX_IDENTIFIER.exec @chunk[1...]
       return 0 unless match and (
@@ -512,8 +515,13 @@ exports.Lexer = class Lexer
         @csxDepth--
         return 2
       else if firstChar is '{'
-        token = @token '(', '('
-        @ends.push {tag: '}', origin: token}
+        if prevChar == ':'
+          token = @token '(', '('
+          @ends.push {tag: '}', origin: token}
+          @csxSpreadProps = no
+        else
+          @ends.push {tag: '}'}
+          @csxSpreadProps = yes
         return 1
       else if firstChar is '>'
         # Ignore terminators inside a tag.
@@ -540,7 +548,7 @@ exports.Lexer = class Lexer
     else if @atCSXTag 1
       if firstChar is '}'
         @pair firstChar
-        @token ')', ')'
+        @token ')', ')' unless @csxSpreadProps
         @token ',', ','
         return 1
       else

src/nodes.coffee

@@ -1171,7 +1171,7 @@ exports.Obj = class Obj extends Base
         node.error 'cannot have an implicit value in an implicit object'
 
     # Object spread properties. https://github.com/tc39/proposal-object-rest-spread/blob/master/Spread.md
-    return @compileSpread o if @hasSplat()
+    return @compileSpread o if @hasSplat() and not @csx
 
     idt        = o.indent += TAB
     lastNoncom = @lastNonComment @properties
@@ -1195,6 +1195,7 @@ exports.Obj = class Obj extends Base
     answer = []
     answer.push @makeCode if isCompact then '' else '\n'
     for prop, i in props
+      propHasSplat = prop instanceof Splat
       join = if i is props.length - 1
         ''
       else if isCompact and @csx
@@ -1219,12 +1220,22 @@ exports.Obj = class Obj extends Base
         key  = key.properties[0].name
         prop = new Assign key, prop, 'object'
       if key is prop
-        if prop.shouldCache()
-          [key, value] = prop.base.cache o
-          key  = new PropertyName key.value if key instanceof IdentifierLiteral
-          prop = new Assign key, value, 'object'
-        else if not prop.bareLiteral?(IdentifierLiteral)
-          prop = new Assign prop, prop, 'object'
+        unless propHasSplat
+          if prop.shouldCache()
+            [key, value] = prop.base.cache o
+            key  = new PropertyName key.value if key instanceof IdentifierLiteral
+            prop = new Assign key, value, 'object'
+          else unless prop.bareLiteral?(IdentifierLiteral)
+            prop = new Assign prop, prop, 'object'
+        else
+          # Spread in CSX.
+          prop = if @csx then new Literal "{#{prop.compile(o)}}" else prop
+      # Check if CSX attribute is valid.
+      if @csx and prop instanceof Assign
+        prop.variable.error "Unexpected token" unless prop.variable.unwrap() instanceof PropertyName
+        propVal = prop.value.unwrap()
+        unless ((propVal instanceof Parens or propVal instanceof StringWithInterpolations) and propVal.body instanceof Block) or propVal instanceof StringLiteral or propVal instanceof Obj
+          prop.value.error "expected wrapped or quoted CSX attribute"
       if indent then answer.push @makeCode indent
       prop.csx = yes if @csx
       answer.push @makeCode ' ' if @csx and i is 0