Allow expand in array literals

lib/ast.js

@@ -371,15 +371,15 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     }
 }, AST_Scope);
 
-var AST_Expansion = DEFNODE("Expansion", "symbol", {
+var AST_Expansion = DEFNODE("Expansion", "expression", {
     $documentation: "An expandible argument, such as ...rest, a splat, such as [1,2,...all], or an expansion in a variable declaration, such as var [first, ...rest] = list",
     $propdoc: {
-        symbol: "AST_Symbol the thing to be expanded"
+        expression: "AST_Symbol the thing to be expanded"
     },
     _walk: function(visitor) {
         var self = this;
         return visitor._visit(this, function(){
-            self.symbol.walk(visitor);
+            self.expression.walk(visitor);
         });
     }
 });
@@ -516,7 +516,7 @@ var AST_Destructuring = DEFNODE("Destructuring", "names is_array default", {
                 out.push(node);
             }
             if (node instanceof AST_Expansion) {
-                out.push(node.symbol);
+                out.push(node.expression);
             }
         }));
         return out;

lib/output.js

@@ -657,7 +657,7 @@ function OutputStream(options) {
 
     DEFPRINT(AST_Expansion, function (self, output) {
         output.print('...');
-        self.symbol.print(output);
+        self.expression.print(output);
     });
 
     DEFPRINT(AST_Destructuring, function (self, output) {

lib/parse.js

@@ -1166,7 +1166,7 @@ function parse($TEXT, options) {
                 next();
                 a.push(new AST_Expansion({
                     start: prev(),
-                    symbol: as_symbol(AST_SymbolFunarg),
+                    expression: as_symbol(AST_SymbolFunarg),
                     end: S.token,
                 }));
             } else {
@@ -1385,7 +1385,7 @@ function parse($TEXT, options) {
                 var symbol = _make_symbol(sym_type);
                 children.push(new AST_Expansion({
                     start: prev(),
-                    symbol: symbol,
+                    expression: symbol,
                     end: S.token
                 }));
                 next();
@@ -1586,6 +1586,9 @@ function parse($TEXT, options) {
             if (allow_trailing_comma && is("punc", closing)) break;
             if (is("punc", ",") && allow_empty) {
                 a.push(new AST_Hole({ start: S.token, end: S.token }));
+            } else if (is("expand", "...")) {
+                next();
+                a.push(new AST_Expansion({start: S.token, expression: expression(),end: S.token}));
             } else {
                 a.push(expression(false));
             }
@@ -1956,7 +1959,7 @@ function parse($TEXT, options) {
                 next();
                 args.push(new AST_Expansion({
                     start: prev(),
-                    symbol: as_symbol(AST_SymbolFunarg)
+                    expression: as_symbol(AST_SymbolFunarg)
                 }));
             } else {
                 args.push(expression(false));

lib/transform.js

@@ -227,4 +227,8 @@ TreeTransformer.prototype = new TreeWalker;
         self.value = self.value.transform(tw);
     });
 
+    _(AST_Expansion, function(self, tw){
+        self.expression = self.expression.transform(tw);
+    });
+
 })();

test/compress/arrays.js

@@ -72,3 +72,76 @@ constant_join_2: {
         var f = "strstr" + variable + "foobarmoo" + foo;
     }
 }
+
+spread_with_variable_as_last_element: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+}
+
+spread_with_variable_in_middle: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+}
+
+spread_with_variable_at_front: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+}
+
+spread_with_variable_at_front_after_elisions: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+}
+
+spread_with_array_at_end: {
+    input: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+    expect: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+}
+
+spread_with_logical_expression_at_end: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 2, 3, ...[2+2]]
+    }
+    expect: {
+        var a = [1, 2, 3, ...[4]]
+    }
+}
+
+spread_with_logical_expression_at_middle: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 1, ...[1+1, 1+2, 2+3], 8]
+    }
+    expect: {
+        var a = [1, 1, ...[2, 3, 5], 8]
+    }
+}

test/parser.js

@@ -117,7 +117,7 @@ module.exports = function () {
 
     ok.equal(expanding_def.name.names[0].TYPE, 'SymbolVar');
     ok.equal(expanding_def.name.names[1].TYPE, 'Expansion');
-    ok.equal(expanding_def.name.names[1].symbol.TYPE, 'SymbolVar');
+    ok.equal(expanding_def.name.names[1].expression.TYPE, 'SymbolVar');
 
     // generators
     var generators_def = UglifyJS.parse('function* fn() {}').body[0];