feat(literals): add support for default assignment for object destruc…

…turing

src/lang/literals/object.js

@@ -17,21 +17,46 @@ const value_expr = (ctx, key)=> {
 };
 
 
+const default_assignment = (ctx, left)=> {
+  const expr_ctx = advance(ctx);
+
+  const [right, next_ctx] = expression(expr_ctx, 0);
+  const {loc: {end}} = right;
+
+  //TODO: assign and this func should use common code
+  return [
+    {type: 'assign', op: '=', left, right, loc: {...left.loc, end}},
+    next_ctx
+  ];
+};
+
+
 const key_expr = (ctx)=> {
   if (next_is(ctx, '`') || next_is(ctx, '...')) {
     return expression(ctx, 0);
   }
 
   const key_ctx = advance(ctx);
   const loc = curr_loc(key_ctx);
+  const key = {type: other_token, value: curr_value(key_ctx), loc};
+
+  if (next_is(key_ctx, '=')) {
+    return default_assignment(key_ctx, key);
+  }
 
-  return [{type: other_token, value: curr_value(key_ctx), loc}, key_ctx];
+  return [key, key_ctx];
 };
 
 
 const prop_expr = (ctx)=> {
-  const [key, value_ctx] = key_expr(ctx);
-  const [value, next_ctx] = value_expr(value_ctx, key);
+  const [key_or_default, value_ctx] = key_expr(ctx);
+  const [value, next_ctx] = value_expr(value_ctx, key_or_default);
+
+  const key = (
+    key_or_default.type === 'assign'
+      ? key_or_default.left
+      :key_or_default
+  );
 
   const {start} = key.loc;
   const {end} = value.loc;

src/lang/literals/object.test.js

@@ -95,6 +95,7 @@ describe('object {...}', ()=> {
     });
   });
 
+
   it('parses single str prop: {`foo`: spam}', ()=> {
     expect(
       parse_expr('{`foo`: spam}')
@@ -115,6 +116,28 @@ describe('object {...}', ()=> {
       }
     });
   });
+
+
+  it('parses default assignment prop: {foo=123}', ()=> {
+    expect(
+      parse_expr(`{foo=123}`)
+    ).toEqual({
+      type: 'object',
+      props: [{
+        type: 'prop',
+        key: parse_expr(` foo`),
+        value: parse_expr(` foo=123`),
+        loc: {
+          start: {pos: 1, line: 1, column: 1},
+          end: {pos: 8, line: 1, column: 8}
+        }
+      }],
+      loc: {
+        start: {pos: 0, line: 1, column: 0},
+        end: {pos: 9, line: 1, column: 9}
+      }
+    });
+  });
 });