fix(es/transforms/optimization): Preserve missing object members (#1567)

swc_ecma_transforms_optimization: - Don't replace missing object members with undefined
swc-project · Apr 12, 2021 · e43de77 · e43de77
1 parent 14edb69
commit e43de77
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Showing 3 changed files with 9 additions and 6 deletions.
diff --git a/ecmascript/transforms/optimization/Cargo.toml b/ecmascript/transforms/optimization/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc_ecma_transforms_optimization"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.15.2"
+version = "0.15.3"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

diff --git a/ecmascript/transforms/optimization/src/simplify/branch/tests.rs b/ecmascript/transforms/optimization/src/simplify/branch/tests.rs
@@ -1340,6 +1340,7 @@ fn test_object_literal() {
     test("({a:1})", "");
     test("({a:foo()})", "foo()");
     test("({'a':foo()})", "foo()");
+    test("({}).foo", "({}).foo");
     // Object-spread may trigger getters.
     test_same("({...a})");
     test_same("({...foo()})");

diff --git a/ecmascript/transforms/optimization/src/simplify/expr/mod.rs b/ecmascript/transforms/optimization/src/simplify/expr/mod.rs
@@ -249,11 +249,13 @@ impl SimplifyExpr {
                                 once(Box::new(Expr::Object(ObjectLit { props, span }))),
                             )
                         }
-                        None => preserve_effects(
-                            span,
-                            *undefined(span),
-                            once(Box::new(Expr::Object(ObjectLit { props, span }))),
-                        ),
+                        None => Expr::Member(MemberExpr {
+                            obj: ExprOrSuper::Expr(Box::new(Expr::Object(ObjectLit {
+                                props,
+                                span,
+                            }))),
+                            ..e
+                        }),
                     }
                 }
                 _ => Expr::Member(MemberExpr {