diff options
Diffstat (limited to 'src/js_parser.zig')
| -rw-r--r-- | src/js_parser.zig | 69 |
1 files changed, 39 insertions, 30 deletions
diff --git a/src/js_parser.zig b/src/js_parser.zig index 4ef43865e..894775877 100644 --- a/src/js_parser.zig +++ b/src/js_parser.zig @@ -1028,6 +1028,8 @@ const StaticSymbolName = struct { pub const effect = NewStaticSymbol("effect"); pub const delegateEvents = NewStaticSymbol("delegateEvents"); pub const Solid = NewStaticSymbol("Solid"); + + pub const __merge = NewStaticSymbol("__merge"); }; }; @@ -5102,6 +5104,9 @@ fn NewParser_( if (p.options.features.jsx_optimization_inline) { p.resolveGeneratedSymbol(&p.react_element_type); p.resolveGeneratedSymbol(&p.es6_symbol_global); + if (p.runtime_imports.__merge) |*merge| { + p.resolveGeneratedSymbol(merge); + } } p.resolveGeneratedSymbol(&p.jsx_runtime); p.resolveGeneratedSymbol(&p.jsxs_runtime); @@ -13709,32 +13714,20 @@ fn NewParser_( if (props.items.len == 0) { props_expression = p.e(E.Binary{ .op = Op.Code.bin_logical_or, .left = defaultProps, .right = props_object }, defaultProps.loc); } else { - // we assume that most components don't use defaultProps - // props: !MyComponent.defaultProps ? {myProp: 123} : { ...MyComponent.defaultProps, myProp: 123} - var with_default_props = p.allocator.alloc(G.Property, props_object.data.e_object.properties.len + 1) catch unreachable; - with_default_props[0] = G.Property{ - .key = null, - .value = defaultProps, - .kind = Property.Kind.spread, - .flags = Flags.Property.init( - .{ - .is_spread = true, - }, - ), + var call_args = p.allocator.alloc(Expr, 2) catch unreachable; + call_args[0..2].* = .{ + props_object, + defaultProps, }; - - std.mem.copy(G.Property, with_default_props[1..], props_object.data.e_object.properties.slice()); - props_expression = p.e( - E.If{ - .test_ = p.e(E.Unary{ .op = .un_not, .value = defaultProps }, defaultProps.loc), - .no = p.e( - E.Object{ .properties = G.Property.List.init(with_default_props), .close_brace_loc = e_.close_tag_loc }, - tag.loc, - ), - .yes = props_object, - }, - props_object.loc, - ); + // __merge(props, MyComponent.defaultProps) + // originally, we always inlined here + // see https://twitter.com/jarredsumner/status/1534084541236686848 + // but, that breaks for defaultProps + // we assume that most components do not have defaultProps + // so __merge quickly checks if it needs to merge any props + // and if not, it passes along the props object + // this skips an extra allocation + props_expression = p.callRuntime(tag.loc, "__merge", call_args); } } @@ -13785,11 +13778,6 @@ fn NewParser_( expr.loc, ); - if (p.options.features.jsx_optimization_hoist) { - // if the expression is free of side effects - if (p.exprCanBeRemovedIfUnused(&props_object)) {} - } - return output; } else { // -- The typical jsx automatic transform happens here -- @@ -15418,6 +15406,27 @@ fn NewParser_( return false; } + /// This is based on exprCanBeRemovedIfUnused. + /// The main difference: identifiers, functions, arrow functions cause it to return false + // + // They could technically have side effects if the imported module is a + // CommonJS module and the import item was translated to a property access + // (which esbuild's bundler does) and the property has a getter with side + // effects. + // + // But this is very unlikely and respecting this edge case would mean + // disabling tree shaking of all code that references an export from a + // CommonJS module. It would also likely violate the expectations of some + // developers because the code *looks* like it should be able to be tree + // shaken. + // + // So we deliberately ignore this edge case and always treat import item + // references as being side-effect free. + return true; + }, + .e_if => |ex| { + return p.exprCanBeHoistedForJSX(&ex.test_) and + (p.isSideEffectFreeUnboundIdentifierRef( fn isSideEffectFreeUnboundIdentifierRef(p: *P, value: Expr, guard_condition: Expr, is_yes_branch: bool) bool { if (value.data != .e_identifier or p.symbols.items[value.data.e_identifier.ref.innerIndex()].kind != .unbound or |