JoBoEVD/UglifyJS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

enhance side_effects (#4638)

Browse Source
This commit is contained in:
Alex Lam S.L
2021-02-10 10:09:54 +00:00
committed by GitHub
parent 5ec82e5801
commit a98ec7e4df
3 changed files with 77 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
lib/compress.js
View File

@@ -6922,9 +6922,29 @@ merge(Compressor.prototype, {
exprs = trim(exprs, compressor, first_in_statement, array_spread);
return exprs && make_sequence(self, exprs.map(convert_spread));
}
var def;
if ((is_arrow(exp) && !exp.value || exp instanceof AST_AsyncFunction || exp instanceof AST_Function)
&& !(exp.name && (def = exp.name.definition()).references.length > def.replaced)) {
if (compressor.option("yields") && is_generator(exp)) {
var call = self.clone();
call.expression = make_node(AST_Function, exp, exp);
call.expression.body = [];
var opt = call.transform(compressor);
if (opt !== call) return opt.drop_side_effect_free(compressor, first_in_statement);
}
var drop_body = false;
if (compressor.option("arrows") && is_arrow(exp)) {
if (exp.value) {
exp.value = exp.value.drop_side_effect_free(compressor);
} else {
drop_body = true;
}
} else if (exp instanceof AST_AsyncFunction || exp instanceof AST_Function) {
if (exp.name) {
var def = exp.name.definition();
drop_body = def.references.length == def.replaced;
} else {
drop_body = true;
}
}
if (drop_body) {
exp.process_expression(false, function(node) {
var value = node.value && node.value.drop_side_effect_free(compressor, true);
return value ? make_node(AST_SimpleStatement, node, {