fix corner case in side_effects (#4765)

fixes #4764
This commit is contained in:
Alex Lam S.L 2021-03-12 18:40:28 +00:00 committed by GitHub
parent 24b73a95fa
commit c36c3cb470
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 92 additions and 9 deletions

View File

@ -7266,10 +7266,10 @@ merge(Compressor.prototype, {
}
var drop_body = false;
if (compressor.option("arrows") && is_arrow(exp)) {
if (exp.value) {
exp.value = exp.value.drop_side_effect_free(compressor);
} else {
if (!exp.value) {
drop_body = true;
} else if (!is_async(exp) || is_primitive(compressor, exp.value)) {
exp.value = exp.value.drop_side_effect_free(compressor);
}
} else if (exp instanceof AST_AsyncFunction || exp instanceof AST_Function) {
if (exp.name) {
@ -7280,14 +7280,22 @@ merge(Compressor.prototype, {
}
}
if (drop_body) {
var async = is_async(exp);
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, {
body: value
}) : make_node(AST_EmptyStatement, node);
var value = node.value;
if (value) {
if (async && !is_primitive(compressor, value)) return node;
value = value.drop_side_effect_free(compressor, true);
}
if (!value) return make_node(AST_EmptyStatement, node);
return make_node(AST_SimpleStatement, node, { body: value });
});
scan_local_returns(exp, function(node) {
if (node.value) node.value = node.value.drop_side_effect_free(compressor);
var value = node.value;
if (value) {
if (async && !is_primitive(compressor, value)) return;
node.value = value.drop_side_effect_free(compressor);
}
});
// always shallow clone to ensure stripping of negated IIFEs
self = self.clone();

View File

@ -564,7 +564,7 @@ drop_return: {
input: {
(async function(a) {
while (!console);
return console.log(a);
return !console.log(a);
})(42);
}
expect: {
@ -1408,3 +1408,78 @@ issue_4747: {
expect_stdout: "PASS"
node_version: ">=8"
}
issue_4764_1: {
options = {
side_effects: true,
}
input: {
(async function() {
return {
then() {
console.log("PASS");
},
};
})();
}
expect: {
(async function() {
return {
then() {
console.log("PASS");
},
};
})();
}
expect_stdout: "PASS"
node_version: ">=8"
}
issue_4764_2: {
options = {
arrows: true,
side_effects: true,
}
input: {
(async () => ({
get then() {
console.log("PASS");
},
}))();
}
expect: {
(async () => ({
get then() {
console.log("PASS");
},
}))();
}
expect_stdout: "PASS"
node_version: ">=8"
}
issue_4764_3: {
options = {
side_effects: true,
}
input: {
(async function(o) {
return o;
})({
then() {
console.log("PASS");
},
});
}
expect: {
(async function(o) {
return o;
})({
then() {
console.log("PASS");
},
});
}
expect_stdout: "PASS"
node_version: ">=8"
}