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

Fix compression with unused containing destructuring

Browse Source
This commit is contained in:
Anthony Van de Gejuchte
2016-10-31 00:10:52 +01:00
committed by Richard van Velzen
parent abbeb266b5
commit 52ce9a333c
2 changed files with 141 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
lib/compress.js
View File

@@ -1384,6 +1384,8 @@ merge(Compressor.prototype, {
var in_use = [];
var in_use_ids = {}; // avoid expensive linear scans of in_use
var initializations = new Dictionary();
var destructuring_value = null;
var in_definition = false;
// pass 1: find out which symbols are directly used in
// this scope (not in nested scopes).
var scope = this;
@@ -1395,9 +1397,17 @@ merge(Compressor.prototype, {
}
if (node instanceof AST_Definitions && scope === self) {
node.definitions.forEach(function(def){
if (def.is_destructuring()) return; /* Destructurings are type assertions! */
if (def.value) {
initializations.add(def.name.name, def.value);
if (def.is_destructuring()) {
var destructuring_cache = destructuring_value;
destructuring_value = def.value;
in_definition = true;
def.walk(tw);
in_definition = false;
destructuring_value = destructuring_cache;
} else {
initializations.add(def.name.name, def.value);
}
if (def.value.has_side_effects(compressor)) {
def.value.walk(tw);
}
@@ -1420,6 +1430,39 @@ merge(Compressor.prototype, {
scope = save_scope;
return true;
}
if (node instanceof AST_Destructuring) {
if (!in_definition) {
return true;
}
for (var i = 0; i < node.names.length; i++) {
if (node.names[i] instanceof AST_Destructuring) {
node.names[i].walk(tw);
}
else if (node.names[i] instanceof AST_Expansion) {
if (node.names[i].expression instanceof AST_Symbol) {
initializations.add(node.names[i].expression.name, destructuring_value);
} else {
throw new Error(string_template("Can't handle expansion of type: {type}", {
type: Object.getPrototypeOf(node.names[i].expression).TYPE
}));
}
}
else if (node.names[i] instanceof AST_Hole) {
continue;
}
else if (node.names[i] instanceof AST_ObjectKeyVal && typeof node.names[i].key === "string") {
initializations.add(node.names[i].key, destructuring_value);
}
else if (node.names[i] instanceof AST_Symbol) {
initializations.add(node.names[i].name, destructuring_value);
} else {
throw new Error(string_template("Unknown destructuring element of type: {type}", {
type: Object.getPrototypeOf(node.names[i]).TYPE
}));
}
}
return true;
}
}
});
self.walk(tw);

96
test/compress/destructuring.js
View File

@@ -104,3 +104,99 @@ destructuring_expressions: {
expect_exact: "({a,b});[{a}];f({x});"
}
destructuring_remove_unused_1: {
options = {
unused: true
}
input: {
function a() {
var unused = "foo";
var a = [1];
var [b] = a;
f(b);
}
function b() {
var unused = "foo";
var a = {b: 1};
var {b} = a;
f(b);
}
function c() {
var unused = "foo";
var a = [[1]];
var [[b]] = a;
f(b);
}
function d() {
var unused = "foo";
var a = {b: {b:1}};
var {b:{b}} = a;
f(b);
}
function e() {
var unused = "foo";
var a = [1, 2, 3, 4, 5];
var [b, ...c] = a;
f(b, c);
}
}
expect: {
function a() {
var a = [1];
var [b] = a;
f(b);
}
function b() {
var a = {b: 1};
var {b} = a;
f(b);
}
function c() {
var a = [[1]];
var [[b]] = a;
f(b);
}
function d() {
var a = {b: {b:1}};
var {b:{b}} = a;
f(b);
}
function e() {
var a = [1, 2, 3, 4, 5];
var [b, ...c] = a;
f(b, c);
}
}
}
destructuring_remove_unused_2: {
options = {
unused: true
}
input: {
function a() {
var unused = "foo";
var a = [,,1];
var [b] = a;
f(b);
}
function b() {
var unused = "foo";
var a = [{a: [1]}];
var [{b: a}] = a;
f(b);
}
}
expect: {
function a() {
var a = [,,1];
var [b] = a;
f(b);
}
function b() {
var a = [{a: [1]}];
var [{b: a}] = a;
f(b);
}
}
}