swc/ecmascript/transforms/optimization/tests/simplify.rs
강동윤 21848ce2ea
fix(es/transforms): Fix passes related to optimizations (#1942)
swc_ecma_transofrms_base:
 - `fixer`: Handle `in`.
 - `fixer`: Handle `in` in the head of for statements.
 - `fixer`: Optimize `- (1 / 0)`.
 - `fixer`: Optimize `void 0 === a`.
 - `fixer`: Optimize `a-- && b = c`.
 - `fixer`: Don't de-optimize if statements.
 - `fixer`: Fix handling of if statements.

swc_ecma_transforms_optimization:
 - `dead_branch_remover`: Preserve `var`s in dropped switch cases.
2021-07-20 11:07:36 +00:00

591 lines
14 KiB
Rust

//! Copied from PeepholeIntegrationTest from the google closure compiler.
use std::cell::RefCell;
use std::rc::Rc;
use swc_common::chain;
use swc_common::Mark;
use swc_ecma_parser::EsConfig;
use swc_ecma_parser::{Syntax, TsConfig};
use swc_ecma_transforms_base::helpers::inject_helpers;
use swc_ecma_transforms_base::resolver::resolver;
use swc_ecma_transforms_compat::es2015;
use swc_ecma_transforms_compat::es2016;
use swc_ecma_transforms_compat::es2017;
use swc_ecma_transforms_compat::es2018;
use swc_ecma_transforms_compat::es2020::class_properties;
use swc_ecma_transforms_compat::es3;
use swc_ecma_transforms_module::common_js::common_js;
use swc_ecma_transforms_module::import_analysis::import_analyzer;
use swc_ecma_transforms_module::util::Scope;
use swc_ecma_transforms_optimization::simplify::dce::dce;
use swc_ecma_transforms_optimization::simplify::expr_simplifier;
use swc_ecma_transforms_optimization::simplify::inlining::inlining;
use swc_ecma_transforms_optimization::simplify::simplifier;
use swc_ecma_transforms_proposal::decorators;
use swc_ecma_transforms_testing::test;
use swc_ecma_transforms_testing::test_transform;
use swc_ecma_transforms_typescript::strip;
fn test(src: &str, expected: &str) {
test_transform(
::swc_ecma_parser::Syntax::default(),
|_| chain!(resolver(), simplifier(Default::default())),
src,
expected,
true,
)
}
fn test_same(src: &str) {
test(src, src)
}
macro_rules! to {
($name:ident, $src:expr, $expected:expr) => {
test!(
Default::default(),
|_| chain!(resolver(), simplifier(Default::default())),
$name,
$src,
$expected
);
};
}
macro_rules! optimized_out {
($name:ident, $src:expr) => {
to!($name, $src, "");
};
}
optimized_out!(
single_pass,
"
const a = 1;
if (a) {
const b = 2;
}
"
);
optimized_out!(issue_607, "let a");
to!(
multi_run,
"
let b = 2;
let a = 1;
if (b) { // Removed by first run of remove_dead_branch
a = 2; // It becomes `flat assignment` to a on second run of inlining
}
let c;
if (a) { // Removed by second run of remove_dead_branch
c = 3; // It becomes `flat assignment` to c on third run of inlining.
}
console.log(c); // Prevent optimizing out.
",
"console.log(3)"
);
#[test]
#[ignore] // TODO
fn test_fold_one_child_blocks_integration() {
test(
"function f(){switch(foo()){default:{break}}}",
"function f(){foo()}",
);
test(
"function f(){switch(x){default:{break}}} use(f);",
"function f(){} use(f);",
);
test(
"function f(){switch(x){default:x;case 1:return 2}} use(f);",
"function f(){switch(x){default:case 1:return 2}} use(f);",
);
// ensure that block folding does not break hook ifs
test(
"if(x){if(true){foo();foo()}else{bar();bar()}}",
"if(x){foo();foo()}",
);
test(
"if(x){if(false){foo();foo()}else{bar();bar()}}",
"if(x){bar();bar()}",
);
// Cases where the then clause has no side effects.
test("if(x()){}", "x()");
test("if(x()){} else {x()}", "x()||x()");
test("if(x){}", ""); // Even the condition has no side effect.
test(
"if(a()){A()} else if (b()) {} else {C()}",
"a()?A():b()||C()",
);
test(
"if(a()){} else if (b()) {} else {C()}",
"a() || (b() || C())",
);
test(
"if(a()){A()} else if (b()) {} else if (c()) {} else{D()}",
"a() ? A() : b() || (c() || D())",
);
test(
"if(a()){} else if (b()) {} else if (c()) {} else{D()}",
"a() || (b() || (c() || D()))",
);
test(
"if(a()){A()} else if (b()) {} else if (c()) {} else{}",
"a()?A():b()||c()",
);
// Verify that non-global scope works.
test("function foo(){if(x()){}}", "function foo(){x()}");
}
#[test]
#[ignore] // swc optimizes out everything
fn test_fold_one_child_blocks_string_compare() {
test(
"if (x) {if (y) { var x; } } else{ var z; }",
"if (x) { if (y) var x } else var z",
);
}
#[test]
fn test_necessary_dangling_else() {
test(
"if (x) if (y){ y(); z() } else; else x()",
"if (x) { if(y) { y(); z() } } else x()",
);
}
#[test]
#[ignore] // TODO
fn test_fold_returns_integration() {
// if-then-else duplicate statement removal handles this case:
test("function f(){if(x)return;else return}", "function f(){}");
}
#[test]
fn test_bug1059649() {
// ensure that folding blocks with a single var node doesn't explode
test(
"if(x){var y=3;}var z=5; use(y, z)",
"if(x)var y=3; use(y, 5)",
);
test(
"for(var i=0;i<10;i++){var y=3;}var z=5; use(y, z)",
"for(var i=0;i<10;i++)var y=3; use(y, 5)",
);
test(
"for(var i in x){var y=3;}var z=5; use(y, z)",
"for(var i in x)var y=3; use(y, 5)",
);
test(
"do{var y=3;}while(x);var z=5; use(y, z)",
"do var y=3;while(x); use(y, 5)",
);
}
#[test]
#[ignore] // TODO
fn test_hook_if_integration() {
test(
"if (false){ x = 1; } else if (cond) { x = 2; } else { x = 3; }",
"x=cond?2:3",
);
test("x?void 0:y()", "x||y()");
test("!x?void 0:y()", "x&&y()");
test("x?y():void 0", "x&&y()");
}
#[test]
#[ignore] // normalize
fn test_remove_duplicate_statements_integration() {
test(
concat!(
"function z() {if (a) { return true }",
"else if (b) { return true }",
"else { return true }}",
),
"function z() {return true;}",
);
test(
concat!(
"function z() {if (a()) { return true }",
"else if (b()) { return true }",
"else { return true }}",
),
"function z() {a()||b();return true;}",
);
}
#[test]
#[ignore] // TODO
fn test_fold_logical_op_integration() {
test("if(x && true) z()", "x&&z()");
test("if(x && false) z()", "");
test("if(x || 3) z()", "z()");
test("if(x || false) z()", "x&&z()");
test("if(x==y && false) z()", "");
test("if(y() || x || 3) z()", "y();z()");
}
#[test]
#[ignore] // TODO: This is a bug, but does anyone write code like this?
fn test_fold_bitwise_op_string_compare_integration() {
test("for (;-1 | 0;) {}", "for (;;);");
}
#[test]
fn test_var_lifting_integration() {
test("if(true);else var a;", "");
test("if(false) foo();else var a;", "");
test("if(true)var a;else;", "");
test("if(false)var a;else;", "");
test("if(false)var a,b;", "");
test("if(false){var a;var a;}", "");
test("if(false)var a=function(){var b};", "");
test("if(a)if(false)var a;else var b;", "");
}
#[test]
fn test_bug1438784() {
test_same("for(var i=0;i<10;i++)if(x)x.y;");
}
#[test]
fn test_fold_useless_for_integration() {
test("for(;!true;) { foo() }", "");
test("for(;void 0;) { foo() }", "");
test("for(;undefined;) { foo() }", "");
test("for(;1;) foo()", "for(;;) foo()");
test("for(;!void 0;) foo()", "for(;;) foo()");
// Make sure proper empty nodes are inserted.
// test("if(foo())for(;false;){foo()}else bar()", "foo()||bar()");
test(
"if(foo())for(;false;){foo()}else bar()",
"if (foo()); else bar();",
);
}
#[test]
fn test_fold_useless_do_integration() {
test("do { foo() } while(!true);", "foo()");
test("do { foo() } while(void 0);", "foo()");
test("do { foo() } while(undefined);", "foo()");
test("do { foo() } while(!void 0);", "for(;;)foo();");
// Make sure proper empty nodes are inserted.
// test(
// "if(foo())do {foo()} while(false) else bar()",
// "foo()?foo():bar()",
// );
test(
"if(foo())do {foo()} while(false) else bar()",
"if (foo()) foo(); else bar();",
);
}
#[test]
#[ignore] // TODO
fn test_minimize_expr() {
test("!!true", "");
test("!!x()", "x()");
test("!(!x()&&!y())", "x()||y()");
test("x()||!!y()", "x()||y()");
/* This is similar to the !!true case */
test("!!x()&&y()", "x()&&y()");
}
#[test]
fn test_bug_issue3() {
test_same(concat!(
"function foo() {",
" if(sections.length != 1) children[i] = 0;",
" else var selectedid = children[i]",
"}",
"foo()"
));
}
#[test]
fn test_bug_issue43() {
test_same("function foo() {\n if (a) var b = bar(); else a.b = 1; \n} use(foo);");
}
#[test]
fn test_fold_negative_bug() {
test("for (;-3;){};", "for (;;);");
}
#[test]
#[ignore] // normalize
fn test_no_normalize_labeled_expr() {
test_same("var x; foo:{x = 3;}");
test_same("var x; foo:x = 3;");
}
#[test]
fn test_short_circuit1() {
test("1 && a()", "a()");
}
#[test]
fn test_short_circuit2() {
test("1 && a() && 2", "a()");
}
#[test]
fn test_short_circuit3() {
test("a() && 1 && 2", "a()");
}
#[test]
#[ignore]
fn test_short_circuit4() {
test("a() && (1 && b())", "a() && b()");
test("a() && 1 && b()", "a() && b()");
test("(a() && 1) && b()", "a() && b()");
}
#[test]
#[ignore] // TODO
fn test_minimize_expr_condition() {
test("(x || true) && y()", "y()");
test("(x || false) && y()", "x&&y()");
test("(x && true) && y()", "x && y()");
test("(x && false) && y()", "");
test("a = x || false ? b : c", "a=x?b:c");
test("do {x()} while((x && false) && y())", "x()");
}
// A few miscellaneous cases where one of the peephole passes increases the
// size, but it does it in such a way that a later pass can decrease it.
// Test to make sure the overall change is a decrease, not an increase.
#[test]
#[ignore] // TODO
fn test_misc() {
test("use(x = [foo()] && x)", "use(x = (foo(),x))");
test("x = foo() && false || bar()", "x = (foo(), bar())");
test("if(foo() && false) z()", "foo()");
}
#[test]
#[ignore] // swc strips out whole of this
fn test_comma_spliting_constant_condition() {
test("(b=0,b=1);if(b)x=b;", "b=0;b=1;x=b;");
test("(b=0,b=1);if(b)x=b;", "b=0;b=1;x=b;");
}
#[test]
#[ignore]
fn test_avoid_comma_splitting() {
test("x(),y(),z()", "x();y();z()");
}
#[test]
fn test_object_literal() {
test("({})", "");
test("({a:1})", "");
test("({a:foo()})", "foo()");
test("({'a':foo()})", "foo()");
}
#[test]
fn test_array_literal() {
test("([])", "");
test("([1])", "");
test("([a])", "");
test("([foo()])", "foo()");
}
#[test]
#[ignore] // TODO
fn test_fold_ifs1() {
test(
"function f() {if (x) return 1; else if (y) return 1;}",
"function f() {if (x||y) return 1;}",
);
test(
"function f() {if (x) return 1; else {if (y) return 1; else foo();}}",
"function f() {if (x||y) return 1; foo();}",
);
}
#[test]
#[ignore] // TODO
fn test_fold_ifs2() {
test(
"function f() {if (x) { a(); } else if (y) { a() }}",
"function f() {x?a():y&&a();}",
);
}
#[test]
#[ignore] // TODO
fn test_fold_hook2() {
test(
"function f(a) {if (!a) return a; else return a;}",
"function f(a) {return a}",
);
}
#[test]
#[ignore] // TODO
fn test_template_strings_known_methods() {
test("x = `abcdef`.indexOf('b')", "x = 1");
test("x = [`a`, `b`, `c`].join(``)", "x='abc'");
test("x = `abcdef`.substr(0,2)", "x = 'ab'");
test("x = `abcdef`.substring(0,2)", "x = 'ab'");
test("x = `abcdef`.slice(0,2)", "x = 'ab'");
test("x = `abcdef`.charAt(0)", "x = 'a'");
test("x = `abcdef`.charCodeAt(0)", "x = 97");
test("x = `abc`.toUpperCase()", "x = 'ABC'");
test("x = `ABC`.toLowerCase()", "x = 'abc'");
//test("x = `\t\n\uFEFF\t asd foo bar \r\n`.trim()", "x = 'asd foo bar'");
test("x = parseInt(`123`)", "x = 123");
test("x = parseFloat(`1.23`)", "x = 1.23");
}
test!(
Syntax::Typescript(TsConfig {
decorators: true,
..Default::default()
}),
|_| chain!(
strip(),
resolver(),
dce(Default::default()),
inlining(Default::default())
),
issue_1156_1,
"
interface D {
resolve: any;
reject: any;
}
function d(): D {
let methods;
const promise = new Promise((resolve, reject) => {
methods = { resolve, reject };
});
return Object.assign(promise, methods);
}
class A {
private s: D = d();
a() {
this.s.resolve();
}
b() {
this.s = d();
}
}
new A();
",
"
function d() {
let methods;
const promise = new Promise((resolve, reject)=>{
methods = {
resolve,
reject
};
});
return Object.assign(promise, methods);
}
class A {
a() {
this.s.resolve();
}
b() {
this.s = d();
}
constructor(){
this.s = d();
}
}
new A();
"
);
test!(
Syntax::Es(EsConfig {
dynamic_import: true,
..Default::default()
}),
|t| {
let scope = Rc::new(RefCell::new(Scope::default()));
chain!(
strip(),
decorators(Default::default()),
class_properties(),
simplifier(Default::default()),
es2018(),
es2017(),
es2016(),
es2015(
Mark::fresh(Mark::root()),
Some(t.comments.clone()),
Default::default()
),
es3(true),
import_analyzer(Rc::clone(&scope)),
inject_helpers(),
common_js(Mark::fresh(Mark::root()), Default::default(), Some(scope)),
)
},
issue_389_3,
"
import Foo from 'foo';
Foo.bar = true;
",
"
'use strict';
var _foo = _interopRequireDefault(require('foo'));
function _interopRequireDefault(obj) {
return obj && obj.__esModule ? obj : {
default: obj
};
}
_foo.default.bar = true;
"
);
test!(
Syntax::default(),
|_| expr_simplifier(),
issue_1619_1,
r#"
"use strict";
console.log("\x00" + "\x31");
"#,
r#"
"use strict";
console.log("\x001");
"#,
ok_if_code_eq
);