//! Copied from PeepholeIntegrationTest from the google closure compiler. #![deny(warnings)] use swc_common::{chain, pass::Repeat, Mark}; use swc_ecma_parser::{Syntax, TsConfig}; use swc_ecma_transforms_base::{helpers::inject_helpers, resolver}; use swc_ecma_transforms_compat::{es2015, es2016, es2017, es2018, es2022::class_properties, es3}; use swc_ecma_transforms_module::{common_js::common_js, import_analysis::import_analyzer}; use swc_ecma_transforms_optimization::simplify::{ dce::{self, dce}, dead_branch_remover, expr_simplifier, inlining::{self, inlining}, }; use swc_ecma_transforms_proposal::decorators; use swc_ecma_transforms_testing::{test, test_transform}; use swc_ecma_transforms_typescript::strip; fn test(src: &str, expected: &str) { test_transform( ::swc_ecma_parser::Syntax::default(), |_| { let unresolved_mark = Mark::new(); let top_level_mark = Mark::new(); chain!( resolver(unresolved_mark, top_level_mark, false), Repeat::new(chain!( expr_simplifier(unresolved_mark, Default::default()), inlining::inlining(Default::default()), dead_branch_remover(unresolved_mark), dce::dce(Default::default(), unresolved_mark) )), ) }, src, expected, true, ) } fn test_same(src: &str) { test(src, src) } macro_rules! to { ($name:ident, $src:expr, $expected:expr) => { test!( Default::default(), |_| { let unresolved_mark = Mark::new(); let top_level_mark = Mark::new(); chain!( resolver(unresolved_mark, top_level_mark, false), Repeat::new(chain!( expr_simplifier(unresolved_mark, Default::default()), inlining::inlining(Default::default()), dead_branch_remover(unresolved_mark), dce::dce(Default::default(), unresolved_mark) )), ) }, $name, $src, $expected ); }; } macro_rules! optimized_out { ($name:ident, $src:expr) => { to!($name, $src, ""); }; } to!( single_pass, " const a = 1; if (a) { const b = 2; } ", " const a = 1; a " ); 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};", ""); // TODO(kdy1): We can optimize this. // test("if(a)if(false)var a;else var b;", ""); test("if(a)if(false)var a;else var b;", "if(a) var a;"); } #[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( concat!( "function foo() {", " if(sections.length != 1) children[i] = 0;", " else var selectedid = children[i]", "}", "foo()" ), concat!( "function foo() {", " if(sections.length != 1) children[i] = 0;", " else children[i]", "}", "foo()" ), ); } #[test] fn test_bug_issue43() { test_same("function foo() {\n if (a) 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])", "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() }), |t| { let unresolved_mark = Mark::new(); let top_level_mark = Mark::new(); chain!( resolver(unresolved_mark, top_level_mark, false), strip(top_level_mark), class_properties( Some(t.comments.clone()), class_properties::Config { set_public_fields: true, ..Default::default() } ), dce(Default::default(), unresolved_mark), 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(Default::default()), |t| { let unresolved_mark = Mark::new(); let top_level_mark = Mark::new(); chain!( decorators(Default::default()), resolver(unresolved_mark, top_level_mark, false), strip(top_level_mark), class_properties(Some(t.comments.clone()), Default::default()), Repeat::new(chain!( expr_simplifier(unresolved_mark, Default::default()), inlining::inlining(Default::default()), dead_branch_remover(unresolved_mark), dce::dce(Default::default(), unresolved_mark) )), es2018(Default::default()), es2017( Default::default(), Some(t.comments.clone()), unresolved_mark ), es2016(), es2015( unresolved_mark, Some(t.comments.clone()), Default::default() ), es3(true), import_analyzer(false.into(), false), inject_helpers(unresolved_mark), common_js( Mark::fresh(Mark::root()), Default::default(), Default::default(), Some(t.comments.clone()) ), ) }, issue_389_3, " import Foo from 'foo'; Foo.bar = true; ", " \"use strict\"; Object.defineProperty(exports, \"__esModule\", { value: true }); var _foo = _interop_require_default(require(\"foo\")); function _interop_require_default(obj) { return obj && obj.__esModule ? obj : { default: obj }; } _foo.default.bar = true; " ); test!( Syntax::default(), |_| { let top_level_mark = Mark::fresh(Mark::root()); expr_simplifier(top_level_mark, Default::default()) }, issue_1619_1, r#" "use strict"; console.log("\x00" + "\x31"); "#, r#" "use strict"; console.log("\x001"); "#, ok_if_code_eq ); test!( Syntax::default(), |_| { let top_level_mark = Mark::fresh(Mark::root()); dead_branch_remover(top_level_mark) }, issue_2466_1, " const X = { run() { console.log(this === globalThis); }, }; X.run(); (0, X.run)(); ", " const X = { run() { console.log(this === globalThis); }, }; X.run(); (0, X.run)(); " ); test!( Syntax::default(), |_| { let top_level_mark = Mark::fresh(Mark::root()); dead_branch_remover(top_level_mark) }, issue_4272, " function oe() { var e, t; return t !== i && (e, t = t), e = t; } ", " function oe() { var e, t; return t !== i && (e, t), e = t; } " ); test!( Syntax::default(), |_| { let unresolved_mark = Mark::new(); let top_level_mark = Mark::new(); chain!( resolver(unresolved_mark, top_level_mark, false), Repeat::new(chain!( inlining(Default::default()), dead_branch_remover(unresolved_mark) )) ) }, issue_4173, " function emit(type) { const e = events[type]; if (Array.isArray(e)) { for (let i = 0; i < e.length; i += 1) { e[i].apply(this); } } } ", " function emit(type) { const e = events[type]; if (Array.isArray(e)) for(let i = 0; i < e.length; i += 1)e[i].apply(this); } " );