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Diffstat (limited to 'test/bun.js/transpiler.test.js')
| -rw-r--r-- | test/bun.js/transpiler.test.js | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/test/bun.js/transpiler.test.js b/test/bun.js/transpiler.test.js index 76356d90f..2be937d78 100644 --- a/test/bun.js/transpiler.test.js +++ b/test/bun.js/transpiler.test.js @@ -1680,6 +1680,435 @@ class Foo { expectPrinted("a = !(b, c)", "a = (b , !c)"); }); + it("substitution", () => { + var transpiler = new Bun.Transpiler({ + inline: true, + platform: "bun", + allowBunRuntime: false, + }); + function check(input, output) { + expect( + transpiler + .transformSync("export function hello() {\n" + input + "\n}") + .trim() + .replaceAll(/^ /gm, ""), + ).toBe( + "export function hello() {\n" + + output + + "\n}".replaceAll(/^ /gm, ""), + ); + } + check("var x = 1; return x", "var x = 1;\nreturn x;"); + check("let x = 1; return x", "return 1;"); + check("const x = 1; return x", "return 1;"); + + check("let x = 1; if (false) x++; return x", "return 1;"); + // TODO: comma operator + // check("let x = 1; if (true) x++; return x", "let x = 1;\nreturn x++, x;"); + check("let x = 1; return x + x", "let x = 1;\nreturn x + x;"); + + // Can substitute into normal unary operators + check("let x = 1; return +x", "return 1;"); + check("let x = 1; return -x", "return -1;"); + check("let x = 1; return !x", "return false;"); + check("let x = 1; return ~x", "return ~1;"); + // TODO: remove needless return undefined; + // check("let x = 1; return void x", "let x = 1;"); + + // esbuild does this: + // check("let x = 1; return typeof x", "return typeof 1;"); + // we do: + check("let x = 1; return typeof x", 'return "number";'); + + // Check substituting a side-effect free value into normal binary operators + // esbuild does this: + // check("let x = 1; return x + 2", "return 1 + 2;"); + // we do: + check("let x = 1; return x + 2", "return 3;"); + check("let x = 1; return 2 + x", "return 3;"); + check("let x = 1; return x + arg0", "return 1 + arg0;"); + // check("let x = 1; return arg0 + x", "return arg0 + 1;"); + check("let x = 1; return x + fn()", "return 1 + fn();"); + check("let x = 1; return fn() + x", "let x = 1;\nreturn fn() + x;"); + check("let x = 1; return x + undef", "return 1 + undef;"); + check("let x = 1; return undef + x", "let x = 1;\nreturn undef + x;"); + + // Check substituting a value with side-effects into normal binary operators + check("let x = fn(); return x + 2", "return fn() + 2;"); + check("let x = fn(); return 2 + x", "return 2 + fn();"); + check("let x = fn(); return x + arg0", "return fn() + arg0;"); + check("let x = fn(); return arg0 + x", "let x = fn();\nreturn arg0 + x;"); + check("let x = fn(); return x + fn2()", "return fn() + fn2();"); + check( + "let x = fn(); return fn2() + x", + "let x = fn();\nreturn fn2() + x;", + ); + check("let x = fn(); return x + undef", "return fn() + undef;"); + check( + "let x = fn(); return undef + x", + "let x = fn();\nreturn undef + x;", + ); + + // Cannot substitute into mutating unary operators + check("let x = 1; ++x", "let x = 1;\n++x;"); + check("let x = 1; --x", "let x = 1;\n--x;"); + check("let x = 1; x++", "let x = 1;\nx++;"); + check("let x = 1; x--", "let x = 1;\nx--;"); + check("let x = 1; delete x", "let x = 1;\ndelete x;"); + + // Cannot substitute into mutating binary operators + check("let x = 1; x = 2", "let x = 1;\nx = 2;"); + check("let x = 1; x += 2", "let x = 1;\nx += 2;"); + check("let x = 1; x ||= 2", "let x = 1;\nx ||= 2;"); + + // Can substitute past mutating binary operators when the left operand has no side effects + // check("let x = 1; arg0 = x", "arg0 = 1;"); + // check("let x = 1; arg0 += x", "arg0 += 1;"); + // check("let x = 1; arg0 ||= x", "arg0 ||= 1;"); + // check("let x = fn(); arg0 = x", "arg0 = fn();"); + // check("let x = fn(); arg0 += x", "let x = fn();\narg0 += x;"); + // check("let x = fn(); arg0 ||= x", "let x = fn();\narg0 ||= x;"); + + // Cannot substitute past mutating binary operators when the left operand has side effects + check("let x = 1; y.z = x", "let x = 1;\ny.z = x;"); + check("let x = 1; y.z += x", "let x = 1;\ny.z += x;"); + check("let x = 1; y.z ||= x", "let x = 1;\ny.z ||= x;"); + check("let x = fn(); y.z = x", "let x = fn();\ny.z = x;"); + check("let x = fn(); y.z += x", "let x = fn();\ny.z += x;"); + check("let x = fn(); y.z ||= x", "let x = fn();\ny.z ||= x;"); + + // TODO: + // Can substitute code without side effects into branches + // check("let x = arg0; return x ? y : z;", "return arg0 ? y : z;"); + // check("let x = arg0; return arg1 ? x : y;", "return arg1 ? arg0 : y;"); + // check("let x = arg0; return arg1 ? y : x;", "return arg1 ? y : arg0;"); + // check("let x = arg0; return x || y;", "return arg0 || y;"); + // check("let x = arg0; return x && y;", "return arg0 && y;"); + // check("let x = arg0; return x ?? y;", "return arg0 ?? y;"); + // check("let x = arg0; return arg1 || x;", "return arg1 || arg0;"); + // check("let x = arg0; return arg1 && x;", "return arg1 && arg0;"); + // check("let x = arg0; return arg1 ?? x;", "return arg1 ?? arg0;"); + + // Can substitute code without side effects into branches past an expression with side effects + // check( + // "let x = arg0; return y ? x : z;", + // "let x = arg0;\nreturn y ? x : z;", + // ); + // check( + // "let x = arg0; return y ? z : x;", + // "let x = arg0;\nreturn y ? z : x;", + // ); + // check("let x = arg0; return (arg1 ? 1 : 2) ? x : 3;", "return arg0;"); + // check( + // "let x = arg0; return (arg1 ? 1 : 2) ? 3 : x;", + // "let x = arg0;\nreturn 3;", + // ); + // check( + // "let x = arg0; return (arg1 ? y : 1) ? x : 2;", + // "let x = arg0;\nreturn !arg1 || y ? x : 2;", + // ); + // check( + // "let x = arg0; return (arg1 ? 1 : y) ? x : 2;", + // "let x = arg0;\nreturn arg1 || y ? x : 2;", + // ); + // check( + // "let x = arg0; return (arg1 ? y : 1) ? 2 : x;", + // "let x = arg0;\nreturn !arg1 || y ? 2 : x;", + // ); + // check( + // "let x = arg0; return (arg1 ? 1 : y) ? 2 : x;", + // "let x = arg0;\nreturn arg1 || y ? 2 : x;", + // ); + // check("let x = arg0; return y || x;", "let x = arg0;\nreturn y || x;"); + // check("let x = arg0; return y && x;", "let x = arg0;\nreturn y && x;"); + // check("let x = arg0; return y ?? x;", "let x = arg0;\nreturn y ?? x;"); + + // Cannot substitute code with side effects into branches + check("let x = fn(); return x ? arg0 : y;", "return fn() ? arg0 : y;"); + check( + "let x = fn(); return arg0 ? x : y;", + "let x = fn();\nreturn arg0 ? x : y;", + ); + check( + "let x = fn(); return arg0 ? y : x;", + "let x = fn();\nreturn arg0 ? y : x;", + ); + check("let x = fn(); return x || arg0;", "return fn() || arg0;"); + check("let x = fn(); return x && arg0;", "return fn() && arg0;"); + check("let x = fn(); return x ?? arg0;", "return fn() ?? arg0;"); + check( + "let x = fn(); return arg0 || x;", + "let x = fn();\nreturn arg0 || x;", + ); + check( + "let x = fn(); return arg0 && x;", + "let x = fn();\nreturn arg0 && x;", + ); + check( + "let x = fn(); return arg0 ?? x;", + "let x = fn();\nreturn arg0 ?? x;", + ); + + // Test chaining + check( + "let x = fn(); let y = x[prop]; let z = y.val; throw z", + "throw fn()[prop].val;", + ); + check( + "let x = fn(), y = x[prop], z = y.val; throw z", + "throw fn()[prop].val;", + ); + + // Can substitute an initializer with side effects + check("let x = 0; let y = ++x; return y", "let x = 0;\nreturn ++x;"); + + // Can substitute an initializer without side effects past an expression without side effects + check( + "let x = 0; let y = x; return [x, y]", + "let x = 0;\nreturn [x, x];", + ); + + // TODO: merge s_local + // Cannot substitute an initializer with side effects past an expression without side effects + // check( + // "let x = 0; let y = ++x; return [x, y]", + // "let x = 0, y = ++x;\nreturn [x, y];", + // ); + + // Cannot substitute an initializer without side effects past an expression with side effects + // TODO: merge s_local + // check( + // "let x = 0; let y = {valueOf() { x = 1 }}; let z = x; return [y == 1, z]", + // "let x = 0, y = { valueOf() {\n x = 1;\n} }, z = x;\nreturn [y == 1, z];", + // ); + + // Cannot inline past a spread operator, since that evaluates code + check("let x = arg0; return [...x];", "return [...arg0];"); + check("let x = arg0; return [x, ...arg1];", "return [arg0, ...arg1];"); + check( + "let x = arg0; return [...arg1, x];", + "let x = arg0;\nreturn [...arg1, x];", + ); + // TODO: preserve call here + // check("let x = arg0; return arg1(...x);", "return arg1(...arg0);"); + // check( + // "let x = arg0; return arg1(x, ...arg1);", + // "return arg1(arg0, ...arg1);", + // ); + check( + "let x = arg0; return arg1(...arg1, x);", + "let x = arg0;\nreturn arg1(...arg1, x);", + ); + + // Test various statement kinds + // TODO: + // check("let x = arg0; arg1(x);", "arg1(arg0);"); + + check("let x = arg0; throw x;", "throw arg0;"); + check("let x = arg0; return x;", "return arg0;"); + check("let x = arg0; if (x) return 1;", "if (arg0)\n return 1;"); + check( + "let x = arg0; switch (x) { case 0: return 1; }", + "switch (arg0) {\n case 0:\n return 1;\n}", + ); + check( + "let x = arg0; let y = x; return y + y;", + "let y = arg0;\nreturn y + y;", + ); + + // Loops must not be substituted into because they evaluate multiple times + check( + "let x = arg0; do {} while (x);", + "let x = arg0;\ndo\n ;\nwhile (x);", + ); + + // TODO: convert while(x) to for (;x;) + check( + "let x = arg0; while (x) return 1;", + "let x = arg0;\nwhile (x)\n return 1;", + // "let x = arg0;\nfor (; x; )\n return 1;", + ); + check( + "let x = arg0; for (; x; ) return 1;", + "let x = arg0;\nfor (;x; )\n return 1;", + ); + + // Can substitute an expression without side effects into a branch due to optional chaining + // TODO: + // check("let x = arg0; return arg1?.[x];", "return arg1?.[arg0];"); + // check("let x = arg0; return arg1?.(x);", "return arg1?.(arg0);"); + + // Cannot substitute an expression with side effects into a branch due to optional chaining, + // since that would change the expression with side effects from being unconditionally + // evaluated to being conditionally evaluated, which is a behavior change + check( + "let x = fn(); return arg1?.[x];", + "let x = fn();\nreturn arg1?.[x];", + ); + check( + "let x = fn(); return arg1?.(x);", + "let x = fn();\nreturn arg1?.(x);", + ); + + // Can substitute an expression past an optional chaining operation, since it has side effects + check( + "let x = arg0; return arg1?.a === x;", + "let x = arg0;\nreturn arg1?.a === x;", + ); + check( + "let x = arg0; return arg1?.[0] === x;", + "let x = arg0;\nreturn arg1?.[0] === x;", + ); + check( + "let x = arg0; return arg1?.(0) === x;", + "let x = arg0;\nreturn arg1?.(0) === x;", + ); + check( + "let x = arg0; return arg1?.a[x];", + "let x = arg0;\nreturn arg1?.a[x];", + ); + check( + "let x = arg0; return arg1?.a(x);", + "let x = arg0;\nreturn arg1?.a(x);", + ); + // TODO: + // check( + // "let x = arg0; return arg1?.[a][x];", + // "let x = arg0;\nreturn arg1?.[a][x];", + // ); + check( + "let x = arg0; return arg1?.[a](x);", + "let x = arg0;\nreturn (arg1?.[a])(x);", + ); + check( + "let x = arg0; return arg1?.(a)[x];", + "let x = arg0;\nreturn (arg1?.(a))[x];", + ); + check( + "let x = arg0; return arg1?.(a)(x);", + "let x = arg0;\nreturn (arg1?.(a))(x);", + ); + + // Can substitute into an object as long as there are no side effects + // beforehand. Note that computed properties must call "toString()" which + // can have side effects. + check("let x = arg0; return {x};", "return { x: arg0 };"); + check( + "let x = arg0; return {x: y, y: x};", + "let x = arg0;\nreturn { x: y, y: x };", + ); + // TODO: + // check( + // "let x = arg0; return {x: arg1, y: x};", + // "return { x: arg1, y: arg0 };", + // ); + check("let x = arg0; return {[x]: 0};", "return { [arg0]: 0 };"); + check( + "let x = arg0; return {[y]: x};", + "let x = arg0;\nreturn { [y]: x };", + ); + check( + "let x = arg0; return {[arg1]: x};", + "let x = arg0;\nreturn { [arg1]: x };", + ); + // TODO: + // check( + // "let x = arg0; return {y() {}, x};", + // "return { y() {\n}, x: arg0 };", + // ); + check( + "let x = arg0; return {[y]() {}, x};", + "let x = arg0;\nreturn { [y]() {\n}, x };", + ); + check("let x = arg0; return {...x};", "return { ...arg0 };"); + check("let x = arg0; return {...x, y};", "return { ...arg0, y };"); + check("let x = arg0; return {x, ...y};", "return { x: arg0, ...y };"); + check( + "let x = arg0; return {...y, x};", + "let x = arg0;\nreturn { ...y, x };", + ); + + // TODO: + // Check substitutions into template literals + // check("let x = arg0; return `a${x}b${y}c`;", "return `a${arg0}b${y}c`;"); + // check( + // "let x = arg0; return `a${y}b${x}c`;", + // "let x = arg0;\nreturn `a${y}b${x}c`;", + // ); + // check( + // "let x = arg0; return `a${arg1}b${x}c`;", + // "return `a${arg1}b${arg0}c`;", + // ); + // check("let x = arg0; return x`y`;", "return arg0`y`;"); + // check( + // "let x = arg0; return y`a${x}b`;", + // "let x = arg0;\nreturn y`a${x}b`;", + // ); + // check("let x = arg0; return arg1`a${x}b`;", "return arg1`a${arg0}b`;"); + // check("let x = 'x'; return `a${x}b`;", "return `axb`;"); + + // Check substitutions into import expressions + // TODO: + // check("let x = arg0; return import(x);", "return import(arg0);"); + // check( + // "let x = arg0; return [import(y), x];", + // "let x = arg0;\nreturn [import(y), x];", + // ); + // check( + // "let x = arg0; return [import(arg1), x];", + // "return [import(arg1), arg0];", + // ); + + // Check substitutions into await expressions + check( + "return async () => { let x = arg0; await x; };", + "return async () => {\n await arg0;\n};", + ); + + // TODO: combine with comma operator + // check( + // "return async () => { let x = arg0; await y; return x; };", + // "return async () => {\n let x = arg0;\n return await y, x;\n};", + // ); + // check( + // "return async () => { let x = arg0; await arg1; return x; };", + // "return async () => {\n let x = arg0;\n return await arg1, x;\n};", + // ); + + // Check substitutions into yield expressions + check( + "return function* () { let x = arg0; yield x; };", + "return function* () {\n yield arg0;\n};", + ); + // TODO: combine with comma operator + // check( + // "return function* () { let x = arg0; yield; return x; };", + // "return function* () {\n let x = arg0;\n yield ; \n return x;\n};", + // ); + // check( + // "return function* () { let x = arg0; yield y; return x; };", + // "return function* () {\n let x = arg0;\n return yield y, x;\n};", + // ); + // check( + // "return function* () { let x = arg0; yield arg1; return x; };", + // "return function* () {\n let x = arg0;\n return yield arg1, x;\n};", + // ); + + // Cannot substitute into call targets when it would change "this" + check("let x = arg0; x()", "arg0();"); + // check("let x = arg0; (0, x)()", "arg0();"); + check("let x = arg0.foo; x.bar()", "arg0.foo.bar();"); + check("let x = arg0.foo; x[bar]()", "arg0.foo[bar]();"); + check("let x = arg0.foo; x()", "let x = arg0.foo;\nx();"); + check("let x = arg0[foo]; x()", "let x = arg0[foo];\nx();"); + check("let x = arg0?.foo; x()", "let x = arg0?.foo;\nx();"); + check("let x = arg0?.[foo]; x()", "let x = arg0?.[foo];\nx();"); + // check("let x = arg0.foo; (0, x)()", "let x = arg0.foo;\nx();"); + // check("let x = arg0[foo]; (0, x)()", "let x = arg0[foo];\nx();"); + // check("let x = arg0?.foo; (0, x)()", "let x = arg0?.foo;\nx();"); + // check("let x = arg0?.[foo]; (0, x)()", "let x = arg0?.[foo];\nx();"); + }); + it("constant folding", () => { expectPrinted("1 && 2", "2"); expectPrinted("1 || 2", "1"); |