v8/test/mjsunit/harmony/function-tostring.js

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Implement new Function.prototype.toString --harmony-function-tostring For functions declared in source code, the .toString() representation will be an excerpt of the source code. * For functions declared with the "function" keyword, the excerpt starts at the "function" or "async" keyword and ends at the final "}". The previous behavior would start the excerpt at the "(" of the parameter list, and prepend a canonical `"function " + name` or similar, which would discard comments and formatting surrounding the function's name. Anonymous functions declared as function expressions no longer get the name "anonymous" in their toString representation. * For methods, the excerpt starts at the "get", "set", "*" (for generator methods), or property name, whichever comes first. Previously, the toString representation for methods would use a canonical prefix before the "(" of the parameter list. Note that any "static" keyword is omitted. * For arrow functions and class declarations, the excerpt is unchanged. For functions created with the Function, GeneratorFunction, or AsyncFunction constructors: * The string separating the parameter text and body text is now "\n) {\n", where previously it was "\n/*``*/) {\n" or ") {\n". * At one point, newline normalization was required by the spec here, but that was removed from the spec, and so this CL does not do it. Included in this CL is a fix for CreateDynamicFunction parsing. ')' and '`' characters in the parameter string are no longer disallowed, and Function("a=function(", "}){") is no longer allowed. BUG=v8:4958, v8:4230 Review-Url: https://codereview.chromium.org/2156303002 Cr-Commit-Position: refs/heads/master@{#43262}
2017-02-16 20:19:24 +00:00
// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --harmony-function-tostring
var prefix = "/*before*/";
var suffix = "/*after*/";
function checkStringRepresentation(f, source) {
assertEquals(typeof f, "function");
assertEquals(source, f.toString());
}
function testDeclaration(source) {
// this eval should define a local variable f that is a function
eval(prefix + source + suffix);
checkStringRepresentation(f, source);
}
testDeclaration( "function f(){}");
testDeclaration( "function*f(){}");
testDeclaration("async function f(){}");
testDeclaration( "function/*A*/ f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testDeclaration( "function/*A*/*f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testDeclaration("async/*Z*/function/*A*/ f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testDeclaration( "function \t f \n ( \r a \r\n,\n\r b ) {'\u2654'}");
testDeclaration( "function \t *f \n ( \r a \r\n,\n\r b ) { }");
testDeclaration( "function *\t f \n ( \r a \r\n,\n\r b ) { }");
testDeclaration("async \t function f \n ( \r a \r\n,\n\r b ) { }");
function testExpression(source) {
// this eval should return a function
var f = eval("(" + prefix + source + suffix + ")");
checkStringRepresentation(f, source);
}
testExpression( "function (){}");
testExpression( "function f(){}");
testExpression( "function* (){}");
testExpression( "function*f(){}");
testExpression("async function (){}");
testExpression("async function f(){}");
testExpression( "function/*A*/ /*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testExpression( "function/*A*/ f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testExpression( "function/*A*/* /*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testExpression( "function/*A*/*f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testExpression("async/*Z*/function/*A*/ f/*B*/(/*C*/a/*D*/,/*E*/b/*G*/)/*H*/{/*I*/}");
testExpression( "function \t \n ( \r a \r\n,\n\r b ) { }");
testExpression( "function \t f \n ( \r a \r\n,\n\r b ) { }");
testExpression( "function \t * \n ( \r a \r\n,\n\r b ) { }");
testExpression( "function \t *f \n ( \r a \r\n,\n\r b ) { }");
testExpression( "function *\t \n ( \r a \r\n,\n\r b ) { }");
testExpression( "function *\t f \n ( \r a \r\n,\n\r b ) { }");
testExpression("async \t function \n ( \r a \r\n,\n\r b ) { }");
testExpression( "(/*A*/ /*B*/ /*C*/ /*D*/ /*E*/ /*F*/)/*G*/=>/*H*/0");
testExpression( "a/*B*/ /*C*/ /*D*/ /*E*/ /*F*/ /*G*/=>/*H*/{}");
testExpression( "(/*A*/a/*B*/ /*C*/ /*D*/ /*E*/ /*F*/)/*G*/=>/*H*/0");
testExpression( "(/*A*/a/*B*/,/*C*/b/*D*/,/*E*/c/*F*/)/*G*/=>/*H*/{}");
testExpression("async (/*A*/ /*B*/ /*C*/ /*D*/ /*E*/ /*F*/)/*G*/=>/*H*/0");
testExpression("async a/*B*/ /*C*/ /*D*/ /*E*/ /*F*/ /*G*/=>/*H*/{}");
testExpression("async (/*A*/a/*B*/ /*C*/ /*D*/ /*E*/ /*F*/)/*G*/=>/*H*/0");
testExpression("async (/*A*/a/*B*/,/*C*/b/*D*/,/*E*/c/*F*/)/*G*/=>/*H*/{}");
function testSimpleMethod(source) {
// the source should define a method f
// object method
var f = eval("({" + prefix + source + suffix + "}.f)");
checkStringRepresentation(f, source);
// nonstatic class method
var f = eval("new class{" + prefix + source + suffix + "}().f");
checkStringRepresentation(f, source);
// static class method
var f = eval("(class{static" + prefix + source + suffix + "}).f");
checkStringRepresentation(f, source);
}
testSimpleMethod("f(){}");
testSimpleMethod("*f(){}");
testSimpleMethod("async f(){}");
testSimpleMethod("f \t (){}");
testSimpleMethod("* \tf(){}");
testSimpleMethod("async \t f (){}");
function testAccessorMethod(source, getOrSet) {
// the source should define a getter or setter method
// object method
var f = Object.getOwnPropertyDescriptor(eval("({" + prefix + source + suffix + "})"), "f")[getOrSet];
checkStringRepresentation(f, source);
// nonstatic class method
var f = Object.getOwnPropertyDescriptor(eval("(class{" + prefix + source + suffix + "})").prototype, "f")[getOrSet];
// static class method
var f = Object.getOwnPropertyDescriptor(eval("(class{static" + prefix + source + suffix + "})"), "f")[getOrSet];
checkStringRepresentation(f, source);
}
testAccessorMethod("get f( ){}", "get");
testAccessorMethod("set f(a){}", "set");
testAccessorMethod("get/*A*/f/*B*/(/*C*/ /*D*/)/*E*/{/*F*/}", "get");
testAccessorMethod("set/*A*/f/*B*/(/*C*/a/*D*/)/*E*/{/*F*/}", "set");
const GeneratorFunction = function*(){}.constructor;
const AsyncFunction = async function(){}.constructor;
function testDynamicFunction(...args) {
var P = args.slice(0, args.length - 1).join(",");
var bodyText = args.length > 0 ? args[args.length - 1] : "";
var source = " anonymous(" + P + "\n) {\n" + bodyText + "\n}";
checkStringRepresentation( Function(...args), "function" + source);
checkStringRepresentation(GeneratorFunction(...args), "function*" + source);
checkStringRepresentation( AsyncFunction(...args), "async function" + source);
}
testDynamicFunction();
testDynamicFunction(";");
testDynamicFunction("return");
testDynamicFunction("a", "return a");
testDynamicFunction("a", "b", "return a");
testDynamicFunction("a, b", "return a");
testDynamicFunction("a,/*A*/b", "return a");
testDynamicFunction("/*A*/a,b", "return a");
testDynamicFunction("a,b", "return a/*A*/");