Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 | 1x 1x 1x 1x 1x 1x 1x 23x 23x 334x 16x 318x 23x 295x 10x 23x 23x 23x 3x 20x 19x 1x 1x 1x 23x 16x 16x 16x 16x 16x 10x 10x 4x 4x 2x 2x 6x 6x 3x 3x 6x 3x 10x 10x 10x 10x 23x 14x 14x 8x 8x 2x 2x 6x 8x 4x 8x 6x 6x 6x 4x 4x 2x 6x 6x 26x 26x 22x 4x 4x 26x 6x 9x 9x 9x 6x 6x 3x 9x 6x 9x 3x 3x 9x 9x 6x 3x 9x 23x 23x 34x 34x 80x 28x 52x 48x 17x 31x 4x 4x 34x 20x 20x 265x 221x 39x 182x 182x 24x 20x | // See https://github.com/babel/minify/tree/master/packages/babel-plugin-minify-constant-folding
const fs = require("fs");
const deb = require('../src/deb.js');
const escodegen = require("escodegen");
const espree = require("espree");
const estraverse = require("estraverse");
"use strict";
module.exports = constantFolding;
/**
* A function that creates the AST of the given code and modifies it for
* allowing the use of array and strings methods.
*
* @param {string} code A string with the js program code.
* @param {string} pattern The pattern (other parameters).
* @return {string} Returns a string with the output in AST format or JS
* format.
*/
function constantFolding(code, pattern) {
const t = espree.parse(code, { ecmaVersion: 6, loc: false });
estraverse.traverse(t, {
leave: function (n, p) {
if (n.type == "BinaryExpression" && n.left.type == "Literal" && n.right.type == "Literal") {
replaceByLiteral(n);
}
else if (n.type == "CallExpression") {
replaceByCallExpression(n);
}
else if (n.type == "MemberExpression" && p.type != "CallExpression") {
replaceByMemberExpression(n);
}
},
});
let result = "";
let c = escodegen.generate(t);
if (pattern == "--ast" || pattern == "-a") {
//result = 'AST Json code: \n\n';
result += JSON.stringify(t, 0, 2);
}
else if (pattern == "--js" || pattern == "-j") {
//result = '\n\n---\n\n JavaScript code:\n\n';
result += generateOutput(c);
}
else Eif (pattern == "--deb" || pattern == "-d") {
result += generateOutput(c);
deb(t);
}
else {
result = 'AST Json code: \n\n';
result += JSON.stringify(t, 0, 2);
result += '\n\n---\n\n JavaScript code:\n\n';
result += generateOutput(c);
}
return result;
}
/**
* Modifies the literal node for computing the operations and apply constant
* folding.
*
* @param {<type>} node The node.
*/
function replaceByLiteral(node) {
node.type = "Literal";
node.value = eval(`${node.left.raw} ${node.operator} ${node.right.raw}`);
node.raw = String(node.value);
delete node.left;
delete node.right;
}
/**
* Modifies the member expression node for allowing use for array and strings
* methods.
*
* @param {Node} node The node.
*/
function replaceByMemberExpression(node) {
node.type = "Literal";
// Array methods
if (node.object.type == "ArrayExpression") {
var arr = generateArray(node.object.elements);
if (node.property.type == "Literal") {
node.value = eval(`[${arr}][${node.property.value}]`);
}
else {
node.value = eval(`[${arr}].${node.property.name}`);
}
}
// String and number methods
else Eif (node.object.type == "Literal") {
if (node.property.type == "Literal") {
node.value = eval(`"${node.object.value}"[${node.property.value}]`);
}
else {
node.value = eval(`"${node.object.value}".${node.property.name}`);
}
// Add quotes to strings
if (typeof(node.value) != "number") {
node.value = "\"" + node.value + "\"";
}
}
node.raw = String(node.value);
node.computed = true;
delete node.object;
delete node.property;
}
/**
* Modifies the call expression node for allowing use for array and strings
* methods.
*
* @param {Node} node The node.
*/
function replaceByCallExpression(node) {
// Array methods
if (node.callee.object.type == "ArrayExpression") {
var arr = generateArray(node.callee.object.elements);
if (node.callee.property.name == "join" || node.callee.property.name == "shift" || node.callee.property.name == "pop") {
node.type = "Literal";
if (node.arguments.length > 0) {
var args = generateArray(node.arguments);
node.value = eval(`[${arr}].${node.callee.property.name}(${args})`);
}
else {
node.value = eval(`[${arr}].${node.callee.property.name}()`);
}
if (node.callee.property.name === "join") {
node.value = "\"" + node.value + "\"";
}
node.raw = String(node.value);
}
else {
node.type = "ArrayExpression";
var result = "";
if (node.arguments.length > 0) {
var args = generateArray(node.arguments)
result = eval(`[${arr}].${node.callee.property.name}(${args})`);
}
else {
result = eval(`[${arr}].${node.callee.property.name}()`);
}
var tmp = new Array();
for (var i = 0; i < result.length; i++) {
var newNode = Object.assign({} , node.callee.object.elements[0]);
if (newNode.hasOwnProperty("name")) {
newNode.name = result[i];
}
else Eif (newNode.hasOwnProperty("value")) {
newNode.value = result[i];
}
tmp.push(newNode);
}
node.elements = tmp;
}
}
// String and number methods
else Eif (node.callee.object.type == "Literal") {
node.type = "Literal";
if (node.arguments.length > 0) {
var args = generateArray(node.arguments);
node.value = eval(`"${node.callee.object.value}".${node.callee.property.name}(${args})`);
}
else {
node.value = eval(`"${node.callee.object.value}".${node.callee.property.name}()`);
}
// Add quotes in string methods
if (typeof(node.value) !== "number" && node.callee.property.name !== 'split') {
node.value = "\"" + node.value + "\"";
}
if (typeof(node.value) !== "number" && node.callee.property.name === 'split') {
let addQuotes = "";
for (let i = 0; i < node.value.length; i++) {
addQuotes += "\"" + node.value[i] + "\""
if (i < node.value.length - 1) {
addQuotes += ", ";
}
}
node.value = addQuotes;
}
node.raw = String(node.value);
}
delete node.callee;
delete node.arguments;
}
/**
* Receives a node and generates an array from the elements of that node.
*
* @param {Node} node The node.
* @return {Array} Array with the elements of the node.
*/
function generateArray (node) {
var arr = new Array();
for (var i in node) {
if (node[i].type === "Identifier") {
arr.push(`"${node[i].name}"`);
}
else if (node[i].type === "Literal") {
if (typeof(node[i].value) === "string") {
arr.push(`"${node[i].value}"`);
}
else {
arr.push(`${node[i].value}`);
}
}
else Eif (node[i].type === "ArrayExpression") {
arr.push(generateArray(node[i].elements));
}
else {
console.log("Error, not valid expresion in generateArray");
}
}
return arr;
}
/**
* Modifies the JS output for printing it in one line and without many spaces.
*
* @param {string} code The code
* @return {string} The output with better format.
*/
function generateOutput(code) {
let result = "";
for (let i = 0; i < code.length; i++) {
if (code[i] !== '\n' && code[i] !== '\'') {
if (code[i] === ' ' && code[i - 1] === ' ') {
continue;
}
result += code[i];
if (code[i] === ';') {
result += '\n';
}
}
}
return result;
}
// const input = `
// var f = 3+null;
// var e = 4 | 3;
// var d = 3+"c";
// var b = 9 +1;
// var a = 2+3*5+b;
// [a, b, c].concat([d, e], f, g, [h]);
// ["a", "b", "c"].join();
// ["a", "b", "c"].join('@');
// [1, 2, 3].length;
// [1, 2, 3][2-1];
// [1, 2, 3].shift();
// [1, 2, 3].slice(0, 1+1);
// [a, b, c].pop();
// [a, b, c].reverse();
// "abc"[0];
// "abc".charAt();
// "abc".charAt(1);
// "abc".length;
// "a,b,c".split(",");
// (100 + 23).toString();
// `;
// console.log(constantFolding(input, "--js")); |