1211 lines
36 KiB
JavaScript
1211 lines
36 KiB
JavaScript
"use strict";
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var _slicedToArray = function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; }();
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function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
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module.exports = function (_ref) {
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var t = _ref.types;
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var flipExpressions = require("babel-helper-flip-expressions")(t);
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var toMultipleSequenceExpressions = require("babel-helper-to-multiple-sequence-expressions")(t);
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var ifStatement = require("./if-statement")(t);
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var conditionalExpression = require("./conditional-expression")(t);
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var logicalExpression = require("./logical-expression")(t);
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var assignmentExpression = require("./assignment-expression")(t);
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var VOID_0 = t.unaryExpression("void", t.numericLiteral(0), true);
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var condExprSeen = Symbol("condExprSeen");
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var seqExprSeen = Symbol("seqExprSeen");
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var shouldRevisit = Symbol("shouldRevisit");
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return {
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name: "minify-simplify",
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visitor: {
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Statement: {
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exit(path) {
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if (path.node[shouldRevisit]) {
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delete path.node[shouldRevisit];
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path.visit();
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}
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}
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},
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// CallExpression(path) {
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// const { node } = path;
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/* (function() {})() -> !function() {}()
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There is a bug in babel in printing this. Disabling for now.
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if (t.isFunctionExpression(node.callee) &&
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(t.isExpressionStatement(parent) ||
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(t.isSequenceExpression(parent) && parent.expressions[0] === node))
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) {
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path.replaceWith(
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t.callExpression(
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t.unaryExpression("!", node.callee, true),
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node.arguments
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)
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);
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return;
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}*/
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// },
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UnaryExpression: {
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enter: [
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// Demorgans.
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function (path) {
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var node = path.node;
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if (node.operator !== "!" || flipExpressions.hasSeen(node)) {
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return;
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}
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var expr = node.argument;
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// We need to make sure that the return type will always be boolean.
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if (!(t.isLogicalExpression(expr) || t.isConditionalExpression(expr) || t.isBinaryExpression(expr))) {
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return;
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}
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if (t.isBinaryExpression(expr) && t.COMPARISON_BINARY_OPERATORS.indexOf(expr.operator) === -1) {
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return;
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}
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if (flipExpressions.shouldFlip(expr, 1)) {
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var newNode = flipExpressions.flip(expr);
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path.replaceWith(newNode);
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}
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},
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// !(a, b, c) -> a, b, !c
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function (path) {
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var node = path.node;
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if (node.operator !== "!") {
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return;
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}
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if (!t.isSequenceExpression(node.argument)) {
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return;
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}
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var seq = node.argument.expressions;
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var expr = seq[seq.length - 1];
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seq[seq.length - 1] = t.unaryExpression("!", expr, true);
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path.replaceWith(node.argument);
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},
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// !(a ? b : c) -> a ? !b : !c
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function (path) {
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var node = path.node;
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if (node.operator !== "!") {
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return;
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}
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if (!t.isConditional(node.argument)) {
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return;
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}
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var cond = node.argument;
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cond.alternate = t.unaryExpression("!", cond.alternate, true);
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cond.consequent = t.unaryExpression("!", cond.consequent, true);
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path.replaceWith(node.argument);
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}]
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},
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LogicalExpression: {
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exit: logicalExpression.simplifyPatterns
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},
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AssignmentExpression: assignmentExpression.simplify,
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ConditionalExpression: {
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enter: [
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// !foo ? 'foo' : 'bar' -> foo ? 'bar' : 'foo'
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// foo !== 'lol' ? 'foo' : 'bar' -> foo === 'lol' ? 'bar' : 'foo'
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function flipIfOrConditional(path) {
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var node = path.node;
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if (!path.get("test").isLogicalExpression()) {
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flipNegation(node);
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return;
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}
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if (flipExpressions.shouldFlip(node.test)) {
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node.test = flipExpressions.flip(node.test);
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var _ref2 = [node.consequent, node.alternate];
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node.alternate = _ref2[0];
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node.consequent = _ref2[1];
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}
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}, conditionalExpression.simplifyPatterns],
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exit: [
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// a ? x = foo : b ? x = bar : x = baz;
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// x = a ? foo : b ? bar : baz;
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function (topPath) {
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if (!topPath.parentPath.isExpressionStatement() && !topPath.parentPath.isSequenceExpression()) {
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return;
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}
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var mutations = [];
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var firstLeft = null;
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var operator = null;
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function visit(path) {
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if (path.isConditionalExpression()) {
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var _bail = visit(path.get("consequent"));
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if (_bail) {
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return true;
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}
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_bail = visit(path.get("alternate"));
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return _bail;
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}
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if (operator == null) {
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operator = path.node.operator;
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} else if (path.node.operator !== operator) {
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return true;
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}
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if (!path.isAssignmentExpression() || !(path.get("left").isIdentifier() || path.get("left").isMemberExpression())) {
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return true;
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}
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var left = path.get("left").node;
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if (firstLeft == null) {
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firstLeft = left;
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} else if (!t.isNodesEquivalent(left, firstLeft)) {
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return true;
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}
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mutations.push(function () {
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return path.replaceWith(path.get("right").node);
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});
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}
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var bail = visit(topPath);
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if (bail) {
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return;
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}
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mutations.forEach(function (f) {
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return f();
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});
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topPath.replaceWith(t.assignmentExpression(operator, firstLeft, topPath.node));
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},
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// bar ? void 0 : void 0
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// (bar, void 0)
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// TODO: turn this into general equiv check
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function (path) {
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var node = path.node;
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if (isVoid0(node.consequent) && isVoid0(node.alternate)) {
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path.replaceWith(t.sequenceExpression([path.node.test, VOID_0]));
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}
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},
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// bar ? void 0 : foo ? void 0 : <etc>
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// bar || foo : void 0
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// TODO: turn this into general equiv check
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function (path) {
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var node = path.node;
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if (node[condExprSeen] || !isVoid0(node.consequent)) {
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return;
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}
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node[condExprSeen] = true;
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var tests = [node.test];
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var mutations = [];
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var alt = void 0;
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var _loop = function _loop(next) {
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next.node[condExprSeen] = true;
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alt = next.node.alternate;
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if (isVoid0(next.node.consequent)) {
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tests.push(next.node.test);
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mutations.push(function () {
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return next.remove();
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});
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} else {
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alt = next.node;
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return "break";
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}
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};
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for (var next = path.get("alternate"); next.isConditionalExpression(); next = next.get("alternate")) {
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var _ret = _loop(next);
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if (_ret === "break") break;
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}
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if (tests.length === 1) {
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return;
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}
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var test = tests.reduce(function (expr, curTest) {
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return t.logicalExpression("||", expr, curTest);
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});
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path.replaceWith(t.conditionalExpression(test, VOID_0, alt));
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}]
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},
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// concat
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VariableDeclaration: {
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enter: [
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// Put vars with no init at the top.
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function (path) {
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var node = path.node;
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if (node.declarations.length < 2) {
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return;
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}
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var inits = [];
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var empty = [];
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var _iteratorNormalCompletion = true;
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var _didIteratorError = false;
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var _iteratorError = undefined;
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try {
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for (var _iterator = node.declarations[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
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var decl = _step.value;
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if (!decl.init) {
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empty.push(decl);
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} else {
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inits.push(decl);
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}
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}
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// This is based on exprimintation but there is a significant
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// imrpovement when we place empty vars at the top in smaller
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// files. Whereas it hurts in larger files.
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} catch (err) {
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_didIteratorError = true;
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_iteratorError = err;
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} finally {
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try {
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if (!_iteratorNormalCompletion && _iterator.return) {
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_iterator.return();
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}
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} finally {
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if (_didIteratorError) {
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throw _iteratorError;
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}
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}
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}
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if (this.fitsInSlidingWindow) {
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node.declarations = empty.concat(inits);
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} else {
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node.declarations = inits.concat(empty);
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}
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}]
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},
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Function: {
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exit(path) {
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earlyReturnTransform(path);
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if (!path.node[shouldRevisit]) {
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return;
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}
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delete path.node[shouldRevisit];
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path.visit();
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}
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},
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For: {
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enter: earlyContinueTransform,
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exit: earlyContinueTransform
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},
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ForStatement: {
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// Merge previous expressions in the init part of the for.
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enter(path) {
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var node = path.node;
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if (!path.inList || node.init && !t.isExpression(node.init)) {
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return;
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}
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var prev = path.getSibling(path.key - 1);
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var consumed = false;
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if (prev.isVariableDeclaration()) {
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var referencedOutsideLoop = false;
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// we don't care if vars are referenced outside the loop as they are fn scope
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if (prev.node.kind === "let" || prev.node.kind === "const") {
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var ids = Object.keys(prev.getBindingIdentifiers());
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idloop: for (var i = 0; i < ids.length; i++) {
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var binding = prev.scope.bindings[ids[i]];
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// TODO
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// Temporary Fix
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// if there is no binding, we assume it is referenced outside
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// and deopt to avoid bugs
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if (!binding) {
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referencedOutsideLoop = true;
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break idloop;
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}
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var refs = binding.referencePaths;
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for (var j = 0; j < refs.length; j++) {
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if (!isAncestor(path, refs[j])) {
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referencedOutsideLoop = true;
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break idloop;
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}
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}
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}
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}
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if (!node.init && !referencedOutsideLoop) {
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node.init = prev.node;
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consumed = true;
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}
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} else if (prev.isExpressionStatement()) {
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var expr = prev.node.expression;
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if (node.init) {
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if (t.isSequenceExpression(expr)) {
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expr.expressions.push(node.init);
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node.init = expr;
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} else {
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node.init = t.sequenceExpression([expr, node.init]);
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}
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} else {
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node.init = expr;
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}
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consumed = true;
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}
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if (consumed) {
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prev.remove();
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}
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},
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exit(path) {
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var node = path.node;
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if (!node.test) {
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return;
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}
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if (!path.get("body").isBlockStatement()) {
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var bodyNode = path.get("body").node;
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if (!t.isIfStatement(bodyNode)) {
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return;
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}
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if (t.isBreakStatement(bodyNode.consequent, { label: null })) {
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node.test = t.logicalExpression("&&", node.test, t.unaryExpression("!", bodyNode.test, true));
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node.body = bodyNode.alternate || t.emptyStatement();
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return;
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}
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if (t.isBreakStatement(bodyNode.alternate, { label: null })) {
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node.test = t.logicalExpression("&&", node.test, bodyNode.test);
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node.body = bodyNode.consequent || t.emptyStatement();
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return;
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}
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return;
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}
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var statements = node.body.body;
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var exprs = [];
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var ifStatement = null;
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var breakAt = null;
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var i = 0;
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for (var statement; statement = statements[i]; i++) {
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if (t.isIfStatement(statement)) {
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if (t.isBreakStatement(statement.consequent, { label: null })) {
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ifStatement = statement;
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breakAt = "consequent";
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} else if (t.isBreakStatement(statement.alternate, { label: null })) {
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ifStatement = statement;
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breakAt = "alternate";
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}
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break;
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}
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// A statement appears before the break statement then bail.
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if (!t.isExpressionStatement(statement)) {
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return;
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}
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exprs.push(statement.expression);
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}
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if (!ifStatement) {
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return;
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}
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var rest = [];
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if (breakAt === "consequent") {
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if (t.isBlockStatement(ifStatement.alternate)) {
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rest.push.apply(rest, _toConsumableArray(ifStatement.alternate.body));
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} else if (ifStatement.alternate) {
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rest.push(ifStatement.alternate);
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}
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} else {
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if (t.isBlockStatement(ifStatement.consequent)) {
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rest.push.apply(rest, _toConsumableArray(ifStatement.consequent.body));
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} else if (ifStatement.consequent) {
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rest.push(ifStatement.consequent);
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}
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}
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rest.push.apply(rest, _toConsumableArray(statements.slice(i + 1)));
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var test = breakAt === "consequent" ? t.unaryExpression("!", ifStatement.test, true) : ifStatement.test;
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var expr = void 0;
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if (exprs.length === 1) {
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expr = t.sequenceExpression([exprs[0], test]);
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} else if (exprs.length) {
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exprs.push(test);
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expr = t.sequenceExpression(exprs);
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} else {
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expr = test;
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}
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node.test = t.logicalExpression("&&", node.test, expr);
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if (rest.length === 1) {
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node.body = rest[0];
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} else if (rest.length) {
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node.body = t.blockStatement(rest);
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} else {
|
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node.body = t.emptyStatement();
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}
|
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}
|
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},
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|
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Program(path) {
|
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// An approximation of the resultant gzipped code after minification
|
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this.fitsInSlidingWindow = path.getSource().length / 10 < 33000;
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|
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var node = path.node;
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|
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var statements = toMultipleSequenceExpressions(node.body);
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if (!statements.length) {
|
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return;
|
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}
|
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node.body = statements;
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},
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BlockStatement: {
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enter(path) {
|
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var node = path.node,
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parent = path.parent;
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|
|
|
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var top = [];
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var bottom = [];
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|
|
|
for (var i = 0; i < node.body.length; i++) {
|
|
var bodyNode = node.body[i];
|
|
if (t.isFunctionDeclaration(bodyNode)) {
|
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top.push(bodyNode);
|
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} else {
|
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bottom.push(bodyNode);
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}
|
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}
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|
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var statements = top.concat(toMultipleSequenceExpressions(bottom));
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|
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if (!statements.length) {
|
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return;
|
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}
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|
|
|
if (statements.length > 1 || needsBlock(node, parent) || node.directives) {
|
|
node.body = statements;
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return;
|
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}
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|
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if (statements.length) {
|
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path.replaceWith(statements[0]);
|
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return;
|
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}
|
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},
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|
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exit(path) {
|
|
var node = path.node,
|
|
parent = path.parent;
|
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|
|
|
|
if (t.isArrowFunctionExpression(parent) && node.body.length === 1 && t.isReturnStatement(node.body[0]) && node.body[0].argument !== null) {
|
|
path.replaceWith(node.body[0].argument);
|
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return;
|
|
}
|
|
|
|
if (needsBlock(node, parent)) {
|
|
return;
|
|
}
|
|
|
|
if (node.body.length === 1) {
|
|
path.get("body")[0].inList = false;
|
|
path.replaceWith(node.body[0]);
|
|
return;
|
|
}
|
|
|
|
if (node.body.length === 0) {
|
|
path.replaceWith(t.emptyStatement());
|
|
return;
|
|
}
|
|
|
|
// Check if oppurtinties to merge statements are available.
|
|
var statements = node.body;
|
|
if (!statements.length) {
|
|
return;
|
|
}
|
|
|
|
var _iteratorNormalCompletion2 = true;
|
|
var _didIteratorError2 = false;
|
|
var _iteratorError2 = undefined;
|
|
|
|
try {
|
|
for (var _iterator2 = statements[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
|
|
var statement = _step2.value;
|
|
|
|
if (!t.isExpressionStatement(statement)) {
|
|
return;
|
|
}
|
|
}
|
|
} catch (err) {
|
|
_didIteratorError2 = true;
|
|
_iteratorError2 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion2 && _iterator2.return) {
|
|
_iterator2.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError2) {
|
|
throw _iteratorError2;
|
|
}
|
|
}
|
|
}
|
|
|
|
path.visit();
|
|
}
|
|
},
|
|
|
|
ThrowStatement: createPrevExpressionEater("throw"),
|
|
|
|
// Try to merge previous statements into a sequence
|
|
ReturnStatement: {
|
|
enter: [createPrevExpressionEater("return"),
|
|
|
|
// Remove return if last statement with no argument.
|
|
// Replace return with `void` argument with argument.
|
|
function (path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (!path.parentPath.parentPath.isFunction() || path.getSibling(path.key + 1).node) {
|
|
return;
|
|
}
|
|
|
|
if (!node.argument) {
|
|
path.remove();
|
|
return;
|
|
}
|
|
|
|
if (t.isUnaryExpression(node.argument, { operator: "void" })) {
|
|
path.replaceWith(node.argument.argument);
|
|
}
|
|
}]
|
|
},
|
|
|
|
// turn blocked ifs into single statements
|
|
IfStatement: {
|
|
exit: [ifStatement.mergeNestedIfs, ifStatement.simplify, ifStatement.switchConsequent, ifStatement.conditionalReturnToGuards, createPrevExpressionEater("if")]
|
|
},
|
|
|
|
WhileStatement(path) {
|
|
var node = path.node;
|
|
|
|
path.replaceWith(t.forStatement(null, node.test, null, node.body));
|
|
},
|
|
|
|
ForInStatement: createPrevExpressionEater("for-in"),
|
|
|
|
// Flatten sequence expressions.
|
|
SequenceExpression: {
|
|
exit(path) {
|
|
if (path.node[seqExprSeen]) {
|
|
return;
|
|
}
|
|
|
|
function flatten(node) {
|
|
node[seqExprSeen] = true;
|
|
var ret = [];
|
|
var _iteratorNormalCompletion3 = true;
|
|
var _didIteratorError3 = false;
|
|
var _iteratorError3 = undefined;
|
|
|
|
try {
|
|
for (var _iterator3 = node.expressions[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) {
|
|
var n = _step3.value;
|
|
|
|
if (t.isSequenceExpression(n)) {
|
|
ret.push.apply(ret, _toConsumableArray(flatten(n)));
|
|
} else {
|
|
ret.push(n);
|
|
}
|
|
}
|
|
} catch (err) {
|
|
_didIteratorError3 = true;
|
|
_iteratorError3 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion3 && _iterator3.return) {
|
|
_iterator3.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError3) {
|
|
throw _iteratorError3;
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
path.node.expressions = flatten(path.node);
|
|
}
|
|
},
|
|
|
|
SwitchCase(path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (!node.consequent.length) {
|
|
return;
|
|
}
|
|
|
|
node.consequent = toMultipleSequenceExpressions(node.consequent);
|
|
},
|
|
|
|
SwitchStatement: {
|
|
exit: [
|
|
// Convert switch statements with all returns in their cases
|
|
// to return conditional.
|
|
function (path) {
|
|
var node = path.node;
|
|
|
|
// Need to be careful of side-effects.
|
|
|
|
if (!t.isIdentifier(node.discriminant)) {
|
|
return;
|
|
}
|
|
|
|
if (!node.cases.length) {
|
|
return;
|
|
}
|
|
|
|
var consTestPairs = [];
|
|
var fallThru = [];
|
|
var defaultRet = void 0;
|
|
var _iteratorNormalCompletion4 = true;
|
|
var _didIteratorError4 = false;
|
|
var _iteratorError4 = undefined;
|
|
|
|
try {
|
|
for (var _iterator4 = node.cases[Symbol.iterator](), _step4; !(_iteratorNormalCompletion4 = (_step4 = _iterator4.next()).done); _iteratorNormalCompletion4 = true) {
|
|
var switchCase = _step4.value;
|
|
|
|
if (switchCase.consequent.length > 1) {
|
|
return;
|
|
}
|
|
|
|
var cons = switchCase.consequent[0];
|
|
|
|
// default case
|
|
if (!switchCase.test) {
|
|
if (!t.isReturnStatement(cons)) {
|
|
return;
|
|
}
|
|
defaultRet = cons;
|
|
continue;
|
|
}
|
|
|
|
if (!switchCase.consequent.length) {
|
|
fallThru.push(switchCase.test);
|
|
continue;
|
|
}
|
|
|
|
// TODO: can we void it?
|
|
if (!t.isReturnStatement(cons)) {
|
|
return;
|
|
}
|
|
|
|
var test = t.binaryExpression("===", node.discriminant, switchCase.test);
|
|
|
|
if (fallThru.length && !defaultRet) {
|
|
test = fallThru.reduceRight(function (right, test) {
|
|
return t.logicalExpression("||", t.binaryExpression("===", node.discriminant, test), right);
|
|
}, test);
|
|
}
|
|
fallThru = [];
|
|
|
|
consTestPairs.push([test, cons.argument || VOID_0]);
|
|
}
|
|
|
|
// Bail if we have any remaining fallthrough
|
|
} catch (err) {
|
|
_didIteratorError4 = true;
|
|
_iteratorError4 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion4 && _iterator4.return) {
|
|
_iterator4.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError4) {
|
|
throw _iteratorError4;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (fallThru.length) {
|
|
return;
|
|
}
|
|
|
|
// We need the default to be there to make sure there is an oppurtinity
|
|
// not to return.
|
|
if (!defaultRet) {
|
|
if (path.inList) {
|
|
var nextPath = path.getSibling(path.key + 1);
|
|
if (nextPath.isReturnStatement()) {
|
|
defaultRet = nextPath.node;
|
|
nextPath.remove();
|
|
} else if (!nextPath.node && path.parentPath.parentPath.isFunction()) {
|
|
// If this is the last statement in a function we just fake a void return.
|
|
defaultRet = t.returnStatement(VOID_0);
|
|
} else {
|
|
return;
|
|
}
|
|
} else {
|
|
return;
|
|
}
|
|
}
|
|
|
|
var cond = consTestPairs.reduceRight(function (alt, _ref3) {
|
|
var _ref4 = _slicedToArray(_ref3, 2),
|
|
test = _ref4[0],
|
|
cons = _ref4[1];
|
|
|
|
return t.conditionalExpression(test, cons, alt);
|
|
}, defaultRet.argument || VOID_0);
|
|
|
|
path.replaceWith(t.returnStatement(cond));
|
|
|
|
// Maybe now we can merge with some previous switch statement.
|
|
if (path.inList) {
|
|
var prev = path.getSibling(path.key - 1);
|
|
if (prev.isSwitchStatement()) {
|
|
prev.visit();
|
|
}
|
|
}
|
|
},
|
|
|
|
// Convert switches into conditionals.
|
|
function (path) {
|
|
var node = path.node;
|
|
|
|
// Need to be careful of side-effects.
|
|
|
|
if (!t.isIdentifier(node.discriminant)) {
|
|
return;
|
|
}
|
|
|
|
if (!node.cases.length) {
|
|
return;
|
|
}
|
|
|
|
var exprTestPairs = [];
|
|
var fallThru = [];
|
|
var defaultExpr = void 0;
|
|
var _iteratorNormalCompletion5 = true;
|
|
var _didIteratorError5 = false;
|
|
var _iteratorError5 = undefined;
|
|
|
|
try {
|
|
for (var _iterator5 = node.cases[Symbol.iterator](), _step5; !(_iteratorNormalCompletion5 = (_step5 = _iterator5.next()).done); _iteratorNormalCompletion5 = true) {
|
|
var switchCase = _step5.value;
|
|
|
|
if (!switchCase.test) {
|
|
if (switchCase.consequent.length !== 1) {
|
|
return;
|
|
}
|
|
if (!t.isExpressionStatement(switchCase.consequent[0])) {
|
|
return;
|
|
}
|
|
defaultExpr = switchCase.consequent[0].expression;
|
|
continue;
|
|
}
|
|
|
|
if (!switchCase.consequent.length) {
|
|
fallThru.push(switchCase.test);
|
|
continue;
|
|
}
|
|
|
|
var _switchCase$consequen = _slicedToArray(switchCase.consequent, 2),
|
|
cons = _switchCase$consequen[0],
|
|
breakStatement = _switchCase$consequen[1];
|
|
|
|
if (switchCase === node.cases[node.cases.length - 1]) {
|
|
if (breakStatement && !t.isBreakStatement(breakStatement)) {
|
|
return;
|
|
}
|
|
} else if (!t.isBreakStatement(breakStatement)) {
|
|
return;
|
|
}
|
|
|
|
if (!t.isExpressionStatement(cons) || switchCase.consequent.length > 2) {
|
|
return;
|
|
}
|
|
|
|
var test = t.binaryExpression("===", node.discriminant, switchCase.test);
|
|
if (fallThru.length && !defaultExpr) {
|
|
test = fallThru.reduceRight(function (right, test) {
|
|
return t.logicalExpression("||", t.binaryExpression("===", node.discriminant, test), right);
|
|
}, test);
|
|
}
|
|
fallThru = [];
|
|
|
|
exprTestPairs.push([test, cons.expression]);
|
|
}
|
|
} catch (err) {
|
|
_didIteratorError5 = true;
|
|
_iteratorError5 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion5 && _iterator5.return) {
|
|
_iterator5.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError5) {
|
|
throw _iteratorError5;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (fallThru.length) {
|
|
return;
|
|
}
|
|
|
|
var cond = exprTestPairs.reduceRight(function (alt, _ref5) {
|
|
var _ref6 = _slicedToArray(_ref5, 2),
|
|
test = _ref6[0],
|
|
cons = _ref6[1];
|
|
|
|
return t.conditionalExpression(test, cons, alt);
|
|
}, defaultExpr || VOID_0);
|
|
|
|
path.replaceWith(cond);
|
|
}, function (path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (!node.cases.length) {
|
|
return;
|
|
}
|
|
|
|
var lastCase = path.get("cases")[node.cases.length - 1];
|
|
if (!lastCase.node.consequent.length) {
|
|
return;
|
|
}
|
|
|
|
var potentialBreak = lastCase.get("consequent")[lastCase.node.consequent.length - 1];
|
|
if (t.isBreakStatement(potentialBreak) && potentialBreak.node.label === null) {
|
|
potentialBreak.remove();
|
|
}
|
|
}, createPrevExpressionEater("switch")]
|
|
}
|
|
}
|
|
};
|
|
|
|
function flipNegation(node) {
|
|
if (!node.consequent || !node.alternate) {
|
|
return;
|
|
}
|
|
|
|
var test = node.test;
|
|
var flip = false;
|
|
|
|
if (t.isBinaryExpression(test)) {
|
|
if (test.operator === "!==") {
|
|
test.operator = "===";
|
|
flip = true;
|
|
}
|
|
|
|
if (test.operator === "!=") {
|
|
test.operator = "==";
|
|
flip = true;
|
|
}
|
|
}
|
|
|
|
if (t.isUnaryExpression(test, { operator: "!" })) {
|
|
node.test = test.argument;
|
|
flip = true;
|
|
}
|
|
|
|
if (flip) {
|
|
var consequent = node.consequent;
|
|
node.consequent = node.alternate;
|
|
node.alternate = consequent;
|
|
}
|
|
}
|
|
|
|
function needsBlock(node, parent) {
|
|
return t.isFunction(parent) && node === parent.body || t.isTryStatement(parent) || t.isCatchClause(parent) || t.isSwitchStatement(parent) || isSingleBlockScopeDeclaration(node) && (t.isIfStatement(parent) || t.isLoop(parent));
|
|
}
|
|
|
|
function isSingleBlockScopeDeclaration(block) {
|
|
return t.isBlockStatement(block) && block.body.length === 1 && (t.isVariableDeclaration(block.body[0], { kind: "let" }) || t.isVariableDeclaration(block.body[0], { kind: "const" }) || t.isFunctionDeclaration(block.body[0]));
|
|
}
|
|
|
|
function isVoid0(expr) {
|
|
return expr === VOID_0 || t.isUnaryExpression(expr, { operator: "void" }) && t.isNumericLiteral(expr.argument, { value: 0 });
|
|
}
|
|
|
|
function earlyReturnTransform(path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (!t.isBlockStatement(node.body)) {
|
|
return;
|
|
}
|
|
|
|
for (var i = node.body.body.length; i >= 0; i--) {
|
|
var statement = node.body.body[i];
|
|
if (t.isIfStatement(statement) && !statement.alternate && t.isReturnStatement(statement.consequent) && !statement.consequent.argument) {
|
|
genericEarlyExitTransform(path.get("body").get("body")[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
function earlyContinueTransform(path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (!t.isBlockStatement(node.body)) {
|
|
return;
|
|
}
|
|
|
|
for (var i = node.body.body.length; i >= 0; i--) {
|
|
var statement = node.body.body[i];
|
|
if (t.isIfStatement(statement) && !statement.alternate && t.isContinueStatement(statement.consequent) && !statement.consequent.label) {
|
|
genericEarlyExitTransform(path.get("body").get("body")[i]);
|
|
}
|
|
}
|
|
|
|
// We may have reduced the body to a single statement.
|
|
if (node.body.body.length === 1 && !needsBlock(node.body, node)) {
|
|
path.get("body").replaceWith(node.body.body[0]);
|
|
}
|
|
}
|
|
|
|
function genericEarlyExitTransform(path) {
|
|
var node = path.node;
|
|
|
|
|
|
var statements = path.parentPath.get(path.listKey).slice(path.key + 1).filter(function (stmt) {
|
|
return !stmt.isFunctionDeclaration();
|
|
});
|
|
|
|
// deopt for any block scoped bindings
|
|
// issue#399
|
|
var deopt = !statements.every(function (stmt) {
|
|
if (!(stmt.isVariableDeclaration({ kind: "let" }) || stmt.isVariableDeclaration({ kind: "const" }))) {
|
|
return true;
|
|
}
|
|
var ids = Object.keys(stmt.getBindingIdentifiers());
|
|
var _iteratorNormalCompletion6 = true;
|
|
var _didIteratorError6 = false;
|
|
var _iteratorError6 = undefined;
|
|
|
|
try {
|
|
for (var _iterator6 = ids[Symbol.iterator](), _step6; !(_iteratorNormalCompletion6 = (_step6 = _iterator6.next()).done); _iteratorNormalCompletion6 = true) {
|
|
var id = _step6.value;
|
|
|
|
var binding = path.scope.getBinding(id);
|
|
|
|
// TODO
|
|
// Temporary Fix
|
|
// if there is no binding, we assume it is referenced outside
|
|
// and deopt to avoid bugs
|
|
if (!binding) {
|
|
return false;
|
|
}
|
|
|
|
var refs = [].concat(_toConsumableArray(binding.referencePaths), _toConsumableArray(binding.constantViolations));
|
|
var _iteratorNormalCompletion7 = true;
|
|
var _didIteratorError7 = false;
|
|
var _iteratorError7 = undefined;
|
|
|
|
try {
|
|
for (var _iterator7 = refs[Symbol.iterator](), _step7; !(_iteratorNormalCompletion7 = (_step7 = _iterator7.next()).done); _iteratorNormalCompletion7 = true) {
|
|
var ref = _step7.value;
|
|
|
|
if (!ref.isIdentifier()) return false;
|
|
var fnParent = ref.getFunctionParent();
|
|
|
|
// TODO
|
|
// Usage of scopes and bindings in simplify plugin results in
|
|
// undefined bindings because scope changes are not updated in the
|
|
// scope tree. So, we deopt whenever we encounter one such issue
|
|
// and not perform the transformation
|
|
if (!fnParent) {
|
|
return false;
|
|
}
|
|
if (fnParent.scope !== path.scope) return false;
|
|
}
|
|
} catch (err) {
|
|
_didIteratorError7 = true;
|
|
_iteratorError7 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion7 && _iterator7.return) {
|
|
_iterator7.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError7) {
|
|
throw _iteratorError7;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} catch (err) {
|
|
_didIteratorError6 = true;
|
|
_iteratorError6 = err;
|
|
} finally {
|
|
try {
|
|
if (!_iteratorNormalCompletion6 && _iterator6.return) {
|
|
_iterator6.return();
|
|
}
|
|
} finally {
|
|
if (_didIteratorError6) {
|
|
throw _iteratorError6;
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
});
|
|
|
|
if (deopt) {
|
|
path.visit();
|
|
return false;
|
|
}
|
|
|
|
if (!statements.length) {
|
|
path.replaceWith(t.expressionStatement(node.test));
|
|
return;
|
|
}
|
|
|
|
var test = node.test;
|
|
if (t.isBinaryExpression(test) && test.operator === "!==") {
|
|
test.operator = "===";
|
|
} else if (t.isBinaryExpression(test) && test.operator === "!=") {
|
|
test.operator = "==";
|
|
} else if (t.isUnaryExpression(test, { operator: "!" })) {
|
|
node.test = test.argument;
|
|
} else {
|
|
node.test = t.unaryExpression("!", node.test, true);
|
|
}
|
|
|
|
path.get("consequent").replaceWith(t.blockStatement(statements.map(function (stmt) {
|
|
return t.clone(stmt.node);
|
|
})));
|
|
|
|
var l = statements.length;
|
|
while (l-- > 0) {
|
|
if (!statements[l].isFunctionDeclaration()) {
|
|
path.getSibling(path.key + 1).remove();
|
|
}
|
|
}
|
|
|
|
// this should take care of removing the block
|
|
path.visit();
|
|
}
|
|
|
|
function createPrevExpressionEater(keyword) {
|
|
var key = void 0;
|
|
switch (keyword) {
|
|
case "switch":
|
|
key = "discriminant";
|
|
break;
|
|
case "throw":
|
|
case "return":
|
|
key = "argument";
|
|
break;
|
|
case "if":
|
|
key = "test";
|
|
break;
|
|
case "for-in":
|
|
key = "right";
|
|
break;
|
|
}
|
|
|
|
return function (path) {
|
|
if (!path.inList) {
|
|
return;
|
|
}
|
|
|
|
var node = path.node;
|
|
|
|
var prev = path.getSibling(path.key - 1);
|
|
if (!prev.isExpressionStatement()) {
|
|
return;
|
|
}
|
|
|
|
var seq = prev.node.expression;
|
|
if (node[key]) {
|
|
if (t.isSequenceExpression(seq)) {
|
|
seq.expressions.push(node[key]);
|
|
} else {
|
|
seq = t.sequenceExpression([seq, node[key]]);
|
|
}
|
|
} else {
|
|
if (t.isSequenceExpression(seq)) {
|
|
var lastExpr = seq.expressions[seq.expressions.length - 1];
|
|
seq.expressions[seq.expressions.length - 1] = t.unaryExpression("void", lastExpr, true);
|
|
} else {
|
|
seq = t.unaryExpression("void", seq, true);
|
|
}
|
|
}
|
|
|
|
if (seq) {
|
|
node[key] = seq;
|
|
prev.remove();
|
|
|
|
// Since we were able to merge some stuff it's possible that this has opened
|
|
// oppurtinties for other transforms to happen.
|
|
// TODO: Look into changing the traversal order from bottom to up to avoid
|
|
// having to revisit things.
|
|
if (path.parentPath.parent) {
|
|
path.parentPath.parent[shouldRevisit] = true;
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
// path1 -> path2
|
|
// is path1 an ancestor of path2
|
|
function isAncestor(path1, path2) {
|
|
return !!path2.findParent(function (parent) {
|
|
return parent === path1;
|
|
});
|
|
}
|
|
}; |