"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); exports.getReprinter = exports.Patcher = void 0; var tslib_1 = require("tslib"); var assert_1 = tslib_1.__importDefault(require("assert")); var linesModule = tslib_1.__importStar(require("./lines")); var types = tslib_1.__importStar(require("ast-types")); var Printable = types.namedTypes.Printable; var Expression = types.namedTypes.Expression; var ReturnStatement = types.namedTypes.ReturnStatement; var SourceLocation = types.namedTypes.SourceLocation; var util_1 = require("./util"); var fast_path_1 = tslib_1.__importDefault(require("./fast-path")); var isObject = types.builtInTypes.object; var isArray = types.builtInTypes.array; var isString = types.builtInTypes.string; var riskyAdjoiningCharExp = /[0-9a-z_$]/i; var Patcher = function Patcher(lines) { assert_1.default.ok(this instanceof Patcher); assert_1.default.ok(lines instanceof linesModule.Lines); var self = this, replacements = []; self.replace = function (loc, lines) { if (isString.check(lines)) lines = linesModule.fromString(lines); replacements.push({ lines: lines, start: loc.start, end: loc.end, }); }; self.get = function (loc) { // If no location is provided, return the complete Lines object. loc = loc || { start: { line: 1, column: 0 }, end: { line: lines.length, column: lines.getLineLength(lines.length) }, }; var sliceFrom = loc.start, toConcat = []; function pushSlice(from, to) { assert_1.default.ok(util_1.comparePos(from, to) <= 0); toConcat.push(lines.slice(from, to)); } replacements .sort(function (a, b) { return util_1.comparePos(a.start, b.start); }) .forEach(function (rep) { if (util_1.comparePos(sliceFrom, rep.start) > 0) { // Ignore nested replacement ranges. } else { pushSlice(sliceFrom, rep.start); toConcat.push(rep.lines); sliceFrom = rep.end; } }); pushSlice(sliceFrom, loc.end); return linesModule.concat(toConcat); }; }; exports.Patcher = Patcher; var Pp = Patcher.prototype; Pp.tryToReprintComments = function (newNode, oldNode, print) { var patcher = this; if (!newNode.comments && !oldNode.comments) { // We were (vacuously) able to reprint all the comments! return true; } var newPath = fast_path_1.default.from(newNode); var oldPath = fast_path_1.default.from(oldNode); newPath.stack.push("comments", getSurroundingComments(newNode)); oldPath.stack.push("comments", getSurroundingComments(oldNode)); var reprints = []; var ableToReprintComments = findArrayReprints(newPath, oldPath, reprints); // No need to pop anything from newPath.stack or oldPath.stack, since // newPath and oldPath are fresh local variables. if (ableToReprintComments && reprints.length > 0) { reprints.forEach(function (reprint) { var oldComment = reprint.oldPath.getValue(); assert_1.default.ok(oldComment.leading || oldComment.trailing); patcher.replace(oldComment.loc, // Comments can't have .comments, so it doesn't matter whether we // print with comments or without. print(reprint.newPath).indentTail(oldComment.loc.indent)); }); } return ableToReprintComments; }; // Get all comments that are either leading or trailing, ignoring any // comments that occur inside node.loc. Returns an empty array for nodes // with no leading or trailing comments. function getSurroundingComments(node) { var result = []; if (node.comments && node.comments.length > 0) { node.comments.forEach(function (comment) { if (comment.leading || comment.trailing) { result.push(comment); } }); } return result; } Pp.deleteComments = function (node) { if (!node.comments) { return; } var patcher = this; node.comments.forEach(function (comment) { if (comment.leading) { // Delete leading comments along with any trailing whitespace they // might have. patcher.replace({ start: comment.loc.start, end: node.loc.lines.skipSpaces(comment.loc.end, false, false), }, ""); } else if (comment.trailing) { // Delete trailing comments along with any leading whitespace they // might have. patcher.replace({ start: node.loc.lines.skipSpaces(comment.loc.start, true, false), end: comment.loc.end, }, ""); } }); }; function getReprinter(path) { assert_1.default.ok(path instanceof fast_path_1.default); // Make sure that this path refers specifically to a Node, rather than // some non-Node subproperty of a Node. var node = path.getValue(); if (!Printable.check(node)) return; var orig = node.original; var origLoc = orig && orig.loc; var lines = origLoc && origLoc.lines; var reprints = []; if (!lines || !findReprints(path, reprints)) return; return function (print) { var patcher = new Patcher(lines); reprints.forEach(function (reprint) { var newNode = reprint.newPath.getValue(); var oldNode = reprint.oldPath.getValue(); SourceLocation.assert(oldNode.loc, true); var needToPrintNewPathWithComments = !patcher.tryToReprintComments(newNode, oldNode, print); if (needToPrintNewPathWithComments) { // Since we were not able to preserve all leading/trailing // comments, we delete oldNode's comments, print newPath with // comments, and then patch the resulting lines where oldNode used // to be. patcher.deleteComments(oldNode); } var newLines = print(reprint.newPath, { includeComments: needToPrintNewPathWithComments, // If the oldNode we're replacing already had parentheses, we may // not need to print the new node with any extra parentheses, // because the existing parentheses will suffice. However, if the // newNode has a different type than the oldNode, let the printer // decide if reprint.newPath needs parentheses, as usual. avoidRootParens: oldNode.type === newNode.type && reprint.oldPath.hasParens(), }).indentTail(oldNode.loc.indent); var nls = needsLeadingSpace(lines, oldNode.loc, newLines); var nts = needsTrailingSpace(lines, oldNode.loc, newLines); // If we try to replace the argument of a ReturnStatement like // return"asdf" with e.g. a literal null expression, we run the risk // of ending up with returnnull, so we need to add an extra leading // space in situations where that might happen. Likewise for // "asdf"in obj. See #170. if (nls || nts) { var newParts = []; nls && newParts.push(" "); newParts.push(newLines); nts && newParts.push(" "); newLines = linesModule.concat(newParts); } patcher.replace(oldNode.loc, newLines); }); // Recall that origLoc is the .loc of an ancestor node that is // guaranteed to contain all the reprinted nodes and comments. var patchedLines = patcher.get(origLoc).indentTail(-orig.loc.indent); if (path.needsParens()) { return linesModule.concat(["(", patchedLines, ")"]); } return patchedLines; }; } exports.getReprinter = getReprinter; // If the last character before oldLoc and the first character of newLines // are both identifier characters, they must be separated by a space, // otherwise they will most likely get fused together into a single token. function needsLeadingSpace(oldLines, oldLoc, newLines) { var posBeforeOldLoc = util_1.copyPos(oldLoc.start); // The character just before the location occupied by oldNode. var charBeforeOldLoc = oldLines.prevPos(posBeforeOldLoc) && oldLines.charAt(posBeforeOldLoc); // First character of the reprinted node. var newFirstChar = newLines.charAt(newLines.firstPos()); return (charBeforeOldLoc && riskyAdjoiningCharExp.test(charBeforeOldLoc) && newFirstChar && riskyAdjoiningCharExp.test(newFirstChar)); } // If the last character of newLines and the first character after oldLoc // are both identifier characters, they must be separated by a space, // otherwise they will most likely get fused together into a single token. function needsTrailingSpace(oldLines, oldLoc, newLines) { // The character just after the location occupied by oldNode. var charAfterOldLoc = oldLines.charAt(oldLoc.end); var newLastPos = newLines.lastPos(); // Last character of the reprinted node. var newLastChar = newLines.prevPos(newLastPos) && newLines.charAt(newLastPos); return (newLastChar && riskyAdjoiningCharExp.test(newLastChar) && charAfterOldLoc && riskyAdjoiningCharExp.test(charAfterOldLoc)); } function findReprints(newPath, reprints) { var newNode = newPath.getValue(); Printable.assert(newNode); var oldNode = newNode.original; Printable.assert(oldNode); assert_1.default.deepEqual(reprints, []); if (newNode.type !== oldNode.type) { return false; } var oldPath = new fast_path_1.default(oldNode); var canReprint = findChildReprints(newPath, oldPath, reprints); if (!canReprint) { // Make absolutely sure the calling code does not attempt to reprint // any nodes. reprints.length = 0; } return canReprint; } function findAnyReprints(newPath, oldPath, reprints) { var newNode = newPath.getValue(); var oldNode = oldPath.getValue(); if (newNode === oldNode) return true; if (isArray.check(newNode)) return findArrayReprints(newPath, oldPath, reprints); if (isObject.check(newNode)) return findObjectReprints(newPath, oldPath, reprints); return false; } function findArrayReprints(newPath, oldPath, reprints) { var newNode = newPath.getValue(); var oldNode = oldPath.getValue(); if (newNode === oldNode || newPath.valueIsDuplicate() || oldPath.valueIsDuplicate()) { return true; } isArray.assert(newNode); var len = newNode.length; if (!(isArray.check(oldNode) && oldNode.length === len)) return false; for (var i = 0; i < len; ++i) { newPath.stack.push(i, newNode[i]); oldPath.stack.push(i, oldNode[i]); var canReprint = findAnyReprints(newPath, oldPath, reprints); newPath.stack.length -= 2; oldPath.stack.length -= 2; if (!canReprint) { return false; } } return true; } function findObjectReprints(newPath, oldPath, reprints) { var newNode = newPath.getValue(); isObject.assert(newNode); if (newNode.original === null) { // If newNode.original node was set to null, reprint the node. return false; } var oldNode = oldPath.getValue(); if (!isObject.check(oldNode)) return false; if (newNode === oldNode || newPath.valueIsDuplicate() || oldPath.valueIsDuplicate()) { return true; } if (Printable.check(newNode)) { if (!Printable.check(oldNode)) { return false; } var newParentNode = newPath.getParentNode(); var oldParentNode = oldPath.getParentNode(); if (oldParentNode !== null && oldParentNode.type === "FunctionTypeAnnotation" && newParentNode !== null && newParentNode.type === "FunctionTypeAnnotation") { var oldNeedsParens = oldParentNode.params.length !== 1 || !!oldParentNode.params[0].name; var newNeedParens = newParentNode.params.length !== 1 || !!newParentNode.params[0].name; if (!oldNeedsParens && newNeedParens) { return false; } } // Here we need to decide whether the reprinted code for newNode is // appropriate for patching into the location of oldNode. if (newNode.type === oldNode.type) { var childReprints = []; if (findChildReprints(newPath, oldPath, childReprints)) { reprints.push.apply(reprints, childReprints); } else if (oldNode.loc) { // If we have no .loc information for oldNode, then we won't be // able to reprint it. reprints.push({ oldPath: oldPath.copy(), newPath: newPath.copy(), }); } else { return false; } return true; } if (Expression.check(newNode) && Expression.check(oldNode) && // If we have no .loc information for oldNode, then we won't be // able to reprint it. oldNode.loc) { // If both nodes are subtypes of Expression, then we should be able // to fill the location occupied by the old node with code printed // for the new node with no ill consequences. reprints.push({ oldPath: oldPath.copy(), newPath: newPath.copy(), }); return true; } // The nodes have different types, and at least one of the types is // not a subtype of the Expression type, so we cannot safely assume // the nodes are syntactically interchangeable. return false; } return findChildReprints(newPath, oldPath, reprints); } function findChildReprints(newPath, oldPath, reprints) { var newNode = newPath.getValue(); var oldNode = oldPath.getValue(); isObject.assert(newNode); isObject.assert(oldNode); if (newNode.original === null) { // If newNode.original node was set to null, reprint the node. return false; } // If this node needs parentheses and will not be wrapped with // parentheses when reprinted, then return false to skip reprinting and // let it be printed generically. if (newPath.needsParens() && !oldPath.hasParens()) { return false; } var keys = util_1.getUnionOfKeys(oldNode, newNode); if (oldNode.type === "File" || newNode.type === "File") { // Don't bother traversing file.tokens, an often very large array // returned by Babylon, and useless for our purposes. delete keys.tokens; } // Don't bother traversing .loc objects looking for reprintable nodes. delete keys.loc; var originalReprintCount = reprints.length; for (var k in keys) { if (k.charAt(0) === "_") { // Ignore "private" AST properties added by e.g. Babel plugins and // parsers like Babylon. continue; } newPath.stack.push(k, types.getFieldValue(newNode, k)); oldPath.stack.push(k, types.getFieldValue(oldNode, k)); var canReprint = findAnyReprints(newPath, oldPath, reprints); newPath.stack.length -= 2; oldPath.stack.length -= 2; if (!canReprint) { return false; } } // Return statements might end up running into ASI issues due to // comments inserted deep within the tree, so reprint them if anything // changed within them. if (ReturnStatement.check(newPath.getNode()) && reprints.length > originalReprintCount) { return false; } return true; }