2016-07-14 22:58:48 -07:00

560 lines
14 KiB
JavaScript

/* eslint max-len: 0 */
import repeat from "lodash/repeat";
import Buffer from "./buffer";
import * as n from "./node";
import * as t from "babel-types";
export default class Printer {
constructor(format, map) {
this.format = format || {};
this._buf = new Buffer(map);
this.insideAux = false;
this._printAuxAfterOnNextUserNode = false;
this._printStack = [];
this._printedCommentStarts = {};
this._parenPushNewlineState = null;
this._indent = 0;
this.inForStatementInitCounter = 0;
}
_printedCommentStarts: Object;
_parenPushNewlineState: ?Object;
/**
* Increment indent size.
*/
indent(): void {
if (this.format.compact || this.format.concise) return;
this._indent++;
}
/**
* Decrement indent size.
*/
dedent(): void {
if (this.format.compact || this.format.concise) return;
this._indent--;
}
/**
* Add a semicolon to the buffer.
*/
semicolon(force: boolean = false): void {
this._append(";", !force /* queue */);
}
/**
* Add a right brace to the buffer.
*/
rightBrace(): void {
if (!this.endsWith("\n")) this.newline();
if (this.format.minified) {
this._buf.removeLastSemicolon();
}
this.token("}");
}
/**
* Add a keyword to the buffer.
*/
keyword(name: string): void {
this.word(name);
this.space();
}
/**
* Add a space to the buffer unless it is compact.
*/
space(force: boolean = false): void {
if (this.format.compact) return;
if ((this._buf.hasContent() && !this.endsWith(" ") && !this.endsWith("\n")) || force) {
this._space();
}
}
/**
* Writes a token that can't be safely parsed without taking whitespace into account.
*/
word(str: string): void {
if (this._endsWithWord) this._space();
this._append(str);
this._endsWithWord = true;
}
/**
* Writes a simple token.
*/
token(str: string): void {
const last = this._buf.getLast();
// space is mandatory to avoid outputting <!--
// http://javascript.spec.whatwg.org/#comment-syntax
if ((str === "--" && last === "!") ||
// Need spaces for operators of the same kind to avoid: `a+++b`
(str[0] === "+" && last === "+") ||
(str[0] === "-" && last === "-")) {
this._space();
}
this._append(str);
}
/**
* Add a newline (or many newlines), maintaining formatting.
*/
newline(i?: number): void {
if (this.format.retainLines || this.format.compact) return;
if (this.format.concise) {
this.space();
return;
}
// never allow more than two lines
if (this.endsWith("\n\n")) return;
if (typeof i !== "number") i = 1;
i = Math.min(2, i);
if (this.endsWith("{\n") || this.endsWith(":\n")) i--;
if (i <= 0) return;
this._buf.removeTrailingSpaces();
for (let j = 0; j < i; j++) {
this._newline();
}
}
endsWith(str: string): boolean {
return this._buf.endsWith(str);
}
removeTrailingNewline(): void {
this._buf.removeTrailingNewline();
}
source(prop: string, loc: Object): void {
this._catchUp(prop, loc);
this._buf.source(prop, loc);
}
withSource(prop: string, loc: Object, cb: () => void): void {
this._catchUp(prop, loc);
this._buf.withSource(prop, loc, cb);
}
_space(): void {
this._append(" ", true /* queue */);
}
_newline(): void {
this._append("\n", true /* queue */);
}
_append(str: string, queue: boolean = false) {
this._maybeAddParen(str);
this._maybeIndent(str);
if (queue) this._buf.queue(str);
else this._buf.append(str);
this._endsWithWord = false;
}
_maybeIndent(str: string): void {
// we've got a newline before us so prepend on the indentation
if (this._indent && this.endsWith("\n") && str[0] !== "\n") {
this._buf.queue(this._getIndent());
}
}
_maybeAddParen(str: string): void {
// see startTerminatorless() instance method
let parenPushNewlineState = this._parenPushNewlineState;
if (!parenPushNewlineState) return;
this._parenPushNewlineState = null;
let i;
for (i = 0; i < str.length && str[i] === " "; i++) continue;
if (i === str.length) return;
const cha = str[i];
if (cha === "\n" || cha === "/") {
// we're going to break this terminator expression so we need to add a parentheses
this.token("(");
this.indent();
parenPushNewlineState.printed = true;
}
}
_catchUp(prop: string, loc: Object) {
if (!this.format.retainLines) return;
// catch up to this nodes newline if we're behind
const pos = loc ? loc[prop] : null;
if (pos && pos.line !== null) {
while (this._buf.getCurrentLine() < pos.line) {
this._newline();
}
}
}
/**
* Get the current indent.
*/
_getIndent(): string {
return repeat(this.format.indent.style, this._indent);
}
/**
* Set some state that will be modified if a newline has been inserted before any
* non-space characters.
*
* This is to prevent breaking semantics for terminatorless separator nodes. eg:
*
* return foo;
*
* returns `foo`. But if we do:
*
* return
* foo;
*
* `undefined` will be returned and not `foo` due to the terminator.
*/
startTerminatorless(): Object {
return this._parenPushNewlineState = {
printed: false
};
}
/**
* Print an ending parentheses if a starting one has been printed.
*/
endTerminatorless(state: Object) {
if (state.printed) {
this.dedent();
this.newline();
this.token(")");
}
}
print(node, parent, opts = {}) {
if (!node) return;
let oldConcise = this.format.concise;
if (node._compact) {
this.format.concise = true;
}
let printMethod = this[node.type];
if (!printMethod) {
throw new ReferenceError(`unknown node of type ${JSON.stringify(node.type)} with constructor ${JSON.stringify(node && node.constructor.name)}`);
}
this._printStack.push(node);
let oldInAux = this.insideAux;
this.insideAux = !node.loc;
if (!this.insideAux) this.printAuxAfterComment();
else if (!oldInAux) this._printAuxBeforeComment();
let needsParens = n.needsParens(node, parent, this._printStack);
if (needsParens) this.token("(");
this._printLeadingComments(node, parent);
this._printNewline(true, node, parent, opts);
let loc = (t.isProgram(node) || t.isFile(node)) ? null : node.loc;
this.withSource("start", loc, () => {
this[node.type](node, parent);
});
// Check again if any of our children may have left an aux comment on the stack
if (!this.insideAux) this.printAuxAfterComment();
this._printTrailingComments(node, parent);
if (needsParens) this.token(")");
// end
this._printStack.pop();
if (opts.after) opts.after();
this.format.concise = oldConcise;
this.insideAux = oldInAux;
this._printNewline(false, node, parent, opts);
}
_printAuxBeforeComment() {
if (this._printAuxAfterOnNextUserNode) return;
this._printAuxAfterOnNextUserNode = true;
const comment = this.format.auxiliaryCommentBefore;
if (comment) {
this._printComment({
type: "CommentBlock",
value: comment
});
}
}
printAuxAfterComment() {
if (!this._printAuxAfterOnNextUserNode) return;
this._printAuxAfterOnNextUserNode = false;
const comment = this.format.auxiliaryCommentAfter;
if (comment) {
this._printComment({
type: "CommentBlock",
value: comment
});
}
}
getPossibleRaw(node) {
if (this.format.minified) return;
let extra = node.extra;
if (extra && extra.raw != null && extra.rawValue != null && node.value === extra.rawValue) {
return extra.raw;
}
}
printJoin(nodes: ?Array, parent: Object, opts = {}) {
if (!nodes || !nodes.length) return;
let len = nodes.length;
let node, i;
if (opts.indent) this.indent();
let printOpts = {
statement: opts.statement,
addNewlines: opts.addNewlines,
after: () => {
if (opts.iterator) {
opts.iterator(node, i);
}
if (opts.separator && parent.loc) {
this.printAuxAfterComment();
}
if (opts.separator && i < len - 1) {
opts.separator.call(this);
}
}
};
for (i = 0; i < nodes.length; i++) {
node = nodes[i];
this.print(node, parent, printOpts);
}
if (opts.indent) this.dedent();
}
printAndIndentOnComments(node, parent) {
let indent = !!node.leadingComments;
if (indent) this.indent();
this.print(node, parent);
if (indent) this.dedent();
}
printBlock(parent) {
let node = parent.body;
if (!t.isEmptyStatement(node)) {
this.space();
}
this.print(node, parent);
}
_printTrailingComments(node, parent) {
this._printComments(this._getComments(false, node, parent));
}
_printLeadingComments(node, parent) {
this._printComments(this._getComments(true, node, parent));
}
printInnerComments(node, indent = true) {
if (!node.innerComments) return;
if (indent) this.indent();
this._printComments(node.innerComments);
if (indent) this.dedent();
}
printSequence(nodes, parent, opts = {}) {
opts.statement = true;
return this.printJoin(nodes, parent, opts);
}
printList(items, parent, opts = {}) {
if (opts.separator == null) {
opts.separator = commaSeparator;
}
return this.printJoin(items, parent, opts);
}
_printNewline(leading, node, parent, opts) {
// Fast path since 'this.newline' does nothing when not tracking lines.
if (this.format.retainLines || this.format.compact) return;
if (!opts.statement && !n.isUserWhitespacable(node, parent)) {
return;
}
// Fast path for concise since 'this.newline' just inserts a space when
// concise formatting is in use.
if (this.format.concise) {
this.space();
return;
}
let lines = 0;
if (node.start != null && !node._ignoreUserWhitespace && this._whitespace) {
// user node
if (leading) {
lines = this._whitespace.getNewlinesBefore(node);
} else {
lines = this._whitespace.getNewlinesAfter(node);
}
} else {
// generated node
if (!leading) lines++; // always include at least a single line after
if (opts.addNewlines) lines += opts.addNewlines(leading, node) || 0;
let needs = n.needsWhitespaceAfter;
if (leading) needs = n.needsWhitespaceBefore;
if (needs(node, parent)) lines++;
// generated nodes can't add starting file whitespace
if (!this._buf.hasContent()) lines = 0;
}
this.newline(lines);
}
_getComments(leading, node) {
// Note, we use a boolean flag here instead of passing in the attribute name as it is faster
// because this is called extremely frequently.
return (node && (leading ? node.leadingComments : node.trailingComments)) || [];
}
_shouldPrintComment(comment) {
if (this.format.shouldPrintComment) {
return this.format.shouldPrintComment(comment.value);
} else {
if (!this.format.minified &&
(comment.value.indexOf("@license") >= 0 || comment.value.indexOf("@preserve") >= 0)) {
return true;
} else {
return this.format.comments;
}
}
}
_printComment(comment) {
if (!this._shouldPrintComment(comment)) return;
if (comment.ignore) return;
comment.ignore = true;
if (comment.start != null) {
if (this._printedCommentStarts[comment.start]) return;
this._printedCommentStarts[comment.start] = true;
}
// Exclude comments from source mappings since they will only clutter things.
this.withSource("start", comment.loc, () => {
// whitespace before
this.newline(this._whitespace ? this._whitespace.getNewlinesBefore(comment) : 0);
if (!this.endsWith("[") && !this.endsWith("{")) this.space();
let val = comment.type === "CommentLine" ? `//${comment.value}` : `/*${comment.value}*/`;
//
if (comment.type === "CommentBlock" && this.format.indent.adjustMultilineComment) {
let offset = comment.loc && comment.loc.start.column;
if (offset) {
let newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
val = val.replace(newlineRegex, "\n");
}
let indentSize = Math.max(this._getIndent().length, this._buf.getCurrentColumn());
val = val.replace(/\n(?!$)/g, `\n${repeat(" ", indentSize)}`);
}
// force a newline for line comments when retainLines is set in case the next printed node
// doesn't catch up
if ((this.format.compact || this.format.concise || this.format.retainLines) &&
comment.type === "CommentLine") {
val += "\n";
}
//
this.token(val);
// whitespace after
this.newline((this._whitespace ? this._whitespace.getNewlinesAfter(comment) : 0) ||
(comment.type === "CommentLine" ? 1 : 0));
});
}
_printComments(comments?: Array<Object>) {
if (!comments || !comments.length) return;
for (let comment of comments) {
this._printComment(comment);
}
}
}
function commaSeparator() {
this.token(",");
this.space();
}
for (let generator of [
require("./generators/template-literals"),
require("./generators/expressions"),
require("./generators/statements"),
require("./generators/classes"),
require("./generators/methods"),
require("./generators/modules"),
require("./generators/types"),
require("./generators/flow"),
require("./generators/base"),
require("./generators/jsx")
]) {
Object.assign(Printer.prototype, generator);
}