Dactyloidae/tools/lint/eslint/eslint-plugin-mozilla/lib/processors/xbl-bindings.js

363 lines
11 KiB
JavaScript

/**
* @fileoverview Converts functions and handlers from XBL bindings into JS
* functions
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
"use strict";
const NS_XBL = "http://www.mozilla.org/xbl";
let sax = require("sax");
// Converts sax's error message to something that eslint will understand
let errorRegex = /(.*)\nLine: (\d+)\nColumn: (\d+)\nChar: (.*)/
function parseError(err) {
let matches = err.message.match(errorRegex);
if (!matches)
return null;
return {
fatal: true,
message: matches[1],
line: parseInt(matches[2]) + 1,
column: parseInt(matches[3])
}
}
let entityRegex = /&[\w][\w-\.]*;/g;
// A simple sax listener that generates a tree of element information
function XMLParser(parser) {
this.parser = parser;
parser.onopentag = this.onOpenTag.bind(this);
parser.onclosetag = this.onCloseTag.bind(this);
parser.ontext = this.onText.bind(this);
parser.onopencdata = this.onOpenCDATA.bind(this);
parser.oncdata = this.onCDATA.bind(this);
parser.oncomment = this.onComment.bind(this);
this.document = {
local: "#document",
uri: null,
children: [],
comments: [],
}
this._currentNode = this.document;
}
XMLParser.prototype = {
parser: null,
onOpenTag: function(tag) {
let node = {
parentNode: this._currentNode,
local: tag.local,
namespace: tag.uri,
attributes: {},
children: [],
comments: [],
textContent: "",
textLine: this.parser.line,
textColumn: this.parser.column,
textEndLine: this.parser.line
}
for (let attr of Object.keys(tag.attributes)) {
if (tag.attributes[attr].uri == "") {
node.attributes[attr] = tag.attributes[attr].value;
}
}
this._currentNode.children.push(node);
this._currentNode = node;
},
onCloseTag: function(tagname) {
this._currentNode.textEndLine = this.parser.line;
this._currentNode = this._currentNode.parentNode;
},
addText: function(text) {
this._currentNode.textContent += text;
},
onText: function(text) {
// Replace entities with some valid JS token.
this.addText(text.replace(entityRegex, "null"));
},
onOpenCDATA: function() {
// Turn the CDATA opening tag into whitespace for indent alignment
this.addText(" ".repeat("<![CDATA[".length));
},
onCDATA: function(text) {
this.addText(text);
},
onComment: function(text) {
this._currentNode.comments.push(text);
}
}
// -----------------------------------------------------------------------------
// Processor Definition
// -----------------------------------------------------------------------------
const INDENT_LEVEL = 2;
function indent(count) {
return " ".repeat(count * INDENT_LEVEL);
}
// Stores any XML parse error
let xmlParseError = null;
// Stores the lines of JS code generated from the XBL
let scriptLines = [];
// Stores a map from the synthetic line number to the real line number
// and column offset.
let lineMap = [];
function addSyntheticLine(line, linePos, addDisableLine) {
lineMap[scriptLines.length] = { line: linePos, offset: null };
scriptLines.push(line + (addDisableLine ? "" : " // eslint-disable-line"));
}
/**
* Adds generated lines from an XBL node to the script to be passed back to eslint.
*/
function addNodeLines(node, reindent) {
let lines = node.textContent.split("\n");
let startLine = node.textLine;
let startColumn = node.textColumn;
// The case where there are no whitespace lines before the first text is
// treated differently for indentation
let indentFirst = false;
// Strip off any preceeding whitespace only lines. These are often used to
// format the XML and CDATA blocks.
while (lines.length && lines[0].trim() == "") {
indentFirst = true;
startLine++;
lines.shift();
}
// Strip off any whitespace lines at the end. These are often used to line
// up the closing tags
while (lines.length && lines[lines.length - 1].trim() == "") {
lines.pop();
}
if (!indentFirst) {
let firstLine = lines.shift();
firstLine = " ".repeat(reindent * INDENT_LEVEL) + firstLine;
// ESLint counts columns starting at 1 rather than 0
lineMap[scriptLines.length] = { line: startLine, offset: reindent * INDENT_LEVEL - (startColumn - 1) };
scriptLines.push(firstLine);
startLine++;
}
// Find the preceeding whitespace for all lines that aren't entirely whitespace
let indents = lines.filter(s => s.trim().length > 0)
.map(s => s.length - s.trimLeft().length);
// Find the smallest indent level in use
let minIndent = Math.min.apply(null, indents);
for (let line of lines) {
if (line.trim().length == 0) {
// Don't offset lines that are only whitespace, the only possible JS error
// is trailing whitespace and we want it to point at the right place
lineMap[scriptLines.length] = { line: startLine, offset: 0 };
} else {
line = " ".repeat(reindent * INDENT_LEVEL) + line.substring(minIndent);
lineMap[scriptLines.length] = { line: startLine, offset: reindent * INDENT_LEVEL - (minIndent - 1) };
}
scriptLines.push(line);
startLine++;
}
}
module.exports = {
preprocess: function(text, filename) {
xmlParseError = null;
scriptLines = [];
lineMap = [];
// Non-strict allows us to ignore many errors from entities and
// preprocessing at the expense of failing to report some XML errors.
// Unfortunately it also throws away the case of tagnames and attributes
let parser = sax.parser(false, {
lowercase: true,
xmlns: true,
});
parser.onerror = function(err) {
xmlParseError = parseError(err);
}
let xp = new XMLParser(parser);
parser.write(text);
// Sanity checks to make sure we're dealing with an XBL document
let document = xp.document;
if (document.children.length != 1) {
return [];
}
let bindings = document.children[0];
if (bindings.local != "bindings" || bindings.namespace != NS_XBL) {
return [];
}
for (let comment of document.comments) {
addSyntheticLine(`/*`, 0, true);
for (let line of comment.split("\n")) {
addSyntheticLine(`${line.trim()}`, 0, true);
}
addSyntheticLine(`*/`, 0, true);
}
addSyntheticLine(`this.bindings = {`, bindings.textLine);
for (let binding of bindings.children) {
if (binding.local != "binding" || binding.namespace != NS_XBL) {
continue;
}
addSyntheticLine(indent(1) + `"${binding.attributes.id}": {`, binding.textLine);
for (let part of binding.children) {
if (part.namespace != NS_XBL) {
continue;
}
if (part.local == "implementation") {
addSyntheticLine(indent(2) + `implementation: {`, part.textLine);
} else if (part.local == "handlers") {
addSyntheticLine(indent(2) + `handlers: [`, part.textLine);
} else {
continue;
}
for (let item of part.children) {
if (item.namespace != NS_XBL) {
continue;
}
switch (item.local) {
case "field": {
// Fields are something like lazy getter functions
// Ignore empty fields
if (item.textContent.trim().length == 0) {
continue;
}
addSyntheticLine(indent(3) + `get ${item.attributes.name}() {`, item.textLine);
addSyntheticLine(indent(4) + `return (`, item.textLine);
// Remove trailing semicolons, as we are adding our own
item.textContent = item.textContent.replace(/;(?=\s*$)/, "");
addNodeLines(item, 5);
addSyntheticLine(indent(4) + `);`, item.textLine);
addSyntheticLine(indent(3) + `},`, item.textEndLine);
break;
}
case "constructor":
case "destructor": {
// Constructors and destructors become function declarations
addSyntheticLine(indent(3) + `${item.local}() {`, item.textLine);
addNodeLines(item, 4);
addSyntheticLine(indent(3) + `},`, item.textEndLine);
break;
}
case "method": {
// Methods become function declarations with the appropriate params
let params = item.children.filter(n => n.local == "parameter" && n.namespace == NS_XBL)
.map(n => n.attributes.name)
.join(", ");
let body = item.children.filter(n => n.local == "body" && n.namespace == NS_XBL)[0];
addSyntheticLine(indent(3) + `${item.attributes.name}(${params}) {`, item.textLine);
addNodeLines(body, 4);
addSyntheticLine(indent(3) + `},`, item.textEndLine);
break;
}
case "property": {
// Properties become one or two function declarations
for (let propdef of item.children) {
if (propdef.namespace != NS_XBL) {
continue;
}
if (propdef.local == "setter") {
addSyntheticLine(indent(3) + `set ${item.attributes.name}(val) {`, propdef.textLine);
} else if (propdef.local == "getter") {
addSyntheticLine(indent(3) + `get ${item.attributes.name}() {`, propdef.textLine);
} else {
continue;
}
addNodeLines(propdef, 4);
addSyntheticLine(indent(3) + `},`, propdef.textEndLine);
}
break;
}
case "handler": {
// Handlers become a function declaration with an `event` parameter
addSyntheticLine(indent(3) + `function(event) {`, item.textLine);
addNodeLines(item, 4);
addSyntheticLine(indent(3) + `},`, item.textEndLine);
break;
}
default:
continue;
}
}
addSyntheticLine(indent(2) + (part.local == "implementation" ? `},` : `],`), part.textEndLine);
}
addSyntheticLine(indent(1) + `},`, binding.textEndLine);
}
addSyntheticLine(`};`, bindings.textEndLine);
let script = scriptLines.join("\n") + "\n";
return [script];
},
postprocess: function(messages, filename) {
// If there was an XML parse error then just return that
if (xmlParseError) {
return [xmlParseError];
}
// For every message from every script block update the line to point to the
// correct place.
let errors = [];
for (let i = 0; i < messages.length; i++) {
for (let message of messages[i]) {
// ESLint indexes lines starting at 1 but our arrays start at 0
let mapped = lineMap[message.line - 1];
message.line = mapped.line + 1;
if (mapped.offset) {
message.column -= mapped.offset;
} else {
message.column = NaN;
}
errors.push(message);
}
}
return errors;
}
};