Dactyloidae/tools/lint/eslint/eslint-plugin-mozilla/lib/helpers.js

524 lines
14 KiB
JavaScript

/**
* @fileoverview A collection of helper 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";
var escope = require("escope");
var espree = require("espree");
var estraverse = require("estraverse");
var path = require("path");
var fs = require("fs");
var ini = require("ini-parser");
var modules = null;
var directoryManifests = new Map();
var definitions = [
/^loader\.lazyGetter\(this, "(\w+)"/,
/^loader\.lazyImporter\(this, "(\w+)"/,
/^loader\.lazyServiceGetter\(this, "(\w+)"/,
/^loader\.lazyRequireGetter\(this, "(\w+)"/,
/^XPCOMUtils\.defineLazyGetter\(this, "(\w+)"/,
/^XPCOMUtils\.defineLazyModuleGetter\(this, "(\w+)"/,
/^XPCOMUtils\.defineLazyServiceGetter\(this, "(\w+)"/,
/^XPCOMUtils\.defineConstant\(this, "(\w+)"/,
/^DevToolsUtils\.defineLazyModuleGetter\(this, "(\w+)"/,
/^DevToolsUtils\.defineLazyGetter\(this, "(\w+)"/,
/^Object\.defineProperty\(this, "(\w+)"/,
/^Reflect\.defineProperty\(this, "(\w+)"/,
/^this\.__defineGetter__\("(\w+)"/,
/^this\.(\w+) =/
];
var imports = [
/^(?:Cu|Components\.utils)\.import\(".*\/((.*?)\.jsm?)"(?:, this)?\)/,
];
module.exports = {
/**
* Gets the abstract syntax tree (AST) of the JavaScript source code contained
* in sourceText.
*
* @param {String} sourceText
* Text containing valid JavaScript.
*
* @return {Object}
* The resulting AST.
*/
getAST: function(sourceText) {
// Use a permissive config file to allow parsing of anything that Espree
// can parse.
var config = this.getPermissiveConfig();
return espree.parse(sourceText, config);
},
/**
* A simplistic conversion of some AST nodes to a standard string form.
*
* @param {Object} node
* The AST node to convert.
*
* @return {String}
* The JS source for the node.
*/
getASTSource: function(node) {
switch (node.type) {
case "MemberExpression":
if (node.computed)
throw new Error("getASTSource unsupported computed MemberExpression");
return this.getASTSource(node.object) + "." + this.getASTSource(node.property);
case "ThisExpression":
return "this";
case "Identifier":
return node.name;
case "Literal":
return JSON.stringify(node.value);
case "CallExpression":
var args = node.arguments.map(a => this.getASTSource(a)).join(", ");
return this.getASTSource(node.callee) + "(" + args + ")";
case "ObjectExpression":
return "{}";
case "ExpressionStatement":
return this.getASTSource(node.expression) + ";";
case "FunctionExpression":
return "function() {}";
case "ArrowFunctionExpression":
return "() => {}";
case "AssignmentExpression":
return this.getASTSource(node.left) + " = " + this.getASTSource(node.right);
default:
throw new Error("getASTSource unsupported node type: " + node.type);
}
},
/**
* This walks an AST in a manner similar to ESLint passing node and comment
* events to the listener. The listener is expected to be a simple function
* which accepts node type, node and parents arguments.
*
* @param {Object} ast
* The AST to walk.
* @param {Function} listener
* A callback function to call for the nodes. Passed three arguments,
* event type, node and an array of parent nodes for the current node.
*/
walkAST(ast, listener) {
let parents = [];
let seenComments = new Set();
function sendCommentEvents(comments) {
if (!comments) {
return;
}
for (let comment of comments) {
if (seenComments.has(comment)) {
return;
}
seenComments.add(comment);
listener(comment.type + "Comment", comment, parents);
}
}
estraverse.traverse(ast, {
enter(node, parent) {
// Comments are held in node.comments for empty programs
let leadingComments = node.leadingComments;
if (node.type === "Program" && node.body.length == 0) {
leadingComments = node.comments;
}
sendCommentEvents(leadingComments);
listener(node.type, node, parents);
sendCommentEvents(node.trailingComments);
parents.push(node);
},
leave(node, parent) {
// TODO send comment exit events
listener(node.type + ":exit", node, parents);
if (parents.length == 0) {
throw new Error("Left more nodes than entered.");
}
parents.pop();
}
});
if (parents.length) {
throw new Error("Entered more nodes than left.");
}
},
/**
* Attempts to convert an ExpressionStatement to likely global variable
* definitions.
*
* @param {Object} node
* The AST node to convert.
* @param {boolean} isGlobal
* True if the current node is in the global scope.
* @param {String} repository
* The root of the repository.
*
* @return {Array}
* An array of variable names defined.
*/
convertExpressionToGlobals: function(node, isGlobal, repository) {
if (!modules) {
modules = require(path.join(repository, "tools", "lint", "eslint", "modules.json"));
}
try {
var source = this.getASTSource(node);
}
catch (e) {
return [];
}
for (var reg of definitions) {
var match = source.match(reg);
if (match) {
// Must be in the global scope
if (!isGlobal) {
return [];
}
return [match[1]];
}
}
for (reg of imports) {
var match = source.match(reg);
if (match) {
// The two argument form is only acceptable in the global scope
if (node.expression.arguments.length > 1 && !isGlobal) {
return [];
}
if (match[1] in modules) {
return modules[match[1]];
}
return [match[2]];
}
}
return [];
},
/**
* Add a variable to the current scope.
* HACK: This relies on eslint internals so it could break at any time.
*
* @param {String} name
* The variable name to add to the scope.
* @param {ASTScope} scope
* The scope to add to.
* @param {boolean} writable
* Whether the global can be overwritten.
*/
addVarToScope: function(name, scope, writable) {
scope.__defineGeneric(name, scope.set, scope.variables, null, null);
let variable = scope.set.get(name);
variable.eslintExplicitGlobal = false;
variable.writeable = writable;
// Walk to the global scope which holds all undeclared variables.
while (scope.type != "global") {
scope = scope.upper;
}
// "through" contains all references with no found definition.
scope.through = scope.through.filter(function(reference) {
if (reference.identifier.name != name) {
return true;
}
// Links the variable and the reference.
// And this reference is removed from `Scope#through`.
reference.resolved = variable;
variable.references.push(reference);
return false;
});
},
/**
* Adds a set of globals to a scope.
*
* @param {Array} globalVars
* An array of global variable names.
* @param {ASTScope} scope
* The scope.
*/
addGlobals: function(globalVars, scope) {
globalVars.forEach(v => this.addVarToScope(v.name, scope, v.writable));
},
/**
* To allow espree to parse almost any JavaScript we need as many features as
* possible turned on. This method returns that config.
*
* @return {Object}
* Espree compatible permissive config.
*/
getPermissiveConfig: function() {
return {
range: true,
loc: true,
comment: true,
attachComment: true,
ecmaVersion: 8,
sourceType: "script",
ecmaFeatures: {
experimentalObjectRestSpread: true,
globalReturn: true,
}
};
},
/**
* Check whether the context is the global scope.
*
* @param {Array} ancestors
* The parents of the current node.
*
* @return {Boolean}
* True or false
*/
getIsGlobalScope: function(ancestors) {
for (let parent of ancestors) {
if (parent.type == "FunctionExpression" ||
parent.type == "FunctionDeclaration") {
return false;
}
}
return true;
},
/**
* Check whether we might be in a test head file.
*
* @param {RuleContext} scope
* You should pass this from within a rule
* e.g. helpers.getIsHeadFile(this)
*
* @return {Boolean}
* True or false
*/
getIsHeadFile: function(scope) {
var pathAndFilename = this.cleanUpPath(scope.getFilename());
return /.*[\\/]head(_.+)?\.js$/.test(pathAndFilename);
},
/**
* Gets the head files for a potential test file
*
* @param {RuleContext} scope
* You should pass this from within a rule
* e.g. helpers.getIsHeadFile(this)
*
* @return {String[]}
* Paths to head files to load for the test
*/
getTestHeadFiles: function(scope) {
if (!this.getIsTest(scope)) {
return [];
}
let filepath = this.cleanUpPath(scope.getFilename());
let dir = path.dirname(filepath);
let names = fs.readdirSync(dir)
.filter(name => name.startsWith("head") && name.endsWith(".js"))
.map(name => path.join(dir, name));
return names;
},
/**
* Gets all the test manifest data for a directory
*
* @param {String} dir
* The directory
*
* @return {Array}
* An array of objects with file and manifest properties
*/
getManifestsForDirectory: function(dir) {
if (directoryManifests.has(dir)) {
return directoryManifests.get(dir);
}
let manifests = [];
let names = fs.readdirSync(dir);
for (let name of names) {
if (!name.endsWith(".ini")) {
continue;
}
try {
let manifest = ini.parse(fs.readFileSync(path.join(dir, name), 'utf8'));
manifests.push({
file: path.join(dir, name),
manifest
})
} catch (e) {
}
}
directoryManifests.set(dir, manifests);
return manifests;
},
/**
* Gets the manifest file a test is listed in
*
* @param {RuleContext} scope
* You should pass this from within a rule
* e.g. helpers.getIsHeadFile(this)
*
* @return {String}
* The path to the test manifest file
*/
getTestManifest: function(scope) {
let filepath = this.cleanUpPath(scope.getFilename());
let dir = path.dirname(filepath);
let filename = path.basename(filepath);
for (let manifest of this.getManifestsForDirectory(dir)) {
if (filename in manifest.manifest) {
return manifest.file;
}
}
return null;
},
/**
* Check whether we are in a test of some kind.
*
* @param {RuleContext} scope
* You should pass this from within a rule
* e.g. helpers.getIsTest(this)
*
* @return {Boolean}
* True or false
*/
getIsTest: function(scope) {
// Regardless of the manifest name being in a manifest means we're a test.
let manifest = this.getTestManifest(scope);
if (manifest) {
return true;
}
return !!this.getTestType(scope);
},
/**
* Gets the type of test or null if this isn't a test.
*
* @param {RuleContext} scope
* You should pass this from within a rule
* e.g. helpers.getIsHeadFile(this)
*
* @return {String or null}
* Test type: xpcshell, browser, chrome, mochitest
*/
getTestType: function(scope) {
let manifest = this.getTestManifest(scope);
if (manifest) {
let name = path.basename(manifest);
for (let testType of ["browser", "xpcshell", "chrome", "mochitest"]) {
if (name.startsWith(testType)) {
return testType;
}
}
}
let filepath = this.cleanUpPath(scope.getFilename());
let filename = path.basename(filepath);
if (filename.startsWith("browser_")) {
return "browser";
}
if (filename.startsWith("test_")) {
return "xpcshell";
}
return null;
},
/**
* Gets the root directory of the repository by walking up directories until
* a .eslintignore file is found.
* @param {String} fileName
* The absolute path of a file in the repository
*
* @return {String} The absolute path of the repository directory
*/
getRootDir: function(fileName) {
var dirName = path.dirname(fileName);
while (dirName && !fs.existsSync(path.join(dirName, ".eslintignore"))) {
dirName = path.dirname(dirName);
}
if (!dirName) {
throw new Error("Unable to find root of repository");
}
return dirName;
},
/**
* ESLint may be executed from various places: from mach, at the root of the
* repository, or from a directory in the repository when, for instance,
* executed by a text editor's plugin.
* The value returned by context.getFileName() varies because of this.
* This helper function makes sure to return an absolute file path for the
* current context, by looking at process.cwd().
* @param {Context} context
* @return {String} The absolute path
*/
getAbsoluteFilePath: function(context) {
var fileName = this.cleanUpPath(context.getFilename());
var cwd = process.cwd();
if (path.isAbsolute(fileName)) {
// Case 2: executed from the repo's root with mach:
// fileName: /path/to/mozilla/repo/a/b/c/d.js
// cwd: /path/to/mozilla/repo
return fileName;
} else if (path.basename(fileName) == fileName) {
// Case 1b: executed from a nested directory, fileName is the base name
// without any path info (happens in Atom with linter-eslint)
return path.join(cwd, fileName);
} else {
// Case 1: executed form in a nested directory, e.g. from a text editor:
// fileName: a/b/c/d.js
// cwd: /path/to/mozilla/repo/a/b/c
var dirName = path.dirname(fileName);
return cwd.slice(0, cwd.length - dirName.length) + fileName;
}
},
/**
* When ESLint is run from SublimeText, paths retrieved from
* context.getFileName contain leading and trailing double-quote characters.
* These characters need to be removed.
*/
cleanUpPath: function(path) {
return path.replace(/^"/, "").replace(/"$/, "");
}
};