gecko-dev/testing/modules/FileTestUtils.jsm

153 lines
5.7 KiB
JavaScript

/* 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/. */
/**
* Provides testing functions dealing with local files and their contents.
*/
"use strict";
var EXPORTED_SYMBOLS = ["FileTestUtils"];
const { AsyncShutdown } = ChromeUtils.import(
"resource://gre/modules/AsyncShutdown.jsm"
);
const { DownloadPaths } = ChromeUtils.import(
"resource://gre/modules/DownloadPaths.jsm"
);
const { FileUtils } = ChromeUtils.import(
"resource://gre/modules/FileUtils.jsm"
);
const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
const { XPCOMUtils } = ChromeUtils.import(
"resource://gre/modules/XPCOMUtils.jsm"
);
const { Assert } = ChromeUtils.import("resource://testing-common/Assert.jsm");
let gFileCounter = 1;
let gPathsToRemove = [];
var FileTestUtils = {
/**
* Returns a reference to a temporary file that is guaranteed not to exist and
* to have never been created before. If a file or a directory with this name
* is created by the test, it will be deleted when all tests terminate.
*
* @param suggestedName [optional]
* Any extension on this template file name will be preserved. If this
* is unspecified, the returned file name will have the generic ".dat"
* extension, which may indicate either a binary or a text data file.
*
* @return nsIFile pointing to a non-existent file in a temporary directory.
*
* @note It is not enough to delete the file if it exists, or to delete the
* file after calling nsIFile.createUnique, because on Windows the
* delete operation in the file system may still be pending, preventing
* a new file with the same name to be created.
*/
getTempFile(suggestedName = "test.dat") {
// Prepend a serial number to the extension in the suggested leaf name.
let [base, ext] = DownloadPaths.splitBaseNameAndExtension(suggestedName);
let leafName = base + "-" + gFileCounter + ext;
gFileCounter++;
// Get a file reference under the temporary directory for this test file.
let file = this._globalTemporaryDirectory.clone();
file.append(leafName);
Assert.ok(!file.exists(), "Sanity check the temporary file doesn't exist.");
// Since directory iteration on Windows may not see files that have just
// been created, keep track of the known file names to be removed.
gPathsToRemove.push(file.path);
return file;
},
/**
* Attemps to remove the given file or directory recursively, in a way that
* works even on Windows, where race conditions may occur in the file system
* when creating and removing files at the pace of the test suites.
*
* The function may fail silently if access is denied. This means that it
* should only be used to clean up temporary files, rather than for cases
* where the removal is part of a test and must be guaranteed.
*
* @param path
* String representing the path to remove.
* @param isDir [optional]
* Indicates whether this is a directory. If not specified, this will
* be determined by querying the file system.
*/
async tolerantRemove(path, isDir) {
try {
if (isDir === undefined) {
isDir = (await OS.File.stat(path)).isDir;
}
if (isDir) {
// The test created a directory, remove its contents recursively. The
// deletion may still fail with an access denied error on Windows if any
// of the files in the folder were recently deleted.
await OS.File.removeDir(path);
} else {
// This is the usual case of a test file that has to be removed.
await OS.File.remove(path);
}
} catch (ex) {
// On Windows, we may get an access denied error instead of a no such file
// error if the file existed before, and was recently deleted. There is no
// way to distinguish this from an access list issue because checking for
// the file existence would also result in the same error.
if (
!(ex instanceof OS.File.Error) ||
!(ex.becauseNoSuchFile || ex.becauseAccessDenied)
) {
throw ex;
}
}
},
};
/**
* Returns a reference to a global temporary directory that will be deleted
* when all tests terminate.
*/
XPCOMUtils.defineLazyGetter(
FileTestUtils,
"_globalTemporaryDirectory",
function() {
// While previous test runs should have deleted their temporary directories,
// on Windows they might still be pending deletion on the physical file
// system. This makes a simple nsIFile.createUnique call unreliable, and we
// have to use a random number to make a collision unlikely.
let randomNumber = Math.floor(Math.random() * 1000000);
let dir = FileUtils.getFile("TmpD", ["testdir-" + randomNumber]);
dir.createUnique(Ci.nsIFile.DIRECTORY_TYPE, FileUtils.PERMS_DIRECTORY);
AsyncShutdown.profileBeforeChange.addBlocker(
"Removing test files",
async () => {
// Remove the files we know about first.
for (let path of gPathsToRemove) {
await this.tolerantRemove(path);
}
if (!(await OS.File.exists(dir.path))) {
return;
}
// Detect any extra files, like the ".part" files of downloads.
let iterator = new OS.File.DirectoryIterator(dir.path);
try {
await iterator.forEach(entry =>
this.tolerantRemove(entry.path, entry.isDir)
);
} finally {
iterator.close();
}
// This will fail if any test leaves inaccessible files behind.
await OS.File.removeEmptyDir(dir.path);
}
);
return dir;
}
);