Bug 1771608 - Eliminate mozilla/reject-osfile eslint warning in devTools code r=devtools-reviewers,perftest-reviewers,jdescottes,sparky

## Removed Some Osfile.jsm and ChromeUtils Dependencies

```diff
-  const { OS } = require("resource://gre/modules/osfile.jsm");

And / Or

-  const ChromeUtils = require("ChromeUtils");
```

- devtools/client/memory/actions/io.js
- devtools/client/memory/utils.js
- devtools/client/netmonitor/src/har/har-menu-utils.js
- devtools/client/responsive/test/browser/browser_screenshot_button.js
- devtools/client/shared/remote-debugging/adb/adb-binary.js
- devtools/client/shared/screenshot.js
- devtools/client/styleeditor/StyleEditorUI.jsm
- devtools/client/styleeditor/StyleSheetEditor.jsm
- devtools/client/webconsole/components/Input/JSTerm.js
- devtools/client/webconsole/test/browser/stub-generator-helpers.js
- devtools/server/actors/heap-snapshot-file.js
- devtools/server/actors/storage.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_01.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_02.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_03.js
- devtools/shared/DevToolsUtils.js
- devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js
- devtools/shared/tests/xpcshell/test_fetch-file.js
- testing/talos/talos/tests/devtools/addon/content/tests/toolbox/screenshot.js

## IOUtils.read()

```diff
-  OS.File.read(path);
+  IOUtils.read(path);
```

- devtools/client/aboutdebugging/test/browser/helper-real-usb.js
- devtools/client/netmonitor/src/har/har-menu-utils.js
- devtools/client/shared/remote-debugging/adb/adb-binary.js
- devtools/client/styleeditor/StyleSheetEditor.jsm
- devtools/client/webconsole/components/Input/JSTerm.js
- devtools/client/webconsole/test/browser/browser_jsterm_file_load_save_keyboard_shortcut.js
- devtools/client/webconsole/test/browser/browser_webconsole_context_menu_export_console_output.js
- devtools/shared/DevToolsUtils.js

## IOUtils.write()

```diff
-  OS.File.writeAtomic(filePath, fileContent);
+  IOUtils.write(filePath, fileContent);
```

- devtools/client/webconsole/test/browser/stub-generator-helpers.js
- devtools/shared/DevToolsUtils.js
- devtools/shared/tests/xpcshell/test_fetch-file.js

## PathUtils.split()

```diff
-  OS.Path.split(path);
+  PathUtils.split(path);
```

- devtools/client/styleeditor/StyleSheetEditor.jsm

## PathUtils.join()

```diff
-  OS.Path.join(path, filename);
+  PathUtils.join(path, filename);
```

NOTE: If `filename` is an absolute path then `OS.Path` will ignore `path` and use `filename` but `PathUtils` will try to concatenate both paths. If filename can be an absolute path we need to use `PathUtils.isAbsolute()` and `PathUtils.joinRelative()` to make our desired behaviour explicit.

- devtools/client/debugger/test/mochitest/browser_dbg-chrome-create.js
- devtools/client/shared/remote-debugging/adb/adb-binary.js
- devtools/client/styleeditor/StyleSheetEditor.jsm
- devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js

## PathUtils.isAbsolute() and PathUtils.joinRelative()

```diff
-  filename = OS.Path.join(path, filename);
+  filename = PathUtils.isAbsolute(filename)
+    ? filename
+    : PathUtils.joinRelative(path, filename);
```

- devtools/client/shared/screenshot.js

## IOUtils.remove()

```diff
-  OS.File.remove(filePath);
+  IOUtils.remove(filePath);
```

- devtools/client/framework/test/browser_toolbox_screenshot_tool.js
- devtools/client/responsive/test/browser/browser_screenshot_button.js
- devtools/client/responsive/test/browser/browser_screenshot_button_warning.js
- devtools/client/shared/test/shared-head.js
- devtools/client/webconsole/test/browser/browser_console_screenshot.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_file.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_fixed_header.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_selector.js
- testing/talos/talos/tests/devtools/addon/content/tests/toolbox/screenshot.js

## PathUtils.toFileURI()

```diff
-  OS.Path.toFileURI(filePath);
+  PathUtils.toFileURI(filePath);
```

- devtools/client/framework/test/browser_toolbox_screenshot_tool.js
- devtools/client/responsive/test/browser/browser_screenshot_button.js
- devtools/client/shared/test/shared-head.js
- devtools/client/webconsole/test/browser/browser_console_screenshot.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_file.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_fixed_header.js
- devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_selector.js

## PathUtils.filename()

```diff
-  OS.Path.basename(path),
+  PathUtils.filename(path),
```

- devtools/client/memory/actions/io.js
- devtools/client/memory/utils.js
- devtools/client/styleeditor/StyleEditorUI.jsm
- devtools/client/styleeditor/StyleSheetEditor.jsm

## IOUtils.copy()

```diff
-  OS.File.copy(path, dest);
+  IOUtils.copy(path, dest);
```

- devtools/client/memory/actions/io.js

## IOUtils.stat()

```diff
-  OS.File.stat(filePath);
+  IOUtils.stat(filePath);
```

The objects that these `stat()` versions return differ from one another. This hasn't made much difference to the codebase but our changed usage is included here for completeness:

```diff
-      this._fileModDate = info.lastModificationDate.getTime();
+      this._fileModDate = info.lastModified;
```

- devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js
- devtools/client/memory/test/xpcshell/head.js
- devtools/client/memory/test/xpcshell/test_action-export-snapshot.js
- devtools/client/styleeditor/StyleSheetEditor.jsm
- devtools/server/actors/heap-snapshot-file.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_01.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_02.js
- devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_03.js
- devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js

## IOUtils.setPermissions

```diff
-  OS.File.setPermissions(filePath, { unixMode: 0o744 });
+  IOUtils.setPermissions(filePath, 0o744);
```

- devtools/client/shared/remote-debugging/adb/adb-binary.js

## IOUtils.makeDirectory

```diff
-  OS.File.makeDir(path);
+  IOUtils.makeDirectory(path);
```

- devtools/client/shared/remote-debugging/adb/adb-binary.js

## IOUtils.exists

```diff
-  OS.File.exists(path);
+  IOUtils.exists(path);
```

- devtools/client/shared/remote-debugging/adb/adb-binary.js
- devtools/client/shared/screenshot.js
- devtools/client/webconsole/test/browser/browser_jsterm_file_load_save_keyboard_shortcut.js
- devtools/client/webconsole/test/browser/browser_webconsole_context_menu_export_console_output.js

## PathUtils.profileDir, PathUtils.localProfileDir and PathUtils.tempDir

```diff
-    const profileDir = OS.Constants.Path.profileDir;
+    const profileDir = PathUtils.profileDir;
```

We can reduce reliance on `Osfile.jsm` in another bug bug this is a small step in that direction.

- devtools/client/shared/remote-debugging/adb/adb-binary.js
- devtools/server/actors/storage.js
- devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js

## IOUtils.getChildren(storagePath)

`IOUtils` does not have a direct equivalent of `OS.File.DirectoryIterator()` so we need to iterate more explicitely using `IOUtils.getChildren()`.

```diff
- async findStorageTypePaths(storagePath) {
-   const iterator = new OS.File.DirectoryIterator(storagePath);
-   const typePaths = [];
-
-   await iterator.forEach(entry => {
-     if (entry.isDir) {
-       typePaths.push(entry.path);
-     }
-   });
-
-   iterator.close();
-   return typePaths;
- }

+ async findStorageTypePaths(storagePath) {
+   const children = await IOUtils.getChildren(storagePath);
+   const typePaths = [];
+
+   for (const path of children) {
+     const exists = await IOUtils.exists(path);
+     if (!exists) {
+       continue;
+     }
+
+     const stats = await IOUtils.stat(path);
+     if (stats.type === "directory") {
+       typePaths.push(path);
+     }
+   }
+
+   return typePaths;
+ }

```

- devtools/server/actors/storage.js

## Misc

Made `IOUtils` and `PathUtils` available to DevTools modules.

```diff
   HeapSnapshot,
+  IOUtils,
   L10nRegistry,
   Localization,
   NamedNodeMap,
   NodeFilter,
+  PathUtils,
   StructuredCloneHolder,
   TelemetryStopwatch,
```

- devtools/shared/loader/builtin-modules.js

Differential Revision: https://phabricator.services.mozilla.com/D147589

devtools/client/aboutdebugging/test/browser/helper-real-usb.js

@@ -17,7 +17,7 @@ async function getExpectedRuntimeAll() {
   const currentPath = env.get("PWD");
   const path = `${currentPath}/${runtimesPath}`;
   info(`Load ${path}`);
-  const buffer = await OS.File.read(path);
+  const buffer = await IOUtils.read(path);
   const data = new TextDecoder().decode(buffer);
   return JSON.parse(data);
 }

devtools/client/debugger/test/mochitest/browser_dbg-chrome-create.js

@@ -53,7 +53,7 @@ add_task(async function() {
 
   is(
     gProcess._dbgProfilePath,
-    OS.Path.join(OS.Constants.Path.profileDir, "chrome_debugger_profile"),
+    PathUtils.join(PathUtils.profileDir, "chrome_debugger_profile"),
     "The remote debugger profile isn't where we expect it!"
   );
 

devtools/client/framework/test/browser_toolbox_screenshot_tool.js

@@ -40,7 +40,7 @@ add_task(async function() {
   info("Create an image using the downloaded file as source");
   const image = new Image();
   const onImageLoad = once(image, "load");
-  image.src = OS.Path.toFileURI(filePath);
+  image.src = PathUtils.toFileURI(filePath);
   await onImageLoad;
 
   const dpr = await SpecialPowers.spawn(
@@ -79,6 +79,6 @@ add_task(async function() {
   );
 
   //Remove the downloaded screenshot file
-  await OS.File.remove(filePath);
+  await IOUtils.remove(filePath);
   await resetDownloads();
 });

devtools/client/memory/actions/io.js

@@ -17,7 +17,6 @@ const {
   openFilePicker,
   createSnapshot,
 } = require("devtools/client/memory/utils");
-const { OS } = require("resource://gre/modules/osfile.jsm");
 const {
   selectSnapshot,
   computeSnapshotData,
@@ -29,7 +28,7 @@ exports.pickFileAndExportSnapshot = function(snapshot) {
   return async function({ dispatch, getState }) {
     const outputFile = await openFilePicker({
       title: L10N.getFormatStr("snapshot.io.save.window"),
-      defaultName: OS.Path.basename(snapshot.path),
+      defaultName: PathUtils.filename(snapshot.path),
       filters: [[L10N.getFormatStr("snapshot.io.filter"), "*.fxsnapshot"]],
       mode: "save",
     });
@@ -52,7 +51,7 @@ const exportSnapshot = (exports.exportSnapshot = function(snapshot, dest) {
     );
 
     try {
-      await OS.File.copy(snapshot.path, dest);
+      await IOUtils.copy(snapshot.path, dest);
     } catch (error) {
       reportException("exportSnapshot", error);
       dispatch({ type: actions.EXPORT_SNAPSHOT_ERROR, snapshot, error });

devtools/client/memory/test/browser/browser_memory_transferHeapSnapshot_e10s_01.js

@@ -22,7 +22,7 @@ this.test = makeMemoryTest(TEST_URL, async function({ tab, panel }) {
   });
 
   ok(
-    !!(await OS.File.stat(snapshotFilePath)),
+    !!(await IOUtils.stat(snapshotFilePath)),
     "Should have the heap snapshot file"
   );
 

devtools/client/memory/test/xpcshell/head.js

@@ -137,7 +137,7 @@ async function createTempFile() {
   const file = FileUtils.getFile("TmpD", ["tmp.fxsnapshot"]);
   file.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, FileUtils.PERMS_FILE);
   const destPath = file.path;
-  const stat = await OS.File.stat(destPath);
+  const stat = await IOUtils.stat(destPath);
   ok(stat.size === 0, "new file is 0 bytes at start");
   return destPath;
 }

devtools/client/memory/test/xpcshell/test_action-export-snapshot.js

@@ -31,7 +31,7 @@ add_task(async function() {
   dispatch(exportSnapshot(getState().snapshots[0], destPath));
   await exportEvents;
 
-  const stat = await OS.File.stat(destPath);
+  const stat = await IOUtils.stat(destPath);
   info(stat.size);
   ok(stat.size > 0, "destination file is more than 0 bytes");
 

devtools/client/memory/utils.js

@@ -10,7 +10,6 @@ const { LocalizationHelper } = require("devtools/shared/l10n");
 const STRINGS_URI = "devtools/client/locales/memory.properties";
 const L10N = (exports.L10N = new LocalizationHelper(STRINGS_URI));
 
-const { OS } = require("resource://gre/modules/osfile.jsm");
 const { assert } = require("devtools/shared/DevToolsUtils");
 const { Preferences } = require("resource://gre/modules/Preferences.jsm");
 const CUSTOM_CENSUS_DISPLAY_PREF = "devtools.memory.custom-census-displays";
@@ -43,7 +42,7 @@ exports.getSnapshotTitle = function(snapshot) {
 
   if (snapshot.imported) {
     // Strip out the extension if it's the expected ".fxsnapshot"
-    return OS.Path.basename(snapshot.path.replace(/\.fxsnapshot$/, ""));
+    return PathUtils.filename(snapshot.path.replace(/\.fxsnapshot$/, ""));
   }
 
   const date = new Date(snapshot.creationTime / 1000);

devtools/client/netmonitor/src/har/har-menu-utils.js

@@ -4,7 +4,6 @@
 
 "use strict";
 
-const ChromeUtils = require("ChromeUtils");
 const { L10N } = require("devtools/client/netmonitor/src/utils/l10n");
 
 loader.lazyRequireGetter(
@@ -94,8 +93,7 @@ var HarMenuUtils = {
 
 function readFile(file) {
   return new Promise(resolve => {
-    const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
-    OS.File.read(file.path).then(data => {
+    IOUtils.read(file.path).then(data => {
       const decoder = new TextDecoder();
       resolve(decoder.decode(data));
     });

devtools/client/responsive/test/browser/browser_screenshot_button.js

@@ -7,8 +7,6 @@
 
 const TEST_URL = "data:text/html;charset=utf-8,";
 
-const { OS } = require("resource://gre/modules/osfile.jsm");
-
 addRDMTask(TEST_URL, async function({ ui }) {
   const { toolWindow } = ui;
   const { store, document } = toolWindow;
@@ -21,7 +19,7 @@ addRDMTask(TEST_URL, async function({ ui }) {
 
   const filePath = await whenScreenshotSucceeded;
   const image = new Image();
-  image.src = OS.Path.toFileURI(filePath);
+  image.src = PathUtils.toFileURI(filePath);
 
   await once(image, "load");
 
@@ -41,5 +39,5 @@ addRDMTask(TEST_URL, async function({ ui }) {
     "screenshot width has the expected height"
   );
 
-  await OS.File.remove(filePath);
+  await IOUtils.remove(filePath);
 });

devtools/client/responsive/test/browser/browser_screenshot_button_warning.js

@@ -52,7 +52,7 @@ addRDMTask(
     );
 
     //Remove the downloaded screenshot file
-    await OS.File.remove(filePath);
+    await IOUtils.remove(filePath);
     await resetDownloads();
   },
   { waitForDeviceList: true }

devtools/client/shared/remote-debugging/adb/adb-binary.js

@@ -6,7 +6,6 @@
 
 const { dumpn } = require("devtools/shared/DevToolsUtils");
 
-loader.lazyImporter(this, "OS", "resource://gre/modules/osfile.jsm");
 loader.lazyImporter(
   this,
   "ExtensionParent",
@@ -26,13 +25,13 @@ loader.lazyRequireGetter(
   true
 );
 loader.lazyGetter(this, "UNPACKED_ROOT_PATH", () => {
-  return OS.Path.join(OS.Constants.Path.localProfileDir, "adb");
+  return PathUtils.join(PathUtils.localProfileDir, "adb");
 });
 loader.lazyGetter(this, "EXTENSION_ID", () => {
   return Services.prefs.getCharPref("devtools.remote.adb.extensionID");
 });
 loader.lazyGetter(this, "ADB_BINARY_PATH", () => {
-  let adbBinaryPath = OS.Path.join(UNPACKED_ROOT_PATH, "adb");
+  let adbBinaryPath = PathUtils.join(UNPACKED_ROOT_PATH, "adb");
   if (Services.appinfo.OS === "WINNT") {
     adbBinaryPath += ".exe";
   }
@@ -83,7 +82,7 @@ async function unpackFile(file) {
 
   // Assumes that destination dir already exists.
   const basePath = file.substring(file.lastIndexOf("/") + 1);
-  const filePath = OS.Path.join(UNPACKED_ROOT_PATH, basePath);
+  const filePath = PathUtils.join(UNPACKED_ROOT_PATH, basePath);
   await new Promise((resolve, reject) => {
     NetUtil.asyncFetch(
       {
@@ -93,7 +92,7 @@ async function unpackFile(file) {
       input => {
         try {
           // Since we have to use NetUtil to read, probably it's okay to use for
-          // writing, rather than bouncing to OS.File...?
+          // writing, rather than bouncing to IOUtils...?
           const outputFile = new FileUtils.File(filePath);
           const output = FileUtils.openAtomicFileOutputStream(outputFile);
           NetUtil.asyncCopy(input, output, resolve);
@@ -105,7 +104,7 @@ async function unpackFile(file) {
     );
   });
   // Mark binaries as executable.
-  await OS.File.setPermissions(filePath, { unixMode: 0o744 });
+  await IOUtils.setPermissions(filePath, 0o744);
 }
 
 /**
@@ -154,7 +153,7 @@ async function extractFiles() {
   // comparison
   filesForAdb.push(MANIFEST);
 
-  await OS.File.makeDir(UNPACKED_ROOT_PATH);
+  await IOUtils.makeDirectory(UNPACKED_ROOT_PATH);
 
   for (const file of filesForAdb) {
     try {
@@ -185,21 +184,21 @@ async function getManifestFromExtension() {
  * Returns whether manifest.json has already been unpacked.
  */
 async function isManifestUnpacked() {
-  const manifestPath = OS.Path.join(UNPACKED_ROOT_PATH, MANIFEST);
-  return OS.File.exists(manifestPath);
+  const manifestPath = PathUtils.join(UNPACKED_ROOT_PATH, MANIFEST);
+  return IOUtils.exists(manifestPath);
 }
 
 /**
  * Read the manifest from the unpacked binary directory.
- * Uses OS.File since this is a local file.
+ * Uses IOUtils since this is a local file.
  */
 async function getManifestFromUnpacked() {
   if (!(await isManifestUnpacked())) {
     throw new Error("Manifest doesn't exist at unpacked path");
   }
 
-  const manifestPath = OS.Path.join(UNPACKED_ROOT_PATH, MANIFEST);
-  const binary = await OS.File.read(manifestPath);
+  const manifestPath = PathUtils.join(UNPACKED_ROOT_PATH, MANIFEST);
+  const binary = await IOUtils.read(manifestPath);
   const json = new TextDecoder().decode(binary);
   let data;
   try {

devtools/client/shared/screenshot.js

@@ -9,7 +9,6 @@ const { LocalizationHelper } = require("devtools/shared/l10n");
 const Services = require("Services");
 
 loader.lazyImporter(this, "Downloads", "resource://gre/modules/Downloads.jsm");
-loader.lazyImporter(this, "OS", "resource://gre/modules/osfile.jsm");
 loader.lazyImporter(this, "FileUtils", "resource://gre/modules/FileUtils.jsm");
 
 const STRINGS_URI = "devtools/shared/locales/screenshot.properties";
@@ -347,11 +346,13 @@ async function saveToFile(image) {
   }
 
   const downloadsDir = await Downloads.getPreferredDownloadsDirectory();
-  const downloadsDirExists = await OS.File.exists(downloadsDir);
+  const downloadsDirExists = await IOUtils.exists(downloadsDir);
   if (downloadsDirExists) {
     // If filename is absolute, it will override the downloads directory and
     // still be applied as expected.
-    filename = OS.Path.join(downloadsDir, filename);
+    filename = PathUtils.isAbsolute(filename)
+      ? filename
+      : PathUtils.joinRelative(downloadsDir, filename);
   }
 
   const sourceURI = Services.io.newURI(image.data);

devtools/client/shared/test/shared-head.js

@@ -1580,11 +1580,11 @@ async function takeNodeScreenshot(inspector) {
   info("Create an image using the downloaded fileas source");
   const image = new Image();
   const onImageLoad = once(image, "load");
-  image.src = OS.Path.toFileURI(filePath);
+  image.src = PathUtils.toFileURI(filePath);
   await onImageLoad;
 
   info("Remove the downloaded screenshot file");
-  await OS.File.remove(filePath);
+  await IOUtils.remove(filePath);
 
   // See intermittent Bug 1508435. Even after removing the file, tests still manage to
   // reuse files from the previous test if they have the same name. Since our file name

devtools/client/styleeditor/StyleEditorUI.jsm

@@ -51,8 +51,6 @@ loader.lazyRequireGetter(
   "resource://gre/modules/NetUtil.jsm",
   true
 );
-loader.lazyRequireGetter(this, "OS", "resource://gre/modules/osfile.jsm", true);
-
 loader.lazyRequireGetter(
   this,
   "ResponsiveUIManager",
@@ -1239,7 +1237,7 @@ class StyleEditorUI extends EventEmitter {
 
     let linkedCSSSource = "";
     if (editor.linkedCSSFile) {
-      linkedCSSSource = OS.Path.basename(editor.linkedCSSFile);
+      linkedCSSSource = PathUtils.filename(editor.linkedCSSFile);
     } else if (editor.styleSheet.relatedEditorName) {
       linkedCSSSource = editor.styleSheet.relatedEditorName;
     }

devtools/client/styleeditor/StyleSheetEditor.jsm

@@ -30,7 +30,6 @@ loader.lazyRequireGetter(
   "resource://gre/modules/NetUtil.jsm",
   true
 );
-loader.lazyRequireGetter(this, "OS", "resource://gre/modules/osfile.jsm", true);
 
 const {
   getString,
@@ -263,8 +262,8 @@ StyleSheetEditor.prototype = {
     this.linkedCSSFileError = null;
 
     // save last file change time so we can compare when we check for changes.
-    OS.File.stat(path).then(info => {
-      this._fileModDate = info.lastModificationDate.getTime();
+    IOUtils.stat(path).then(info => {
+      this._fileModDate = info.lastModified;
     }, this.markLinkedFileBroken);
 
     this.emit("linked-css-file");
@@ -777,7 +776,9 @@ StyleSheetEditor.prototype = {
 
     let defaultName;
     if (this._friendlyName) {
-      defaultName = OS.Path.basename(this._friendlyName);
+      defaultName = PathUtils.isAbsolute(this._friendlyName)
+        ? PathUtils.filename(this._friendlyName)
+        : this._friendlyName;
     }
     showFilePicker(
       file || this._styleSheetFilePath,
@@ -818,8 +819,8 @@ StyleSheetEditor.prototype = {
    * if so, update the live style sheet.
    */
   checkLinkedFileForChanges: function() {
-    OS.File.stat(this.linkedCSSFile).then(info => {
-      const lastChange = info.lastModificationDate.getTime();
+    IOUtils.stat(this.linkedCSSFile).then(info => {
+      const lastChange = info.lastModified;
 
       if (this._fileModDate && lastChange != this._fileModDate) {
         this._fileModDate = lastChange;
@@ -866,7 +867,7 @@ StyleSheetEditor.prototype = {
    * file from disk and live update the stylesheet object with the contents.
    */
   updateLinkedStyleSheet: function() {
-    OS.File.read(this.linkedCSSFile).then(async array => {
+    IOUtils.read(this.linkedCSSFile).then(async array => {
       const decoder = new TextDecoder();
       const text = decoder.decode(array);
 
@@ -957,7 +958,7 @@ function findLinkedFilePath(uri, origUri, file) {
   const project = findProjectPath(file, origBranch);
 
   const parts = project.concat(branch);
-  const path = OS.Path.join.apply(this, parts);
+  const path = PathUtils.join.apply(this, parts);
 
   return path;
 }
@@ -976,7 +977,7 @@ function findLinkedFilePath(uri, origUri, file) {
  *        array of path parts
  */
 function findProjectPath(file, branch) {
-  const path = OS.Path.split(file.path).components;
+  const path = PathUtils.split(file.path);
 
   for (let i = 2; i <= branch.length; i++) {
     // work backwards until we find a differing directory name
@@ -1002,8 +1003,8 @@ function findProjectPath(file, branch) {
  *         object with 'branch' and 'origBranch' array of path parts for branch
  */
 function findUnsharedBranches(origUri, uri) {
-  origUri = OS.Path.split(origUri.pathQueryRef).components;
-  uri = OS.Path.split(uri.pathQueryRef).components;
+  origUri = PathUtils.split(origUri.pathQueryRef);
+  uri = PathUtils.split(uri.pathQueryRef);
 
   for (let i = 0; i < uri.length - 1; i++) {
     if (uri[i] != origUri[i]) {

devtools/client/webconsole/components/Input/JSTerm.js

@@ -4,7 +4,6 @@
 
 "use strict";
 
-const ChromeUtils = require("ChromeUtils");
 const Services = require("Services");
 const { debounce } = require("devtools/shared/debounce");
 const isMacOS = Services.appinfo.OS === "Darwin";
@@ -761,8 +760,7 @@ class JSTerm extends Component {
 
     function readFile(file) {
       return new Promise(resolve => {
-        const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
-        OS.File.read(file.path).then(data => {
+        IOUtils.read(file.path).then(data => {
           const decoder = new TextDecoder();
           resolve(decoder.decode(data));
         });

devtools/client/webconsole/test/browser/browser_console_screenshot.js

@@ -54,7 +54,7 @@ add_task(async function() {
 
   info("Create an image using the downloaded file as source");
   const image = new Image();
-  image.src = OS.Path.toFileURI(file.path);
+  image.src = PathUtils.toFileURI(file.path);
   await once(image, "load");
 
   info(
@@ -106,6 +106,6 @@ add_task(async function() {
   });
 
   info("Remove the downloaded screenshot file and cleanup downloads");
-  await OS.File.remove(file.path);
+  await IOUtils.remove(file.path);
   await resetDownloads();
 });

devtools/client/webconsole/test/browser/browser_jsterm_file_load_save_keyboard_shortcut.js

@@ -56,8 +56,8 @@ add_task(async function() {
     [isMacOS ? "metaKey" : "ctrlKey"]: true,
   });
 
-  await waitFor(() => OS.File.exists(nsiFile.path));
-  const buffer = await OS.File.read(nsiFile.path);
+  await waitFor(() => IOUtils.exists(nsiFile.path));
+  const buffer = await IOUtils.read(nsiFile.path);
   const fileContent = new TextDecoder().decode(buffer);
   is(
     fileContent,

devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_file.js

@@ -45,7 +45,7 @@ add_task(async function() {
 
   info("Create an image using the downloaded file as source");
   const image = new Image();
-  image.src = OS.Path.toFileURI(file.path);
+  image.src = PathUtils.toFileURI(file.path);
   await once(image, "load");
 
   // The page has the following structure
@@ -113,6 +113,6 @@ add_task(async function() {
   );
 
   info("Remove the downloaded screenshot file and cleanup downloads");
-  await OS.File.remove(file.path);
+  await IOUtils.remove(file.path);
   await resetDownloads();
 });

devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_fixed_header.js

@@ -40,7 +40,7 @@ add_task(async function() {
 
   info("Create an image using the downloaded file as source");
   const image = new Image();
-  image.src = OS.Path.toFileURI(actualFilePath);
+  image.src = PathUtils.toFileURI(actualFilePath);
   await once(image, "load");
 
   info("Check that the fixed element is rendered at the expected position");
@@ -67,6 +67,6 @@ add_task(async function() {
   );
 
   info("Remove the downloaded screenshot file and cleanup downloads");
-  await OS.File.remove(actualFilePath);
+  await IOUtils.remove(actualFilePath);
   await resetDownloads();
 });

devtools/client/webconsole/test/browser/browser_jsterm_screenshot_command_selector.js

@@ -52,7 +52,7 @@ add_task(async function() {
 
   info("Create an image using the downloaded file as source");
   let image = new Image();
-  image.src = OS.Path.toFileURI(sameOriginIframeScreenshotFile.path);
+  image.src = PathUtils.toFileURI(sameOriginIframeScreenshotFile.path);
   await once(image, "load");
 
   info("Check that the node was rendered as expected in the screenshot");
@@ -65,7 +65,7 @@ add_task(async function() {
   });
 
   // Remove the downloaded screenshot file and cleanup downloads
-  await OS.File.remove(sameOriginIframeScreenshotFile.path);
+  await IOUtils.remove(sameOriginIframeScreenshotFile.path);
   await resetDownloads();
 
   info("Check using :screenshot --selector in a remote-iframe context");
@@ -114,7 +114,7 @@ add_task(async function() {
 
   info("Create an image using the downloaded file as source");
   image = new Image();
-  image.src = OS.Path.toFileURI(remoteIframeSpanScreenshot.path);
+  image.src = PathUtils.toFileURI(remoteIframeSpanScreenshot.path);
   await once(image, "load");
 
   info("Check that the node was rendered as expected in the screenshot");
@@ -141,6 +141,6 @@ add_task(async function() {
   );
 
   // Remove the downloaded screenshot file and cleanup downloads
-  await OS.File.remove(remoteIframeSpanScreenshot.path);
+  await IOUtils.remove(remoteIframeSpanScreenshot.path);
   await resetDownloads();
 });

devtools/client/webconsole/test/browser/browser_webconsole_context_menu_export_console_output.js

@@ -161,8 +161,8 @@ async function exportAllToFile(hud, message) {
   menuPopup.hidePopup();
 
   // The file may not be ready yet.
-  await waitFor(() => OS.File.exists(nsiFile.path));
-  const buffer = await OS.File.read(nsiFile.path);
+  await waitFor(() => IOUtils.exists(nsiFile.path));
+  const buffer = await IOUtils.read(nsiFile.path);
   return new TextDecoder().decode(buffer);
 }
 

devtools/client/webconsole/test/browser/stub-generator-helpers.js

@@ -3,9 +3,6 @@
 
 "use strict";
 
-const ChromeUtils = require("ChromeUtils");
-const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
-
 const {
   getAdHocFrontOrPrimitiveGrip,
 } = require("devtools/client/fronts/object");
@@ -305,7 +302,7 @@ module.exports = {
 };
 `;
 
-  await OS.File.writeAtomic(filePath, fileContent);
+  await IOUtils.write(filePath, fileContent);
 }
 
 function getStubFile(fileName) {

devtools/server/actors/heap-snapshot-file.js

@@ -16,7 +16,6 @@ loader.lazyRequireGetter(
   "DevToolsUtils",
   "devtools/shared/DevToolsUtils"
 );
-loader.lazyRequireGetter(this, "OS", "resource://gre/modules/osfile.jsm", true);
 loader.lazyRequireGetter(
   this,
   "HeapSnapshotFileUtils",
@@ -64,7 +63,7 @@ exports.HeapSnapshotFileActor = protocol.ActorClassWithSpec(
 
       const streamPromise = DevToolsUtils.openFileStream(snapshotFilePath);
 
-      const { size } = await OS.File.stat(snapshotFilePath);
+      const { size } = await IOUtils.stat(snapshotFilePath);
       const bulkPromise = this.conn.startBulkSend({
         actor: this.actorID,
         type: "heap-snapshot",

devtools/server/actors/storage.js

@@ -49,7 +49,6 @@ const SAFE_HOSTS_PREFIXES_REGEX = /^(about\+|https?\+|file\+|moz-extension\+)/;
 // devtools/server/tests/browser/head.js
 const SEPARATOR_GUID = "{9d414cc5-8319-0a04-0586-c0a6ae01670a}";
 
-loader.lazyImporter(this, "OS", "resource://gre/modules/osfile.jsm");
 loader.lazyImporter(this, "Sqlite", "resource://gre/modules/Sqlite.jsm");
 
 // We give this a funny name to avoid confusion with the global
@@ -2900,17 +2899,26 @@ var indexedDBHelpers = {
    * the browser.
    */
   async getInternalHosts() {
-    const profileDir = OS.Constants.Path.profileDir;
-    const storagePath = OS.Path.join(profileDir, "storage", "permanent");
-    const iterator = new OS.File.DirectoryIterator(storagePath);
+    const profileDir = PathUtils.profileDir;
+    const storagePath = PathUtils.join(profileDir, "storage", "permanent");
+    const children = await IOUtils.getChildren(storagePath);
     const hosts = [];
 
-    await iterator.forEach(entry => {
-      if (entry.isDir && !SAFE_HOSTS_PREFIXES_REGEX.test(entry.name)) {
-        hosts.push(entry.name);
+    for (const path of children) {
+      const exists = await IOUtils.exists(path);
+      if (!exists) {
+        continue;
       }
-    });
-    iterator.close();
+
+      const stats = await IOUtils.stat(path);
+      if (
+        stats.type === "directory" &&
+        !SAFE_HOSTS_PREFIXES_REGEX.test(stats.path)
+      ) {
+        const basename = PathUtils.filename(path);
+        hosts.push(basename);
+      }
+    }
 
     return this.backToChild("getInternalHosts", hosts);
   },
@@ -3034,10 +3042,10 @@ var indexedDBHelpers = {
    */
   async getDBNamesForHost(host, principal) {
     const sanitizedHost = this.getSanitizedHost(host) + principal.originSuffix;
-    const profileDir = OS.Constants.Path.profileDir;
+    const profileDir = PathUtils.profileDir;
+    const storagePath = PathUtils.join(profileDir, "storage");
     const files = [];
     const names = [];
-    const storagePath = OS.Path.join(profileDir, "storage");
 
     // We expect sqlite DB paths to look something like this:
     // - PathToProfileDir/storage/default/http+++www.example.com/
@@ -3057,7 +3065,7 @@ var indexedDBHelpers = {
     );
 
     for (const file of sqliteFiles) {
-      const splitPath = OS.Path.split(file).components;
+      const splitPath = PathUtils.split(file);
       const idbIndex = splitPath.indexOf("idb");
       const storage = splitPath[idbIndex - 2];
       const relative = file.substr(profileDir.length + 1);
@@ -3091,13 +3099,19 @@ var indexedDBHelpers = {
     const sqlitePaths = [];
     const idbPaths = await this.findIDBPathsForHost(storagePath, sanitizedHost);
     for (const idbPath of idbPaths) {
-      const iterator = new OS.File.DirectoryIterator(idbPath);
-      await iterator.forEach(entry => {
-        if (!entry.isDir && entry.path.endsWith(".sqlite")) {
-          sqlitePaths.push(entry.path);
+      const children = await IOUtils.getChildren(idbPath);
+
+      for (const path of children) {
+        const exists = await IOUtils.exists(path);
+        if (!exists) {
+          continue;
         }
-      });
-      iterator.close();
+
+        const stats = await IOUtils.stat(path);
+        if (stats.type !== "directory" && stats.path.endsWith(".sqlite")) {
+          sqlitePaths.push(path);
+        }
+      }
     }
     return sqlitePaths;
   },
@@ -3110,8 +3124,8 @@ var indexedDBHelpers = {
     const idbPaths = [];
     const typePaths = await this.findStorageTypePaths(storagePath);
     for (const typePath of typePaths) {
-      const idbPath = OS.Path.join(typePath, sanitizedHost, "idb");
-      if (await OS.File.exists(idbPath)) {
+      const idbPath = PathUtils.join(typePath, sanitizedHost, "idb");
+      if (await IOUtils.exists(idbPath)) {
         idbPaths.push(idbPath);
       }
     }
@@ -3124,14 +3138,21 @@ var indexedDBHelpers = {
    * types that currently exist in the profile.
    */
   async findStorageTypePaths(storagePath) {
-    const iterator = new OS.File.DirectoryIterator(storagePath);
+    const children = await IOUtils.getChildren(storagePath);
     const typePaths = [];
-    await iterator.forEach(entry => {
-      if (entry.isDir) {
-        typePaths.push(entry.path);
+
+    for (const path of children) {
+      const exists = await IOUtils.exists(path);
+      if (!exists) {
+        continue;
       }
-    });
-    iterator.close();
+
+      const stats = await IOUtils.stat(path);
+      if (stats.type === "directory") {
+        typePaths.push(path);
+      }
+    }
+
     return typePaths;
   },
 

devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_01.js

@@ -6,14 +6,12 @@
 // Test that we can tell the memory actor to take a heap snapshot over the RDP
 // and then create a HeapSnapshot instance from the resulting file.
 
-const { OS } = require("resource://gre/modules/osfile.jsm");
-
 add_task(async () => {
   const { memoryFront } = await createTabMemoryFront();
 
   const snapshotFilePath = await memoryFront.saveHeapSnapshot();
   ok(
-    !!(await OS.File.stat(snapshotFilePath)),
+    !!(await IOUtils.stat(snapshotFilePath)),
     "Should have the heap snapshot file"
   );
   const snapshot = ChromeUtils.readHeapSnapshot(snapshotFilePath);

devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_02.js

@@ -6,8 +6,6 @@
 // Test that we can properly stream heap snapshot files over the RDP as bulk
 // data.
 
-const { OS } = require("resource://gre/modules/osfile.jsm");
-
 add_task(async () => {
   const { memoryFront } = await createTabMemoryFront();
 
@@ -15,7 +13,7 @@ add_task(async () => {
     forceCopy: true,
   });
   ok(
-    !!(await OS.File.stat(snapshotFilePath)),
+    !!(await IOUtils.stat(snapshotFilePath)),
     "Should have the heap snapshot file"
   );
   const snapshot = ChromeUtils.readHeapSnapshot(snapshotFilePath);

devtools/server/tests/xpcshell/test_MemoryActor_saveHeapSnapshot_03.js

@@ -6,14 +6,12 @@
 // Test that we can save full runtime heap snapshots when attached to the
 // ParentProcessTargetActor or a ContentProcessTargetActor.
 
-const { OS } = require("resource://gre/modules/osfile.jsm");
-
 add_task(async () => {
   const { memoryFront } = await createMainProcessMemoryFront();
 
   const snapshotFilePath = await memoryFront.saveHeapSnapshot();
   ok(
-    !!(await OS.File.stat(snapshotFilePath)),
+    !!(await IOUtils.stat(snapshotFilePath)),
     "Should have the heap snapshot file"
   );
   const snapshot = ChromeUtils.readHeapSnapshot(snapshotFilePath);

devtools/shared/DevToolsUtils.js

@@ -493,10 +493,6 @@ DevToolsUtils.defineLazyGetter(this, "NetUtil", () => {
   return require("resource://gre/modules/NetUtil.jsm").NetUtil;
 });
 
-DevToolsUtils.defineLazyGetter(this, "OS", () => {
-  return require("resource://gre/modules/osfile.jsm").OS;
-});
-
 DevToolsUtils.defineLazyGetter(this, "NetworkHelper", () => {
   return require("devtools/shared/webconsole/network-helper");
 });
@@ -669,12 +665,12 @@ function mainThreadFetch(
           ex.name === "NS_BASE_STREAM_CLOSED" &&
           uri instanceof Ci.nsIFileURL
         ) {
-          // Empty files cause NS_BASE_STREAM_CLOSED exception. Use OS.File to
+          // Empty files cause NS_BASE_STREAM_CLOSED exception. Use IOUtils to
           // differentiate between empty files and other errors (bug 1170864).
           // This can be removed when bug 982654 is fixed.
 
           uri.QueryInterface(Ci.nsIFileURL);
-          const result = OS.File.read(uri.file.path).then(bytes => {
+          const result = IOUtils.read(uri.file.path).then(bytes => {
             // Convert the bytearray to a String.
             const decoder = new TextDecoder();
             const content = decoder.decode(bytes);
@@ -846,7 +842,7 @@ exports.saveAs = async function(
     return;
   }
 
-  await OS.File.writeAtomic(returnFile.path, dataArray, {
+  await IOUtils.write(returnFile.path, dataArray, {
     tmpPath: returnFile.path + ".tmp",
   });
 };

devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js

@@ -29,10 +29,9 @@ loader.lazyRequireGetter(
   "resource://gre/modules/FileUtils.jsm",
   true
 );
-loader.lazyRequireGetter(this, "OS", "resource://gre/modules/osfile.jsm", true);
 
 function getHeapSnapshotFileTemplate() {
-  return OS.Path.join(OS.Constants.Path.tmpDir, `${Date.now()}.fxsnapshot`);
+  return PathUtils.join(PathUtils.osTempDir, `${Date.now()}.fxsnapshot`);
 }
 
 /**
@@ -67,7 +66,7 @@ exports.getHeapSnapshotTempFilePath = function(snapshotId) {
   if (!isValidSnapshotFileId(snapshotId)) {
     return null;
   }
-  return OS.Path.join(OS.Constants.Path.tmpDir, snapshotId + ".fxsnapshot");
+  return PathUtils.join(PathUtils.osTempDir, snapshotId + ".fxsnapshot");
 };
 
 /**
@@ -82,7 +81,7 @@ exports.haveHeapSnapshotTempFile = function(snapshotId) {
     return Promise.resolve(false);
   }
 
-  return OS.File.stat(path).then(
+  return IOUtils.stat(path).then(
     () => true,
     () => false
   );

devtools/shared/loader/builtin-modules.js

@@ -32,10 +32,12 @@ const {
   DOMQuad,
   DOMRect,
   HeapSnapshot,
+  IOUtils,
   L10nRegistry,
   Localization,
   NamedNodeMap,
   NodeFilter,
+  PathUtils,
   StructuredCloneHolder,
   TelemetryStopwatch,
 } = Cu.getGlobalForObject(jsmScope);
@@ -275,6 +277,7 @@ exports.globals = {
   Element,
   FileReader,
   FormData,
+  IOUtils,
   isWorker: false,
   L10nRegistry,
   loader: {
@@ -287,6 +290,7 @@ exports.globals = {
   },
   Localization,
   Node,
+  PathUtils,
   reportError: Cu.reportError,
   StructuredCloneHolder,
   TextDecoder,

devtools/shared/tests/xpcshell/test_fetch-file.js

@@ -7,7 +7,6 @@
 const { FileUtils } = ChromeUtils.import(
   "resource://gre/modules/FileUtils.jsm"
 );
-const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
 
 const TEST_CONTENT = "aéd";
 
@@ -26,7 +25,7 @@ add_task(async function test_arrow_urls() {
   const { path } = createTemporaryFile(".js");
   const url = "resource://gre/modules/XPIProvider.jsm -> file://" + path;
 
-  await OS.File.writeAtomic(path, TEST_CONTENT, { encoding: "utf-8" });
+  await IOUtils.writeUTF8(path, TEST_CONTENT);
   const { content } = await DevToolsUtils.fetch(url);
 
   deepEqual(content, TEST_CONTENT, "The file contents were correctly read.");
@@ -46,7 +45,7 @@ add_task(async function test_empty() {
  */
 add_task(async function test_encoding_utf8() {
   const { path } = createTemporaryFile();
-  await OS.File.writeAtomic(path, UTF8_TEST_BUFFER);
+  await IOUtils.write(path, UTF8_TEST_BUFFER);
 
   const { content } = await DevToolsUtils.fetch(path);
   deepEqual(
@@ -61,7 +60,7 @@ add_task(async function test_encoding_utf8() {
  */
 add_task(async function test_encoding_iso_8859_1() {
   const { path } = createTemporaryFile();
-  await OS.File.writeAtomic(path, ISO_8859_1_BUFFER);
+  await IOUtils.write(path, ISO_8859_1_BUFFER);
 
   const { content } = await DevToolsUtils.fetch(path);
   deepEqual(
@@ -92,7 +91,7 @@ add_task(async function test_missing() {
 add_task(async function test_schemeless_files() {
   const { path } = createTemporaryFile();
 
-  await OS.File.writeAtomic(path, TEST_CONTENT, { encoding: "utf-8" });
+  await IOUtils.writeUTF8(path, TEST_CONTENT);
 
   const { content } = await DevToolsUtils.fetch(path);
   deepEqual(content, TEST_CONTENT, "The content was correct.");

testing/talos/talos/tests/devtools/addon/content/tests/toolbox/screenshot.js

@@ -12,7 +12,6 @@ const {
   testSetup,
   testTeardown,
 } = require("damp-test/tests/head");
-const { OS } = require("resource://gre/modules/osfile.jsm");
 const { Downloads } = require("resource://gre/modules/Downloads.jsm");
 const Services = require("Services");
 
@@ -32,8 +31,8 @@ module.exports = async function() {
   const filePath = await onScreenshotDownloaded;
   test.done();
 
-  //Remove the downloaded screenshot file
-  await OS.File.remove(filePath);
+  // Remove the downloaded screenshot file
+  await IOUtils.remove(filePath);
 
   // ⚠️ Even after removing the file, the test could still manage to reuse files from the
   // previous test run if they have the same name. Since the screenshot file name is based