docs: categorize breaking changes (#22834)

Co-authored-by: John Kleinschmidt <[email protected]>

docs/breaking-changes.md

@@ -2,13 +2,19 @@
 
 Breaking changes will be documented here, and deprecation warnings added to JS code where possible, at least [one major version](tutorial/electron-versioning.md#semver) before the change is made.
 
-## `FIXME` comments
+### Types of Breaking Changes
 
-The `FIXME` string is used in code comments to denote things that should be fixed for future releases. See https://github.com/electron/electron/search?q=fixme
+This document uses the following convention to categorize breaking changes:
+
+- **API Changed:** An API was changed in such a way that code that has not been updated is guaranteed to throw an exception.
+- **Behavior Changed:** The behavior of Electron has changed, but not in such a way that an exception will necessarily be thrown.
+- **Default Changed:** Code depending on the old default may break, not necessarily throwing an exception. The old behavior can be restored by explicitly specifying the value.
+- **Deprecated:** An API was marked as deprecated. The API will continue to function, but will emit a deprecation warning, and will be removed in a future release.
+- **Removed:** An API or feature was removed, and is no longer supported by Electron.
 
 ## Planned Breaking API Changes (10.0)
 
-### Browser Window Affinity
+### Removed: Browser Window Affinity
 
 The `affinity` option when constructing a new `BrowserWindow` will be removed
 as part of our plan to more closely align with Chromiums process model for security,
@@ -16,7 +22,7 @@ performance and maintainability.
 
 For more detailed information see [#18397](https://github.com/electron/electron/issues/18397).
 
-### `enableRemoteModule` defaults to `false`
+### Default Changed: `enableRemoteModule` defaults to `false`
 
 In Electron 9, using the remote module without explicitly enabling it via the
 `enableRemoteModule` WebPreferences option began emitting a warning. In
@@ -36,7 +42,7 @@ module](https://medium.com/@nornagon/electrons-remote-module-considered-harmful-
 
 ## Planned Breaking API Changes (9.0)
 
-### Loading non-context-aware native modules in the renderer process
+### Default Changed: Loading non-context-aware native modules in the renderer process is disabled by default
 
 As of Electron 9 we do not allow loading of non-context-aware native modules in
 the renderer process.  This is to improve security, performance and maintainability
@@ -48,7 +54,7 @@ you should plan to update your native modules to be context aware.
 
 For more detailed information see [#18397](https://github.com/electron/electron/issues/18397).
 
-### `<webview>.getWebContents()`
+### Removed: `<webview>.getWebContents()`
 
 This API, which was deprecated in Electron 8.0, is now removed.
 
@@ -60,7 +66,7 @@ const { remote } = require('electron')
 remote.webContents.fromId(webview.getWebContentsId())
 ```
 
-### `webFrame.setLayoutZoomLevelLimits()`
+### Removed: `webFrame.setLayoutZoomLevelLimits()`
 
 Chromium has removed support for changing the layout zoom level limits, and it
 is beyond Electron's capacity to maintain it. The function was deprecated in
@@ -68,7 +74,7 @@ Electron 8.x, and has been removed in Electron 9.x. The layout zoom level limits
 are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined
 [here](https://chromium.googlesource.com/chromium/src/+/938b37a6d2886bf8335fc7db792f1eb46c65b2ae/third_party/blink/common/page/page_zoom.cc#11).
 
-### Sending non-JS objects over IPC now throws an exception
+### Behavior Changed: Sending non-JS objects over IPC now throws an exception
 
 In Electron 8.0, IPC was changed to use the Structured Clone Algorithm,
 bringing significant performance improvements. To help ease the transition, the
@@ -84,14 +90,14 @@ In Electron 9.0, the old serialization algorithm has been removed, and sending
 such non-serializable objects will now throw an "object could not be cloned"
 error.
 
-### `shell.openItem` --> `shell.openPath`
+### API Changed: `shell.openItem` is now `shell.openPath`
 
 The `shell.openItem` API has been replaced with an asynchronous `shell.openPath` API.
 You can see the original API proposal and reasoning [here](https://github.com/electron/governance/blob/master/wg-api/spec-documents/shell-openitem.md).
 
 ## Planned Breaking API Changes (8.0)
 
-### Values sent over IPC are now serialized with Structured Clone Algorithm
+### Behavior Changed: Values sent over IPC are now serialized with Structured Clone Algorithm
 
 The algorithm used to serialize objects sent over IPC (through
 `ipcRenderer.send`, `ipcRenderer.sendSync`, `WebContents.send` and related
@@ -142,7 +148,7 @@ these kinds of objects will throw a 'could not be cloned' error.
 
 [SCA]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm
 
-### `<webview>.getWebContents()`
+### Deprecated: `<webview>.getWebContents()`
 
 This API is implemented using the `remote` module, which has both performance
 and security implications. Therefore its usage should be explicit.
@@ -183,7 +189,7 @@ const { ipcRenderer } = require('electron')
 ipcRenderer.invoke('openDevTools', webview.getWebContentsId())
 ```
 
-### `webFrame.setLayoutZoomLevelLimits()`
+### Deprecated: `webFrame.setLayoutZoomLevelLimits()`
 
 Chromium has removed support for changing the layout zoom level limits, and it
 is beyond Electron's capacity to maintain it. The function will emit a warning
@@ -193,7 +199,7 @@ limits are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined
 
 ## Planned Breaking API Changes (7.0)
 
-### Node Headers URL
+### Deprecated: Atom.io Node Headers URL
 
 This is the URL specified as `disturl` in a `.npmrc` file or as the `--dist-url`
 command line flag when building native Node modules.  Both will be supported for
@@ -203,7 +209,7 @@ Deprecated: https://atom.io/download/electron
 
 Replace with: https://electronjs.org/headers
 
-### `session.clearAuthCache(options)`
+### API Changed: `session.clearAuthCache()` no longer accepts options
 
 The `session.clearAuthCache` API no longer accepts options for what to clear, and instead unconditionally clears the whole cache.
 
@@ -214,25 +220,25 @@ session.clearAuthCache({ type: 'password' })
 session.clearAuthCache()
 ```
 
-### `powerMonitor.querySystemIdleState`
+### API Changed: `powerMonitor.querySystemIdleState` is now `powerMonitor.getSystemIdleState`
 
 ```js
 // Removed in Electron 7.0
 powerMonitor.querySystemIdleState(threshold, callback)
 // Replace with synchronous API
-const idleState = getSystemIdleState(threshold)
+const idleState = powerMonitor.getSystemIdleState(threshold)
 ```
 
-### `powerMonitor.querySystemIdleTime`
+### API Changed: `powerMonitor.querySystemIdleTime` is now `powerMonitor.getSystemIdleState`
 
 ```js
 // Removed in Electron 7.0
 powerMonitor.querySystemIdleTime(callback)
 // Replace with synchronous API
-const idleTime = getSystemIdleTime()
+const idleTime = powerMonitor.getSystemIdleTime()
 ```
 
-### webFrame Isolated World APIs
+### API Changed: `webFrame.setIsolatedWorldInfo` replaces separate methods
 
 ```js
 // Removed in Electron 7.0
@@ -249,11 +255,11 @@ webFrame.setIsolatedWorldInfo(
   })
 ```
 
-### Removal of deprecated `marked` property on getBlinkMemoryInfo
+### Removed: `marked` property on `getBlinkMemoryInfo`
 
 This property was removed in Chromium 77, and as such is no longer available.
 
-### `webkitdirectory` attribute for `<input type="file"/>`
+### Behavior Changed: `webkitdirectory` attribute for `<input type="file"/>` now lists directory contents
 
 The `webkitdirectory` property on HTML file inputs allows them to select folders.
 Previous versions of Electron had an incorrect implementation where the `event.target.files`
@@ -286,9 +292,10 @@ In Electron 7, this now returns a `FileList` with a `File` object for:
 Note that `webkitdirectory` no longer exposes the path to the selected folder.
 If you require the path to the selected folder rather than the folder contents,
 see the `dialog.showOpenDialog` API ([link](https://github.com/electron/electron/blob/master/docs/api/dialog.md#dialogshowopendialogbrowserwindow-options)).
+
 ## Planned Breaking API Changes (6.0)
 
-### `win.setMenu(null)`
+### API Changed: `win.setMenu(null)` is now `win.removeMenu()`
 
 ```js
 // Deprecated
@@ -297,7 +304,7 @@ win.setMenu(null)
 win.removeMenu()
 ```
 
-### `contentTracing.getTraceBufferUsage()`
+### API Changed: `contentTracing.getTraceBufferUsage()` is now a promise
 
 ```js
 // Deprecated
@@ -310,7 +317,7 @@ contentTracing.getTraceBufferUsage().then(infoObject => {
 })
 ```
 
-### `electron.screen` in renderer process
+### API Changed: `electron.screen` in the renderer process should be accessed via `remote`
 
 ```js
 // Deprecated
@@ -319,7 +326,7 @@ require('electron').screen
 require('electron').remote.screen
 ```
 
-### `require` in sandboxed renderers
+### API Changed: `require()`ing node builtins in sandboxed renderers no longer implicitly loads the `remote` version
 
 ```js
 // Deprecated
@@ -343,25 +350,25 @@ require('path')
 require('electron').remote.require('path')
 ```
 
-### `powerMonitor.querySystemIdleState`
+### Deprecated: `powerMonitor.querySystemIdleState` replaced with `powerMonitor.getSystemIdleState`
 
 ```js
 // Deprecated
 powerMonitor.querySystemIdleState(threshold, callback)
 // Replace with synchronous API
-const idleState = getSystemIdleState(threshold)
+const idleState = powerMonitor.getSystemIdleState(threshold)
 ```
 
-### `powerMonitor.querySystemIdleTime`
+### Deprecated: `powerMonitor.querySystemIdleTime` replaced with `powerMonitor.getSystemIdleTime`
 
 ```js
 // Deprecated
 powerMonitor.querySystemIdleTime(callback)
 // Replace with synchronous API
-const idleTime = getSystemIdleTime()
+const idleTime = powerMonitor.getSystemIdleTime()
 ```
 
-### `app.enableMixedSandbox`
+### Deprecated: `app.enableMixedSandbox()` is no longer needed
 
 ```js
 // Deprecated
@@ -370,7 +377,7 @@ app.enableMixedSandbox()
 
 Mixed-sandbox mode is now enabled by default.
 
-### `Tray`
+### Deprecated: `Tray.setHighlightMode`
 
 Under macOS Catalina our former Tray implementation breaks.
 Apple's native substitute doesn't support changing the highlighting behavior.
@@ -383,7 +390,7 @@ tray.setHighlightMode(mode)
 
 ## Planned Breaking API Changes (5.0)
 
-### `new BrowserWindow({ webPreferences })`
+### Default Changed: `nodeIntegration` and `webviewTag` default to false, `contextIsolation` defaults to true
 
 The following `webPreferences` option default values are deprecated in favor of the new defaults listed below.
 
@@ -403,16 +410,16 @@ const w = new BrowserWindow({
 })
 ```
 
-### `nativeWindowOpen`
+### Behavior Changed: `nodeIntegration` in child windows opened via `nativeWindowOpen`
 
-Child windows opened with the `nativeWindowOpen` option will always have Node.js integration disabled, unless `nodeIntegrationInSubFrames` is `true.
+Child windows opened with the `nativeWindowOpen` option will always have Node.js integration disabled, unless `nodeIntegrationInSubFrames` is `true`.
 
-### Privileged Schemes Registration
+### API Changed: Registering privileged schemes must now be done before app ready
 
-Renderer process APIs `webFrame.setRegisterURLSchemeAsPrivileged` and `webFrame.registerURLSchemeAsBypassingCSP` as well as browser process API `protocol.registerStandardSchemes` have been removed.
+Renderer process APIs `webFrame.registerURLSchemeAsPrivileged` and `webFrame.registerURLSchemeAsBypassingCSP` as well as browser process API `protocol.registerStandardSchemes` have been removed.
 A new API, `protocol.registerSchemesAsPrivileged` has been added and should be used for registering custom schemes with the required privileges. Custom schemes are required to be registered before app ready.
 
-### webFrame Isolated World APIs
+### Deprecated: `webFrame.setIsolatedWorld*` replaced with `webFrame.setIsolatedWorldInfo`
 
 ```js
 // Deprecated
@@ -429,7 +436,7 @@ webFrame.setIsolatedWorldInfo(
   })
 ```
 
-## `webFrame.setSpellCheckProvider`
+### API Changed: `webFrame.setSpellCheckProvider` now takes an asynchronous callback
 The `spellCheck` callback is now asynchronous, and `autoCorrectWord` parameter has been removed.
 ```js
 // Deprecated