Show DevTools backend and frontend versions in UI (facebook#23399)

This information can help with bug investigation for renderers (like React Native) that embed the DevTools backend into their source (separately from the DevTools frontend, which gets run by the user).

If the DevTools backend is too old to report a version, or if the version reported is the same as the frontend (as will be the case with the browser extension) then only a single version string will be shown, as before. If a different version is reported, then both will be shown separately.

packages/react-devtools-shared/src/backend/agent.js

@@ -185,6 +185,7 @@ export default class Agent extends EventEmitter<{|
     bridge.addListener('clearWarningsForFiberID', this.clearWarningsForFiberID);
     bridge.addListener('copyElementPath', this.copyElementPath);
     bridge.addListener('deletePath', this.deletePath);
+    bridge.addListener('getBackendVersion', this.getBackendVersion);
     bridge.addListener('getBridgeProtocol', this.getBridgeProtocol);
     bridge.addListener('getProfilingData', this.getProfilingData);
     bridge.addListener('getProfilingStatus', this.getProfilingStatus);
@@ -225,7 +226,12 @@ export default class Agent extends EventEmitter<{|
       bridge.send('profilingStatus', true);
     }
 
-    // Send the Bridge protocol after initialization in case the frontend has already requested it.
+    // Send the Bridge protocol and backend versions, after initialization, in case the frontend has already requested it.
+    // The Store may be instantiated beore the agent.
+    const version = process.env.DEVTOOLS_VERSION;
+    if (version) {
+      this._bridge.send('backendVersion', version);
+    }
     this._bridge.send('bridgeProtocol', currentBridgeProtocol);
 
     // Notify the frontend if the backend supports the Storage API (e.g. localStorage).
@@ -322,6 +328,13 @@ export default class Agent extends EventEmitter<{|
     return null;
   }
 
+  getBackendVersion = () => {
+    const version = process.env.DEVTOOLS_VERSION;
+    if (version) {
+      this._bridge.send('backendVersion', version);
+    }
+  };
+
   getBridgeProtocol = () => {
     this._bridge.send('bridgeProtocol', currentBridgeProtocol);
   };

packages/react-devtools-shared/src/bridge.js

@@ -185,6 +185,7 @@ type SavedPreferencesParams = {|
 |};
 
 export type BackendEvents = {|
+  backendVersion: [string],
   bridgeProtocol: [BridgeProtocol],
   extensionBackendInitialized: [],
   fastRefreshScheduled: [],
@@ -219,6 +220,7 @@ type FrontendEvents = {|
   clearWarningsForFiberID: [ElementAndRendererID],
   copyElementPath: [CopyElementPathParams],
   deletePath: [DeletePath],
+  getBackendVersion: [],
   getBridgeProtocol: [],
   getOwnersList: [ElementAndRendererID],
   getProfilingData: [{|rendererID: RendererID|}],

packages/react-devtools-shared/src/devtools/store.js

@@ -85,6 +85,7 @@ export type Capabilities = {|
  * ContextProviders can subscribe to the Store for specific things they want to provide.
  */
 export default class Store extends EventEmitter<{|
+  backendVersion: [],
   collapseNodesByDefault: [],
   componentFilters: [],
   error: [Error],
@@ -98,6 +99,10 @@ export default class Store extends EventEmitter<{|
   unsupportedBridgeProtocolDetected: [],
   unsupportedRendererVersionDetected: [],
 |}> {
+  // If the backend version is new enough to report its (NPM) version, this is it.
+  // This version may be displayed by the frontend for debugging purposes.
+  _backendVersion: string | null = null;
+
   _bridge: FrontendBridge;
 
   // Computed whenever _errorsAndWarnings Map changes.
@@ -264,6 +269,9 @@ export default class Store extends EventEmitter<{|
       bridge.addListener('bridgeProtocol', this.onBridgeProtocol);
       bridge.send('getBridgeProtocol');
     }
+
+    bridge.addListener('backendVersion', this.onBridgeBackendVersion);
+    bridge.send('getBackendVersion');
   }
 
   // This is only used in tests to avoid memory leaks.
@@ -301,6 +309,10 @@ export default class Store extends EventEmitter<{|
     }
   }
 
+  get backendVersion(): string | null {
+    return this._backendVersion;
+  }
+
   get collapseNodesByDefault(): boolean {
     return this._collapseNodesByDefault;
   }
@@ -1333,6 +1345,7 @@ export default class Store extends EventEmitter<{|
       'unsupportedRendererVersion',
       this.onBridgeUnsupportedRendererVersion,
     );
+    bridge.removeListener('backendVersion', this.onBridgeBackendVersion);
     bridge.removeListener('bridgeProtocol', this.onBridgeProtocol);
 
     if (this._onBridgeProtocolTimeoutID !== null) {
@@ -1359,6 +1372,11 @@ export default class Store extends EventEmitter<{|
     this.emit('unsupportedRendererVersionDetected');
   };
 
+  onBridgeBackendVersion = (backendVersion: string) => {
+    this._backendVersion = backendVersion;
+    this.emit('backendVersion');
+  };
+
   onBridgeProtocol = (bridgeProtocol: BridgeProtocol) => {
     if (this._onBridgeProtocolTimeoutID !== null) {
       clearTimeout(this._onBridgeProtocolTimeoutID);

packages/react-devtools-shared/src/devtools/views/Settings/GeneralSettings.js

@@ -8,13 +8,26 @@
  */
 
 import * as React from 'react';
-import {useContext} from 'react';
+import {useContext, useMemo} from 'react';
 import {SettingsContext} from './SettingsContext';
 import {StoreContext} from '../context';
 import {CHANGE_LOG_URL} from 'react-devtools-shared/src/constants';
 
 import styles from './SettingsShared.css';
 
+function getChangeLogUrl(version: ?string): string | null {
+  if (!version) {
+    return null;
+  }
+
+  // Version numbers are in the format of: <major>.<minor>.<patch>-<sha>
+  // e.g. "4.23.0-f0dd459e0"
+  // GitHub CHANGELOG headers are in the format of: <major>.<minor>.<patch>
+  // but the "." are stripped from anchor tags, becomming: <major><minor><patch>
+  const versionAnchor = version.replace(/^(\d+)\.(\d+)\.(\d+).*/, '$1$2$3');
+  return `${CHANGE_LOG_URL}#${versionAnchor}`;
+}
+
 export default function GeneralSettings(_: {||}) {
   const {
     displayDensity,
@@ -25,7 +38,11 @@ export default function GeneralSettings(_: {||}) {
     traceUpdatesEnabled,
   } = useContext(SettingsContext);
 
-  const {supportsTraceUpdates} = useContext(StoreContext);
+  const {backendVersion, supportsTraceUpdates} = useContext(StoreContext);
+  const frontendVersion = process.env.DEVTOOLS_VERSION;
+
+  const showBackendVersion =
+    backendVersion && backendVersion !== frontendVersion;
 
   return (
     <div className={styles.Settings}>
@@ -70,15 +87,51 @@ export default function GeneralSettings(_: {||}) {
       )}
 
       <div className={styles.ReleaseNotes}>
+        {showBackendVersion && (
+          <div>
+            <ul className={styles.VersionsList}>
+              <li>
+                <Version
+                  label="DevTools backend version:"
+                  version={backendVersion}
+                />
+              </li>
+              <li>
+                <Version
+                  label="DevTools frontend version:"
+                  version={frontendVersion}
+                />
+              </li>
+            </ul>
+          </div>
+        )}
+        {!showBackendVersion && (
+          <Version label="DevTools version:" version={frontendVersion} />
+        )}
+      </div>
+    </div>
+  );
+}
+
+function Version({label, version}: {|label: string, version: ?string|}) {
+  const changelogLink = useMemo(() => {
+    return getChangeLogUrl(version);
+  }, [version]);
+
+  if (version == null) {
+    return null;
+  } else {
+    return (
+      <>
+        {label}{' '}
         <a
           className={styles.ReleaseNotesLink}
           target="_blank"
           rel="noopener noreferrer"
-          href={CHANGE_LOG_URL}>
-          View release notes
-        </a>{' '}
-        for DevTools version {process.env.DEVTOOLS_VERSION}
-      </div>
-    </div>
-  );
+          href={changelogLink}>
+          {version}
+        </a>
+      </>
+    );
+  }
 }

packages/react-devtools-shared/src/devtools/views/Settings/SettingsShared.css

@@ -149,4 +149,10 @@
 
 .Warning {
   color: var(--color-error-text);
+}
+
+.VersionsList {
+  list-style: none;
+  padding: 0;
+  margin: 0;
 }

packages/react-devtools-shell/src/app/index.js

@@ -10,7 +10,6 @@ import Iframe from './Iframe';
 import EditableProps from './EditableProps';
 import ElementTypes from './ElementTypes';
 import Hydration from './Hydration';
-import InlineWarnings from './InlineWarnings';
 import InspectableElements from './InspectableElements';
 import ReactNativeWeb from './ReactNativeWeb';
 import ToDoList from './ToDoList';
@@ -83,7 +82,6 @@ function mountTestApp() {
   mountApp(Hydration);
   mountApp(ElementTypes);
   mountApp(EditableProps);
-  mountApp(InlineWarnings);
   mountApp(ReactNativeWeb);
   mountApp(Toggle);
   mountApp(ErrorBoundaries);