fix: each overview tab gets opened only once

src/extension.js

@@ -77,7 +77,7 @@ const registerCommands = (context, outputChannel) => {
     [USER_COMMANDS.INSERT_SNIPPET]: insertSnippet,
     [USER_COMMANDS.VALIDATE_CI_CONFIG]: ciConfigValidator.validate,
     [USER_COMMANDS.REFRESH_SIDEBAR]: sidebar.refresh,
-    [PROGRAMMATIC_COMMANDS.SHOW_RICH_CONTENT]: webviewController.create.bind(webviewController),
+    [PROGRAMMATIC_COMMANDS.SHOW_RICH_CONTENT]: webviewController.open.bind(webviewController),
     [USER_COMMANDS.SHOW_OUTPUT]: () => outputChannel.show(),
     [USER_COMMANDS.RESOLVE_THREAD]: toggleResolved,
     [USER_COMMANDS.UNRESOLVE_THREAD]: toggleResolved,

src/webview_controller.ts

@@ -48,6 +48,8 @@ class WebviewController {
 
   isDev = false;
 
+  openedPanels: Record<string, vscode.WebviewPanel | undefined> = {};
+
   init(context: vscode.ExtensionContext, isDev: boolean) {
     this.context = context;
     this.isDev = isDev;
@@ -144,7 +146,22 @@ class WebviewController {
       : { light: lightIssueIcon, dark: darkIssueIcon };
   }
 
-  async create(issuable: RestIssuable, repositoryRoot: string) {
+  async open(issuable: RestIssuable, repositoryRoot: string) {
+    const panelKey = `${repositoryRoot}-${issuable.id}`;
+    const openedPanel = this.openedPanels[panelKey];
+    if (openedPanel) {
+      openedPanel.reveal();
+      return openedPanel;
+    }
+    const newPanel = await this.create(issuable, repositoryRoot);
+    this.openedPanels[panelKey] = newPanel;
+    newPanel.onDidDispose(() => {
+      this.openedPanels[panelKey] = undefined;
+    });
+    return newPanel;
+  }
+
+  private async create(issuable: RestIssuable, repositoryRoot: string) {
     assert(this.context);
     const panel = this.createPanel(issuable);
     const html = this.replaceResources(panel);

test/integration/webview.test.js

@@ -10,6 +10,7 @@ const { projectWithIssueDiscussions, note2 } = require('./fixtures/graphql/discu
 
 const { getServer, createJsonEndpoint } = require('./test_infrastructure/mock_server');
 const { GITLAB_URL } = require('./test_infrastructure/constants');
+const { getRepositoryRoot } = require('./test_infrastructure/helpers');
 
 const waitForMessage = (panel, type) =>
   new Promise(resolve => {
@@ -82,10 +83,7 @@ describe('GitLab webview', () => {
   beforeEach(async () => {
     server.resetHandlers();
     replacePanelEventSystem();
-    webviewPanel = await webviewController.create(
-      openIssueResponse,
-      vscode.workspace.workspaceFolders[0].uri.fsPath,
-    );
+    webviewPanel = await webviewController.open(openIssueResponse, getRepositoryRoot());
   });
 
   afterEach(async () => {
@@ -123,4 +121,17 @@ describe('GitLab webview', () => {
       assert.match(webviewPanel.webview.html, new RegExp(r, 'gm'));
     });
   });
+
+  it('reveals existing panel instead of creating a new one', async () => {
+    const revealSpy = sandbox.spy(webviewPanel, 'reveal');
+    const samePanel = await webviewController.open(openIssueResponse, getRepositoryRoot());
+    assert(revealSpy.called);
+    assert.strictEqual(samePanel, webviewPanel);
+  });
+
+  it('creates a new panel if the previous one got disposed', async () => {
+    webviewPanel.dispose();
+    const newPanel = await webviewController.open(openIssueResponse, getRepositoryRoot());
+    assert.notStrictEqual(newPanel, webviewPanel);
+  });
 });