Fix infinite callbacks in Azure Resource Explorer (#3780)

extensions/azurecore/src/azureResource/tree/accountTreeNode.ts

@@ -90,12 +90,9 @@ export class AzureResourceAccountTreeNode extends AzureResourceContainerTreeNode
 			}
 		} catch (error) {
 			if (error instanceof AzureResourceCredentialError) {
-				this.appContext.apiWrapper.showErrorMessage(error.message);
-
 				this.appContext.apiWrapper.executeCommand('azure.resource.signin');
-			} else {
-				return [AzureResourceMessageTreeNode.create(AzureResourceErrorMessageUtil.getErrorMessage(error), this)];
 			}
+			return [AzureResourceMessageTreeNode.create(AzureResourceErrorMessageUtil.getErrorMessage(error), this)];
 		}
 	}
 

extensions/azurecore/src/azureResource/tree/treeProvider.ts

@@ -32,7 +32,7 @@ export class AzureResourceTreeProvider implements TreeDataProvider<TreeNode>, IA
 			return element.getChildren(true);
 		}
 
-		if (!this.isSystemInitialized) {
+		if (!this.isSystemInitialized && !this._loadingTimer) {
 			this._loadingTimer = setInterval(async () => {
 				try {
 					// Call sqlops.accounts.getAllAccounts() to determine whether the system has been initialized.

extensions/azurecore/src/azureResource/utils.ts

@@ -41,3 +41,56 @@ export function generateGuid(): string {
     return oct.substr(0, 8) + '-' + oct.substr(9, 4) + '-4' + oct.substr(13, 3) + '-' + clockSequenceHi + oct.substr(16, 3) + '-' + oct.substr(19, 12);
     /* tslint:enable:no-bitwise */
 }
+
+export function equals(one: any, other: any): boolean {
+    if (one === other) {
+        return true;
+    }
+    if (one === null || one === undefined || other === null || other === undefined) {
+        return false;
+    }
+    if (typeof one !== typeof other) {
+        return false;
+    }
+    if (typeof one !== 'object') {
+        return false;
+    }
+    if ((Array.isArray(one)) !== (Array.isArray(other))) {
+        return false;
+    }
+
+    let i: number;
+    let key: string;
+
+    if (Array.isArray(one)) {
+        if (one.length !== other.length) {
+            return false;
+        }
+        for (i = 0; i < one.length; i++) {
+            if (!equals(one[i], other[i])) {
+                return false;
+            }
+        }
+    } else {
+        const oneKeys: string[] = [];
+
+        for (key in one) {
+            oneKeys.push(key);
+        }
+        oneKeys.sort();
+        const otherKeys: string[] = [];
+        for (key in other) {
+            otherKeys.push(key);
+        }
+        otherKeys.sort();
+        if (!equals(oneKeys, otherKeys)) {
+            return false;
+        }
+        for (i = 0; i < oneKeys.length; i++) {
+            if (!equals(one[oneKeys[i]], other[oneKeys[i]])) {
+                return false;
+            }
+        }
+    }
+    return true;
+}

extensions/azurecore/src/controllers/azureResourceController.ts

@@ -25,6 +25,7 @@ import { AzureResourceTenantService } from '../azureResource/services/tenantServ
 
 import { registerAzureResourceDatabaseServerCommands } from '../azureResource/providers/databaseServer/commands';
 import { registerAzureResourceDatabaseCommands } from '../azureResource/providers/database/commands';
+import { equals } from '../azureResource/utils';
 
 export default class AzureResourceController extends ControllerBase {
 	public activate(): Promise<boolean> {
@@ -37,7 +38,16 @@ export default class AzureResourceController extends ControllerBase {
 		const azureResourceTree = new AzureResourceTreeProvider(this.appContext);
 		this.extensionContext.subscriptions.push(this.apiWrapper.registerTreeDataProvider('azureResourceExplorer', azureResourceTree));
 
-		this.appContext.getService<IAzureResourceAccountService>(AzureResourceServiceNames.accountService).onDidChangeAccounts((e: DidChangeAccountsParams) => { azureResourceTree.notifyNodeChanged(undefined); });
+		let previousAccounts = undefined;
+		this.appContext.getService<IAzureResourceAccountService>(AzureResourceServiceNames.accountService).onDidChangeAccounts((e: DidChangeAccountsParams) => {
+			// the onDidChangeAccounts event will trigger in many cases where the accounts didn't actually change
+			// the notifyNodeChanged event triggers a refresh which triggers a getChildren which can trigger this callback
+			// this below check short-circuits the infinite callback loop
+			if (!equals(e.accounts, previousAccounts)) {
+				azureResourceTree.notifyNodeChanged(undefined);
+			}
+			previousAccounts = e.accounts;
+		});
 
 		registerAzureResourceCommands(this.appContext, azureResourceTree);