Fix tree item ID conflicts when resources appear in multiple tree contexts

[Copilot]

Resources appearing under both resource groups and "Source resources" nodes triggered ID conflicts in VS Code's tree view, causing expansion errors.

Root Cause

Tree item IDs were inconsistent across contexts:

• Resource group context: /accounts/{account}/tenants/{tenant}{resourceId}
• Source resources context: {msiId}/{resourceId}

Additionally, DefaultAzureResourceItem never applied its custom treeItemId to the VS Code TreeItem object.

Changes

• SourceResourceIdentityItem: Prefix child resource IDs with account/tenant context to match AzureResourceItem format

  // Before
  treeItemId: `${msi.id}/${sourceResource.id}`
  
  // After  
  treeItemId: `${getAccountAndTenantPrefix(this.subscription)}${msi.id}/${sourceResource.id}`

• DefaultAzureResourceItem: Apply custom treeItemId to TreeItem object

  getTreeItem(): vscode.TreeItem {
    const treeItem = new vscode.TreeItem(/* ... */);
    treeItem.id = this.id;  // Added
    // ...
  }

This ensures resources have consistent, unique IDs regardless of which tree path displays them.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• update.code.visualstudio.com
  • Triggering command: /usr/local/bin/node node /home/REDACTED/work/vscode-azureresourcegroups/vscode-azureresourcegroups/node_modules/.bin/vscode-test --grep SourceResourceIdentityItem tests (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>An error occurs when expanding "Source resources" node</issue_title>
<issue_description>OS: Win 11
Build Version: 20250815.1

Repro Steps:

1. Expand one resource group which has a function app -> Expand identity node -> Expand "Source resources" node.
2. Check whether succeed to expand "Source resources" node without any error.

Expect:
Succeed to expand "Source resources" node without any error.

Actual:
An error occurs.
</issue_description>

<agent_instructions>The issue here is that the tree item ids are conflicting because the same resource can be shown under the source resource node and also under a resource group. Can you investigate and fix this?</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@alexweininger Talked to @MicroFish91 offline about this and we'll investigate this week @v-ruizh This issue has been fixed on extension build 20251011.1. @v-ruizh This issue does not reproduce with the current reproduction steps. However, the same error can still be reproduced using different node expansion orders. Two reproduction scenarios are shown in the GIFs below.

</comment_new>

• Fixes An error occurs when expanding "Source resources" node #1206

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[MicroFish91]

From what I can tell, this PR fixes the new issue CTI was running into. If Copilot finds any other tree item id conflicts, we should definitely still address those though