Fix select preset/kit commands to return strings for task variable substitution

[Copilot]

This change addresses item #4239

This changes visible behavior of preset and kit selection commands when used as ${command:...} variables

The following changes are proposed:

• Change selectConfigurePreset, selectBuildPreset, selectTestPreset, selectPackagePreset, selectWorkflowPreset, and selectKit in ExtensionManager to return Promise<string> (selected name) instead of Promise<boolean>
• Return empty string on cancellation/failure, selected preset/kit name on success
• Add CHANGELOG entry for the fix

The purpose of this change

Using ${command:cmake.selectConfigurePreset} in tasks.json fails with:

Cannot substitute command variable 'cmake.selectConfigurePreset' because command did not return a result of type string.

VS Code's command variable substitution requires a string return value. These commands returned boolean.

Other Notes/Information

The change is backward-compatible: all internal callers use truthiness checks (!didChoosePreset), and empty string is falsy / non-empty string is truthy — identical semantics to false/true.

// tasks.json — now works without error
{
    "label": "set active config",
    "command": "${command:cmake.selectConfigurePreset}"
}

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Using ${command:cmake.selectConfigurePreset} in tasks.json pops up error when selecting already active configuration</issue_title>
<issue_description>### Brief Issue Summary

Hi,

I have a vscode task that I use to change the current configuration preset:

{
    "label": "set active config",
    "group": "build",
    "command": "${command:cmake.selectConfigurePreset}"
}

I can toggle without issues between configurations Release, Debug. The issue arises when I select the already active configuration, then I get this error:
Cannot substitute command variable 'cmake.selectConfigurePreset' because command did not return a result of type string.

How to reproduce

1. Run the task, select "X" configuration
2. Run the task again, select the same "X" configuration

CMake Tools Diagnostics

{
  "os": "linux",
  "vscodeVersion": "1.95.3",
  "cmtVersion": "1.19.52",
  "configurations": [
    {
      "folder": "/opt/my-project",
      "cmakeVersion": "3.27.0",
      "configured": true,
      "generator": "Unix Makefiles",
      "usesPresets": true,
      "compilers": {
        "C": "/usr/bin/gcc",
        "CXX": "/usr/bin/g++"
      }
    }
  ],
  "cpptoolsIntegration": {
    "isReady": true,
    "hasCodeModel": true,
    "activeBuildType": "Debug",
    "buildTypesSeen": [
      "Debug"
    ],
    "requests": [],
    "responses": [],
    "partialMatches": [],
    "targetCount": 34,
    "executablesCount": 3,
    "librariesCount": 3,
    "targets": []
  },
  "settings": [
    {
      "communicationMode": "automatic",
      "useCMakePresets": "auto",
      "configureOnOpen": false
    }
  ]
}

Debug Log

Additional Information

No response</issue_description>

<agent_instructions>fix this issue in a pr and cite issue 4239 in the change log</agent_instructions>

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

• Fixes Using ${command:cmake.selectConfigurePreset} in tasks.json pops up error when selecting already active configuration #4239

---

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[Omotola]

validated locally:

Before fix - task doesn't execute, it gives an error:

After fix - task is executing as expected:

[hanniavalera]

@copilot fix the CHANGELOG.md as it was not rebased/merged properly against main, do not change the PR description

[Copilot]

@copilot fix the CHANGELOG.md as it was not rebased/merged properly against main, do not change the PR description

Resolved the merge conflict markers in CHANGELOG.md — both entries (ours for #4239 and the #4343 fix from main) are now properly included. See commit d1f19b6.