decolint on GitHub

unused-template-option

disallow a Template option that no file in the Template references

Category
style
Applies to
template
Platforms
all

Why

An option only takes effect where a file substitutes it as “${templateOption:name}”. One that nothing references is still presented to the user when the Template is applied, so it asks a question whose answer changes nothing — usually a leftover from a removed file or a renamed reference.

Bad

devcontainer-template.json

{
  "id": "dotnet",
  "version": "1.0.0",
  "name": "C# (.NET)",
  "options": {
    "imageVariant": {
      "type": "string",
      "proposals": ["8.0", "9.0"],
      "default": "9.0"
    }
  }
}

.devcontainer/devcontainer.json

{
  "image": "mcr.microsoft.com/devcontainers/dotnet:9.0"
}

Good

devcontainer-template.json

{
  "id": "dotnet",
  "version": "1.0.0",
  "name": "C# (.NET)",
  "options": {
    "imageVariant": {
      "type": "string",
      "proposals": ["8.0", "9.0"],
      "default": "9.0"
    }
  }
}

.devcontainer/devcontainer.json

{
  "image": "mcr.microsoft.com/devcontainers/dotnet:${templateOption:imageVariant}"
}

References