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valid-importmap

Validate the body of <script type="importmap"> elements against HTML Living Standard § Parse an import map string. type attribute matching is ASCII case-insensitive, matching how user agents look up the script's effective MIME type.

Split out of the former script-content rule, alongside valid-speculation-rules for type="speculationrules".

The rule reports the following issues for inline import maps:

  • The element body is empty or whitespace-only
  • The body cannot be parsed as JSON
  • The top-level value is not a JSON object
  • The top-level value contains a key other than imports, scopes, or integrity
  • imports or scopes is not a JSON object
  • A specifier map (imports, or a value inside scopes) contains an empty key
  • A specifier map address (the value side) is not a string
  • A specifier map address is not a URL-like specifier (does not start with /, ./, ../, and is not an absolute URL)
  • A specifier key ends with / but its address does not
  • integrity is not a JSON object
  • An integrity key is not a URL-like specifier
  • An integrity value is not a string

❌ Examples of incorrect code for this rule

<script type="importmap"></script>
<script type="importmap">
  {
    "forbidden": {}
  }
</script>
<script type="importmap">
  {
    "imports": {
      "dir/": "/path/to/dir"
    }
  }
</script>

✅ Examples of correct code for this rule

<script type="importmap">
  {
    "imports": {
      "app": "/path/to/app.js",
      "dir/": "/path/to/dir/"
    },
    "scopes": {
      "/scope/": {
        "x": "./y.js"
      }
    }
  }
</script>

Interface​

{
  "valid-importmap": boolean
}

Validate the body of <script type="importmap"> elements against the import map spec.

Default Severity​

error