no-repeated-path-info

Id

@azure-tools/typespec-azure-resource-manager/no-repeated-path-info

ARM PUT request bodies must not repeat path or query parameters in the resource properties bag.

ARM PUT request bodies should not repeat information already supplied in path or query parameters. Keep resource identity in the request URI and resource-specific data in the resource’s properties bag, so callers do not have to supply potentially conflicting values twice.

This rule complements arm-resource-duplicate-property, which compares properties-bag members with envelope property names on ARM resource models, independently of operations. For example, an envelope name with @key("widgetName") makes properties.widgetName a URI duplication only. Conversely, properties.identity duplicates an envelope identity only under the envelope rule when no URI parameter is named identity. Both rules can report a member when its name matches both an envelope property and a URI parameter.

Impact

• Area: API, SDK

Repeating URI information in resource properties creates redundant SDK inputs and ambiguity when the request URI and payload disagree.

❌ Incorrect

The standard ARM create-or-replace operation carries widgetName in the URI. With ArmResourceCreateOrReplaceSync<Widget>, repeating that key name in WidgetProperties triggers this rule. These excerpts omit unchanged provider and operation declarations.

model Widget is TrackedResource<WidgetProperties> {
  @key("widgetName")
  @segment("widgets")
  @path
  name: string;
}

model WidgetProperties {
  widgetName?: string;
  description?: string;
}

✅ Correct

Keep the resource key and operation template unchanged; remove only the redundant properties-bag member.

model WidgetProperties {
  description?: string;
}

Suppression

Prefer removing the redundant properties-bag member. If a published API must retain the duplication for compatibility and an ARM reviewer has approved the exception, suppress the warning on that member with a specific justification:

model WidgetProperties {
  #suppress "@azure-tools/typespec-azure-resource-manager/no-repeated-path-info" "Retained for compatibility with the approved published API."
  widgetName?: string;
}

LintDiff Equivalent

This rule corresponds to RepeatedPathInfo and ARM guideline RPC-Put-V1-05. Like the Swagger validator, it compares JSON property names, including JSON name overrides, with path and query parameter names. It checks native TypeSpec operations rather than an emitted single-version schema.