An ActivityPub Object `likes` Collection Must be a Collection

{
  "object": {
    "help": "object with a likes property",
    "required": true,
    "rangeIncludes": [
      "https://www.w3.org/ns/activitystreams#Actor"
    ]
  }
}

{
  "input": {
    "object": {
      "help": "object with a likes property",
      "required": true,
      "rangeIncludes": [
        "https://www.w3.org/ns/activitystreams#Actor"
      ]
    }
  },
  "markdown": "---\n\ntype:\n- TestCase\ntags:\n- tests-activitypub-object\nuuid:\n- 200b9bc8-aae3-46f2-a6ab-5366042c0f6e\n\nrespec:\n  config:\n    editors:\n    - name: bengo\n      url: \"https://bengo.is\"\n      w3cid: 49026\n---\n\n# An ActivityPub Object `likes` Collection Must be a Collection\n\n## Background\n\n[ActivityPub][activitypub] says\n> Every object MAY have a likes collection.\n> &hellip;\n> The likes collection MUST be either an OrderedCollection or a Collection\n\n## About This Test\n\nThis is a Test Case describing a rule to determine whether an ActivityPub Object is in partial conformance with the following behaviors required by [ActivityPub][activitypub].\n\n* [requirement f965e989-4084-4f9d-9119-6a7ea13bcb64](https://socialweb.coop/activitypub/behaviors/f965e989-4084-4f9d-9119-6a7ea13bcb64/) - The likes collection MUST be either an OrderedCollection or a Collection\n\n### Identifier\n\nThe identifier of this test is `urn:uuid:200b9bc8-aae3-46f2-a6ab-5366042c0f6e`.\n\n## Test Subject\n\nThe subject of this test is an ActivityPub Object.\n\n## Input\n\nThis test requires the following [inputs](act-rules-input) indicating parts of the test subject:\n\n### `input.object`\n\nthe object whose `likes` property will be tested\n\n* type: binary\n* constraints\n    * should be JSON\n\n## Applicability\n\nThis test applies to each of the likes collections derived from the values of the property on `object` named `likes`.\n\n### Prerequisites\n\n* `object` is a JSON object\n* `object` JSON object has a property named `likes`\n\n### Test Targets\n\nHow to Derive Test Targets from Input\n\n* let `targets` be a set\n* let `likesValues` be the result of\n    * if `object.likes` is an Array, return it\n    * else return an Array whose only item is the value of `object.likes`\n* for each item in `likesValues`\n    * if item is a string\n        * let itemFetched be the result of interpreting the string as an ActivityPub Object Identifier and fetching the corresponding ActivityPub Object.\n        * add itemFetched to `targets`\n    * else add item to `targets`\n* return `targets`\n\n## Expectations\n\nFor every target `target`\n\n* `target` is a JSON object\n* `target` has a property named `type`\n* the value of the `target`'s `type` property must be one of\n    * an array containing the string \"Collection\"\n    * an array containing the string \"OrderedCollection\"\n    * the string \"Collection\"\n    * the string \"OrderedCollection\"\n\n## Test Cases\n\nWhat follows are some specific cases of applything this test rule.\n\n### Passed Example 1\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": {\n      \"type\": \"Collection\"\n    }\n  }\n  ```\n\ntest targets\n\n* ```json\n  {\n    \"type\": \"Collection\"\n  }\n  ```\n\n    * outcome: `passed`\n\n### Passed Example 2\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": {\n      \"type\": \"OrderedCollection\"\n    }\n  }\n  ```\n\ntest targets\n\n* ```json\n  {\n    \"type\": \"OrderedCollection\"\n  }\n  ```\n\n    * outcome: `passed`\n\n### Passed Example 3\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": {\n      \"type\": [\"FancyCollection\", \"OrderedCollection\"]\n    }\n  }\n  ```\n\ntest targets\n\n* ```json\n  {\n    \"likes\": {\n      \"type\": [\"FancyCollection\", \"OrderedCollection\"]\n    }\n  }\n  ```\n\n    * outcome: `passed`\n        * rationale: `\"FancyCollection\"` is not well-defined here, but this object still passes the test because at least one of the `type` property values is `OrderedCollection` and thus satisfies the requirement as interpreted.\n\n### Failed Example 1 - Likes is a number\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": 1\n  }\n  ```\n\ntest targets\n\n* ```json\n  1\n  ```\n\n    * outcome: `failed`\n\n### Failed Example 2 - Likes is an empty object\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": {}\n  }\n  ```\n\ntest targets\n\n* ```json\n  {}\n  ```\n\n    * outcome: `failed`\n\n### Failed Example 3 - Likes object type is array including only `\"Link\"`\n\ninputs\n\n* `object`:\n\n  ```json\n  {\n    \"likes\": {\n      \"type\": [\"Link\"]\n    }\n  }\n  ```\n\ntest targets\n\n* ```json\n  {\n    \"type\": [\"Link\"]\n  }\n  ```\n\n    * outcome: `failed`\n\n### Inapplicable Example 1\n\ninputs\n\n* `object`:\n\n  ```json\n  1\n  ```\n\nresult\n\n* outcome: `inapplicable`\n\n### Inapplicable Example 2 - object has no likes property\n\ninputs\n\n* `object`:\n\n  ```json\n  { \"foo\": \"bar\" }\n  ```\n\nresult\n\n* outcome: `inapplicable`\n\n### Inapplicable Example 3 - object is html\n\ninputs\n\n* `object`:\n\n  ```html\n  <!doctype html>hi\n  ```\n\nresult\n\n* outcome: `inapplicable`\n\n## Glossary [<sup>?</sup>](https://www.w3.org/TR/act-rules-format/#glossary)\n\n### `outcome`\n\nAn outcome is a conclusion that comes from evaluating a test on a test subject. An outcome can be one of the three following types:\n\n* `inapplicable`: No part of the test subject matches the applicability\n* `passed`: A test target meets all expectations\n* `failed`: A test target does not meet all expectations\n\n## Requirements Mapping [<sup>?</sup>](https://www.w3.org/TR/act-rules-format/#accessibility-requirements-mapping)\n\n* [ActivityPub requirement f965e989-4084-4f9d-9119-6a7ea13bcb64](https://socialweb.coop/activitypub/behaviors/f965e989-4084-4f9d-9119-6a7ea13bcb64/) - The likes collection MUST be either an OrderedCollection or a Collection\n    * Required for Conformance to [ActivityPub][activitypub]\n    * Outcome Mapping\n        * when every test target has outcome `passed`, the requirement is satisfied by the test subject\n        * when any test target has outcome `failed`, the requirement is not satisfied by the test subject\n        * when any test target has outcome `inapplicable`, further testing is needed to determine requirement satisfaction\n\n## Issues [<sup>?</sup>](https://www.w3.org/TR/act-rules-format/issues-list)\n\n## Change Log\n\n* 2023-12-06T06:48:14.689Z: init\n* 2023-12-18T04:33:22.670Z: add more example cases that were useful for maximizing implementation code coverage\n\n[activitypub]: https://www.w3.org/TR/activitypub/\n",
  "name": "An ActivityPub Object `likes` Collection Must be a Collection",
  "description": "tests whether an ActivityPub Object has a likes collection with an appropriate Collection type",
  "slug": "likes-collection-must-be-a-collection",
  "inapplicableCases": [
    {
      "name": "inapplicable example 1",
      "input": {
        "object": "1"
      },
      "result": {
        "outcome": "inapplicable"
      }
    },
    {
      "name": "inapplicble example 2 - object has no likes property",
      "input": {
        "object": "\n      { \"foo\": \"bar\" }\n      "
      },
      "result": {
        "outcome": "inapplicable"
      }
    },
    {
      "name": "inapplicable example 3 - html object",
      "input": {
        "object": "<!doctype html>hi"
      },
      "result": {
        "outcome": "inapplicable"
      }
    }
  ],
  "passedCases": [
    {
      "name": "passed example 1",
      "input": {
        "object": "\n        {\n          \"likes\": {\n            \"type\": \"Collection\"\n          }\n        }\n      "
      },
      "result": {
        "outcome": "passed"
      }
    },
    {
      "name": "passed example 2",
      "input": {
        "object": "\n      {\n        \"likes\": {\n          \"type\": [\"FancyCollection\", \"OrderedCollection\"]\n        }\n      }\n      "
      },
      "result": {
        "outcome": "passed"
      }
    }
  ],
  "failedCases": [
    {
      "name": "failed example 1",
      "input": {
        "object": "\n        {\n          \"likes\": 1\n        }\n      "
      },
      "result": {
        "outcome": "failed"
      }
    },
    {
      "name": "failed example 2",
      "input": {
        "object": "\n        {\n          \"likes\": {}\n        }\n      "
      },
      "result": {
        "outcome": "failed"
      }
    },
    {
      "name": "failed example 3",
      "input": {
        "object": "\n        {\n          \"likes\": {\n            \"type\": [\"Link\"]\n          }\n        }\n      "
      },
      "result": {
        "outcome": "failed"
      }
    }
  ],
  "uuid": "200b9bc8-aae3-46f2-a6ab-5366042c0f6e",
  "isPartOf": [
    "https://socialweb.coop/activitypub/test-cases/"
  ],
  "requirementReference": [
    {
      "id": "urn:uuid:f965e989-4084-4f9d-9119-6a7ea13bcb64",
      "url": "https://socialweb.coop/activitypub/behaviors/f965e989-4084-4f9d-9119-6a7ea13bcb64/"
    }
  ]
}