©️ socialweb.coop

Background

ActivityPub § 5.1 Outbox:

The outbox is discovered through the outbox property of an actor's profile. The outbox MUST be an OrderedCollection.

About this Test

This is a Test Case describing a rule to determine whether an ActivityPub object has an outbox property that meets this requirement to 'be an OrderedCollection', meeting requirement 3b925cdf-89fe-4f51-b41f-26df23f58e0c

Identifier

The identifier of this test is urn:uuid:4af549f4-3797-4d99-a151-67c3d8feaa46 .

Test Subject

The subject of this test is any data claiming to conform to the specification of an ActivityPub Actor Object.

This test is not inherently applicable to an ActivityPub Server. An ActivityPub Server serves 0 or more Actor Objects. An ActivityPub Server for a big community might serve hundreds of ActivityPub Actor Objects. An ActivityPub Server for a single human may serve only that person's ActivityPub Actor Object.

This test is not inherently applicable to a URL of an Actor Object. The URL is not the same as the Actor Object. The URL may resolve to different Actor Objects in different contexts.

Inputs

This test requires the following inputs:

1. object - the object whose outbox property will be tested

   • type: binary
   • constraints
     • will be interpreted as JSON

2. time - amount of time allowed to run test. This is meant to configure the limit for how long this test will wait for network requests.

   • required: yes
   • example: T0.0021S
   • type: binary
   • constraints
     • MUST be an RFC3339 dur-time

Applicability

This test applies to outbox objects linked to from the object input. Usually an actor will have one outbox, but there may be multiple.

This test does not apply to objects with more than one outbox . If the input object has an outbox property whose value is an array of length >= 2, outcome is inapplicable. (See issue #5102 below to track expanding the applicability)

If object is not parseable as JSON to a JSON object, outcome is inapplicable.

If object is a JSON object, but it does not contain a property named outbox, outcome is inapplicable. The rationale is that there is already a test acaacb5f-8f7e-4f28-8d81-c7955070a767 that can be used to determine if input object has an outbox property at all.

Test Targets

• outbox - the value of the outbox property in the input object object
  • since the object object must be JSON for this test's applicability, the value of JSON.parse(actor).outbox must also be JSON
  • how to derive outbox from inputs
    1. let outboxValue be
       • if inputs.actor.outbox is a JSON string, outboxValue is that string
       • if inputs.actor.outbox is a JSON object, outboxValue is that object
       • if inputs.actor.outbox is an Array of length 1, outboxValue is the item in that array
       • if inputs.actor.outbox is an Array of length greater than 1, the test outcome is inapplicable (covered in 'Applicability' above)
         • see issue #5102 below to track expanding the applicability to support outbox property values that are arrays with length greater than 1
    2. let outboxObject be
       • if outboxValue is a JSON object, outboxObject is that object
       • if outboxValue is a JSON string, outboxObject is the result of interpreting that string as an ActivityPub Object Identifier and fetching the corresponding ActivityPub Object (e.g. GET https://...).
    3. test target outbox is outboxObject

Expectations

1. outbox is a JSON object
2. outbox has a property named `type``
3. the values of the outbox's type property must contain "OrderedCollection", as determined by
   • if value of outbox's type property is a string, it MUST be "OrderedCollection"
   • if value of outbox's type property is an Array, it MUST contain an entry identical to "OrderedCollection"

Assumptions

Interpreting "MUST be an OrderedCollection"

Revisiting the background from above, ActivityPub says

The outbox is discovered through the outbox property of an actor's profile. The outbox MUST be an OrderedCollection.

"MUST be an OrderedCollection" is open to some interpretation here.

This test chose to interpret 'be an' to include 'indicate its type as'. The rationale is that it's easy to check and easy to implement.

Test Cases

object has simple valid outbox

inputs

• object

  {
    "outbox": {
      "id": "http://example.org/blog/",
      "type": "OrderedCollection",
      "name": "Martin's Blog"
    }
  }
  

  • note: this OrderedCollection is from Example 5 in activitystreams-core

test targets

• outbox

  • value:

    {
      "id": "http://example.org/blog/",
      "type": "OrderedCollection",
      "name": "Martin's Blog"
    }
    

  • outcome: passed

object outbox is null

inputs

• object

  {
    "outbox": null
  }
  

test targets

• outbox

  • value:

    null
    

  • outcome: failed

    • rationale: outbox is obviously not an OrderedCollection

object outbox type array contains Person

inputs

• object

  {
    "outbox": {
      "type": ["Person"]
    }
  }
  

test targets

• outbox

  • value:

    {
      "type": ["Person"]
    }
    

  • outcome: failed

    • rationale: outbox type is not OrderedCollection

inapplicable because outbox has many values

inputs

• object

  {
    "outbox": ["https://example.com", "https://example.com"]
  }
  

test targest

• outbox

  • value:

    ["https://example.com", "https://example.com"]
    

  • outcome: inapplicable

    • rationale: outbox values that are arrays of length greater than 1 are not covered by this test's applicability. See issue #5102 below to track expanding the applicability

result

• outcome: inapplicable

object is empty object

inputs

• object

  {}
  

result

• outcome: inapplicable

object is not JSON

inputs

• object

  \0x123abc_intentionallyNotJson
  

result

• outcome: inapplicable

Glossary

outcome

An outcome is a conclusion that comes from evaluating a test on a test subject. An outcome can be one of the three following types:

• inapplicable: No part of the test subject matches the applicability
• passed: A test target meets all expectations
• failed: A test target does not meet all expectations

Requirements Mapping

• ActivityPub Requirement 003a3be2-fb58-4812-a3a3-795067254327 - The outbox MUST be an OrderedCollection
  • Required for Conformance to ActivityPub
  • Outcome Mapping
    • when test target outbox has outcome passed, requirement is satisfied
    • when test target outbox has outcome failed, requirement is not satisfied
    • when test target outbox has outcome inapplicable, further testing is needed to determine requirement satisfaction

Change Log

• 2023-11-22T05:12:58.454Z - first draft, heavily copy from ../inbox-must-be-an-orderedcollection/inbox-must-be-an-orderedcollection.md
• 2023-12-29T22:46:03.806Z - reformat test cases to give each one its own heading

Issues

Required

• add a test case where outbox is a URI that is resolved to an OrderedCollection an the outcome is "passed"
  • decide what the URL will be. Does it need to publicly resolve for a long time? maybe https://socialweb.coop/actors/empty-outbox.json
    • if that's not feasible, the test case could have the outbox test target stubbed out so at least that part could be checked

Nice to Have

• #01d2: resolving outbox url should use inputs.time and timeout
• #5102: expand applicability to handle cases where there are multiple outboxes