Prerequisites

Set up a new field in issue custom fields with the following settings:

• Type: User
• Name: Assignees
• Allow Multiple: true
• Allow Empty Value: true
• Name of Empty Value: Not assigned
• Available choices: all users
• Default value: no default value
• Include when issue is opened: true
• Applicable projects: all

Create 2 issues, say with id 1 and 2.

Assign issue 1 to one user Assign issue 2 to two different users

Steps to reproduce

• curl -X GET -H 'Authorization: Basic XXX' 'https://code.onedev.io/~api/issues/1/fields'
• curl -X GET -H 'Authorization: Basic XXX' 'https://code.onedev.io/~api/issues/2/fields'

Expected behavior:

for 1:

{
  "Type": "Task",
  "When": null,
  "Priority": "Normal",
  "Blocked by": null,
  "Service": "Services",
  "Assignees": [ "senderman" ],
  "Resolution": null
}

for 2:

{
  "Type": "Task",
  "When": null,
  "Priority": "Normal",
  "Blocked by": null,
  "Service": "DevOps",
  "Assignees": [
    "senderman",
    "vezono"
  ],
  "Resolution": null
}

Actual behavior:

for 1:

{
  "Type": "Task",
  "When": null,
  "Priority": "Normal",
  "Blocked by": null,
  "Service": "Services",
  "Assignees": "senderman",
  "Resolution": null
}

for 2, the same as in the expected behavior.

So the issue here is that a field than can contain multiple values can be returned both as scalar and array, which makes it difficult for parsing in languages which require strict types such as java.