Slack service API returns "1" and "0" for boolean properties.

Summary

Slack service API returns "1" and "0" for boolean properties notify_only_broken_pipelines and notify_only_default_branch, but should return true or false.

Steps to reproduce

1. Export environment variables for convenience

    export GITLAB_URL="https://gitlab.com/api/v4"
    export GITLAB_TOKEN="put-token-here"
    

2. Create a new project

    curl -sS -XPOST "$GITLAB_URL/projects" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN" \
        -H "Content-Type: application/json" \
        -d '{"name": "example"}' | jq
    {
        "id": 7822153,
        "description": null,
        "name": "example",
        ...
    }
    

3. Check Slack service

    curl -sS -XGET "$GITLAB_URL/projects/7822153/services/slack" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN" | jq
    {
        "id": null,
        "title": "Slack notifications",
        "created_at": null,
        "updated_at": null,
        "active": false,
        "push_events": true,
        "issues_events": true,
        "confidential_issues_events": true,
        "merge_requests_events": true,
        "tag_push_events": true,
        "note_events": true,
        "confidential_note_events": true,
        "pipeline_events": true,
        "wiki_page_events": true,
        "job_events": true,
        "properties": {
            "notify_only_broken_pipelines": true,
            "notify_only_default_branch": true
        }
    }
    

4. Turn off notification settings for Slack

    curl -sS -XPUT "$GITLAB_URL/projects/7822153/services/slack" \
        -H "Content-Type: application/json" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN" \
        -d '{"webhook": "https://google.com", "notify_only_broken_pipelines": false, "notify_only_default_branch": false}' | jq
    {
        "id": 41006774,
        "title": "Slack notifications",
        "created_at": "2018-08-08T19:11:39.973Z",
        "updated_at": "2018-08-08T19:11:39.973Z",
        "active": true,
        "push_events": true,
        "issues_events": true,
        "confidential_issues_events": true,
        "merge_requests_events": true,
        "tag_push_events": true,
        "note_events": true,
        "confidential_note_events": true,
        "pipeline_events": true,
        "wiki_page_events": true,
        "job_events": true,
        "properties": {
            "webhook": "https://google.com",
            "notify_only_broken_pipelines": false,
            "notify_only_default_branch": false
        }
    }
    

5. Disable Slack service

    curl -sS -XDELETE "$GITLAB_URL/projects/7822153/services/slack" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN"
    

6. Check Slack service again

    curl -sS -XGET "$GITLAB_URL/projects/7822153/services/slack" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN" | jq
    {
        "id": 41006774,
        "title": "Slack notifications",
        "created_at": "2018-08-08T19:11:39.973Z",
        "updated_at": "2018-08-08T19:13:56.190Z",
        "active": false,
        "push_events": true,
        "issues_events": true,
        "confidential_issues_events": true,
        "merge_requests_events": true,
        "tag_push_events": true,
        "note_events": true,
        "confidential_note_events": true,
        "pipeline_events": true,
        "wiki_page_events": true,
        "job_events": true,
        "properties": {
            "webhook": null,
            "username": null,
            "notify_only_broken_pipelines": null,
            "notify_only_default_branch": null,
            "push_channel": null,
            "issue_channel": null,
            "confidential_issue_channel": null,
            "merge_request_channel": null,
            "note_channel": null,
            "confidential_note_channel": null,
            "tag_push_channel": null,
            "pipeline_channel": null,
            "wiki_page_channel": null
        }
    }
    

7. Go to GitLab UI, https://gitlab.com/hypnoglow/example/services/slack/edit, and check "Active", "Notify only broken pipelines". Keep "Notify only default branch" unchecked. Click "Save Changes".

8. Check Slack service:

    curl -sS -XGET "$GITLAB_URL/projects/7822153/services/slack" \
        -H "PRIVATE-TOKEN: $GITLAB_TOKEN" | jq
    {
        "id": 41006774,
        "title": "Slack notifications",
        "created_at": "2018-08-08T19:11:39.973Z",
        "updated_at": "2018-08-08T19:16:49.899Z",
        "active": true,
        "push_events": true,
        "issues_events": true,
        "confidential_issues_events": true,
        "merge_requests_events": true,
        "tag_push_events": true,
        "note_events": true,
        "confidential_note_events": true,
        "pipeline_events": true,
        "wiki_page_events": true,
        "job_events": true,
        "properties": {
            "webhook": "https://google.com",
            "username": "",
            "notify_only_broken_pipelines": "1",
            "notify_only_default_branch": "0",
            "push_channel": "",
            "issue_channel": "",
            "confidential_issue_channel": "",
            "merge_request_channel": "",
            "note_channel": "",
            "confidential_note_channel": "",
            "tag_push_channel": "",
            "pipeline_channel": "",
            "wiki_page_channel": ""
        }
    }
    

Example Project

https://gitlab.com/hypnoglow/example

What is the current bug behavior?

notify_only_broken_pipelines is a boolean property, but has a string values "1" or "0".

What is the expected correct behavior?

notify_only_broken_pipelines should be only either true or false.

Output of checks

This bug happens on GitLab.com