ReleaseCollection.cs

using System;
using System.Linq;

namespace NGitLab.Mock;

public class ReleaseCollection : Collection<ReleaseInfo>
{
    private Project Project => (Project)Parent;

    public ReleaseCollection(GitLabObject parent)
        : base(parent)
    {
    }

    public ReleaseInfo GetByTagName(string tagName)
    {
        return this.FirstOrDefault(r => string.Equals(r.TagName, tagName, StringComparison.Ordinal));
    }

    public override void Add(ReleaseInfo release)
    {
        if (release is null)
            throw new ArgumentNullException(nameof(release));

        if (release.TagName == default || Project.Repository.GetTags().FirstOrDefault(t => t.FriendlyName.Equals(release.TagName, StringComparison.Ordinal)) == null)
        {
            throw new ArgumentException($"Tag '{release.TagName}' invalid or not found", nameof(release));
        }

        if (release.Name == default)
        {
            release.Name = release.TagName;
        }

        if (GetByTagName(release.TagName) != null)
        {
            throw new GitLabException("Release already exists");
        }

        base.Add(release);
    }

    public ReleaseInfo Add(string tagName, string name, string description, User user)
    {
        return Add(tagName, name, reference: null, description, user);
    }

    public ReleaseInfo Add(string tagName, string name, string reference, string description, User user)
    {
        if (tagName is null)
            throw new ArgumentNullException(nameof(tagName));
        if (user is null)
            throw new ArgumentNullException(nameof(user));

        if (!Project.Repository.GetTags().Any(r => string.Equals(r.FriendlyName, tagName, StringComparison.Ordinal)))
        {
            if (string.IsNullOrEmpty(reference))
                throw GitLabException.BadRequest("A reference must be set when the tag does not exist");

            Project.Repository.CreateTag(tagName);
        }

        var release = new ReleaseInfo
        {
            TagName = tagName,
            Name = name,
            Description = description,
            Author = user,
        };

        Add(release);
        return release;
    }
}