discourse-ai/spec/lib/modules/ai_bot/personas/persona_spec.rb

#frozen_string_literal: true

class TestPersona < DiscourseAi::AiBot::Personas::Persona
  def tools
    [
      DiscourseAi::AiBot::Tools::ListTags,
      DiscourseAi::AiBot::Tools::Search,
      DiscourseAi::AiBot::Tools::Image,
    ]
  end

  def system_prompt
    <<~PROMPT
      {site_url}
      {site_title}
      {site_description}
      {participants}
      {time}
    PROMPT
  end
end

RSpec.describe DiscourseAi::AiBot::Personas::Persona do
  let :persona do
    TestPersona.new
  end

  let :topic_with_users do
    topic = Topic.new
    topic.allowed_users = [User.new(username: "joe"), User.new(username: "jane")]
    topic
  end

  after do
    # we are rolling back transactions so we can create poison cache
    AiPersona.persona_cache.flush!
  end

  let(:context) do
    {
      site_url: Discourse.base_url,
      site_title: "test site title",
      site_description: "test site description",
      time: Time.zone.now,
      participants: topic_with_users.allowed_users.map(&:username).join(", "),
    }
  end

  fab!(:user)

  it "renders the system prompt" do
    freeze_time

    rendered = persona.craft_prompt(context)
    system_message = rendered.messages.first[:content]

    expect(system_message).to include(Discourse.base_url)
    expect(system_message).to include("test site title")
    expect(system_message).to include("test site description")
    expect(system_message).to include("joe, jane")
    expect(system_message).to include(Time.zone.now.to_s)

    tools = rendered.tools

    expect(tools.find { |t| t[:name] == "search" }).to be_present
    expect(tools.find { |t| t[:name] == "tags" }).to be_present

    # needs to be configured so it is not available
    expect(tools.find { |t| t[:name] == "image" }).to be_nil
  end

  it "can correctly parse arrays in tools" do
    SiteSetting.ai_openai_api_key = "123"

    # Dall E tool uses an array for params
    xml = <<~XML
      <function_calls>
        <invoke>
        <tool_name>dall_e</tool_name>
        <tool_id>call_JtYQMful5QKqw97XFsHzPweB</tool_id>
        <parameters>
        <prompts>["cat oil painting", "big car"]</prompts>
        </parameters>
        </invoke>
        <invoke>
        <tool_name>dall_e</tool_name>
        <tool_id>abc</tool_id>
        <parameters>
        <prompts>["pic3"]</prompts>
        </parameters>
        </invoke>
        <invoke>
        <tool_name>unknown</tool_name>
        <tool_id>abc</tool_id>
        <parameters>
        <prompts>["pic3"]</prompts>
        </parameters>
        </invoke>
      </function_calls>
    XML
    dall_e1, dall_e2 = tools = DiscourseAi::AiBot::Personas::DallE3.new.find_tools(xml)
    expect(dall_e1.parameters[:prompts]).to eq(["cat oil painting", "big car"])
    expect(dall_e2.parameters[:prompts]).to eq(["pic3"])
    expect(tools.length).to eq(2)
  end

  describe "custom personas" do
    it "is able to find custom personas" do
      Group.refresh_automatic_groups!

      # define an ai persona everyone can see
      persona =
        AiPersona.create!(
          name: "zzzpun_bot",
          description: "you write puns",
          system_prompt: "you are pun bot",
          commands: ["ImageCommand"],
          allowed_group_ids: [Group::AUTO_GROUPS[:trust_level_0]],
        )

      custom_persona = DiscourseAi::AiBot::Personas::Persona.all(user: user).last
      expect(custom_persona.name).to eq("zzzpun_bot")
      expect(custom_persona.description).to eq("you write puns")

      instance = custom_persona.new
      expect(instance.tools).to eq([DiscourseAi::AiBot::Tools::Image])
      expect(instance.craft_prompt(context).messages.first[:content]).to eq("you are pun bot")

      # should update
      persona.update!(name: "zzzpun_bot2")
      custom_persona = DiscourseAi::AiBot::Personas::Persona.all(user: user).last
      expect(custom_persona.name).to eq("zzzpun_bot2")

      # can be disabled
      persona.update!(enabled: false)
      last_persona = DiscourseAi::AiBot::Personas::Persona.all(user: user).last
      expect(last_persona.name).not_to eq("zzzpun_bot2")

      persona.update!(enabled: true)
      # no groups have access
      persona.update!(allowed_group_ids: [])

      last_persona = DiscourseAi::AiBot::Personas::Persona.all(user: user).last
      expect(last_persona.name).not_to eq("zzzpun_bot2")
    end
  end

  describe "available personas" do
    it "includes all personas by default" do
      Group.refresh_automatic_groups!

      # must be enabled to see it
      SiteSetting.ai_stability_api_key = "abc"
      SiteSetting.ai_google_custom_search_api_key = "abc"
      SiteSetting.ai_google_custom_search_cx = "abc123"

      # should be ordered by priority and then alpha
      expect(DiscourseAi::AiBot::Personas::Persona.all(user: user)).to eq(
        [
          DiscourseAi::AiBot::Personas::General,
          DiscourseAi::AiBot::Personas::Artist,
          DiscourseAi::AiBot::Personas::Creative,
          DiscourseAi::AiBot::Personas::DiscourseHelper,
          DiscourseAi::AiBot::Personas::GithubHelper,
          DiscourseAi::AiBot::Personas::Researcher,
          DiscourseAi::AiBot::Personas::SettingsExplorer,
          DiscourseAi::AiBot::Personas::SqlHelper,
        ],
      )

      # omits personas if key is missing
      SiteSetting.ai_stability_api_key = ""
      SiteSetting.ai_google_custom_search_api_key = ""

      expect(DiscourseAi::AiBot::Personas::Persona.all(user: user)).to contain_exactly(
        DiscourseAi::AiBot::Personas::General,
        DiscourseAi::AiBot::Personas::SqlHelper,
        DiscourseAi::AiBot::Personas::SettingsExplorer,
        DiscourseAi::AiBot::Personas::Creative,
        DiscourseAi::AiBot::Personas::DiscourseHelper,
        DiscourseAi::AiBot::Personas::GithubHelper,
      )

      AiPersona.find(
        DiscourseAi::AiBot::Personas::Persona.system_personas[
          DiscourseAi::AiBot::Personas::General
        ],
      ).update!(enabled: false)

      expect(DiscourseAi::AiBot::Personas::Persona.all(user: user)).to contain_exactly(
        DiscourseAi::AiBot::Personas::SqlHelper,
        DiscourseAi::AiBot::Personas::SettingsExplorer,
        DiscourseAi::AiBot::Personas::Creative,
        DiscourseAi::AiBot::Personas::DiscourseHelper,
        DiscourseAi::AiBot::Personas::GithubHelper,
      )
    end
  end

  describe "#craft_prompt" do
    before do
      Group.refresh_automatic_groups!
      SiteSetting.ai_embeddings_discourse_service_api_endpoint = "http://test.com"
      SiteSetting.ai_embeddings_enabled = true
    end

    let(:ai_persona) { DiscourseAi::AiBot::Personas::Persona.all(user: user).first.new }

    let(:with_cc) do
      context.merge(conversation_context: [{ content: "Tell me the time", type: :user }])
    end

    context "when a persona has no uploads" do
      it "doesn't include RAG guidance" do
        guidance_fragment =
          "The following texts will give you additional guidance to elaborate a response."

        expect(ai_persona.craft_prompt(with_cc).messages.first[:content]).not_to include(
          guidance_fragment,
        )
      end
    end

    context "when a persona has RAG uploads" do
      fab!(:upload)

      def stub_fragments(limit, expected_limit: nil)
        candidate_ids = []

        limit.times do |i|
          candidate_ids << Fabricate(
            :rag_document_fragment,
            fragment: "fragment-n#{i}",
            ai_persona_id: ai_persona.id,
            upload: upload,
          ).id
        end

        DiscourseAi::Embeddings::VectorRepresentations::BgeLargeEn
          .any_instance
          .expects(:asymmetric_rag_fragment_similarity_search)
          .with { |args, kwargs| kwargs[:limit] == (expected_limit || limit) }
          .returns(candidate_ids)
      end

      before do
        stored_ai_persona = AiPersona.find(ai_persona.id)
        UploadReference.ensure_exist!(target: stored_ai_persona, upload_ids: [upload.id])

        context_embedding = [0.049382, 0.9999]
        EmbeddingsGenerationStubs.discourse_service(
          SiteSetting.ai_embeddings_model,
          with_cc.dig(:conversation_context, 0, :content),
          context_embedding,
        )
      end

      context "when the system prompt has an uploads placeholder" do
        before { stub_fragments(10) }

        it "replaces the placeholder with the fragments" do
          custom_persona_record =
            AiPersona.create!(
              name: "custom",
              description: "description",
              system_prompt: "instructions\n{uploads}\nmore instructions",
              allowed_group_ids: [Group::AUTO_GROUPS[:trust_level_0]],
            )
          UploadReference.ensure_exist!(target: custom_persona_record, upload_ids: [upload.id])
          custom_persona =
            DiscourseAi::AiBot::Personas::Persona.find_by(
              id: custom_persona_record.id,
              user: user,
            ).new

          crafted_system_prompt = custom_persona.craft_prompt(with_cc).messages.first[:content]

          expect(crafted_system_prompt).to include("fragment-n0")

          expect(crafted_system_prompt.ends_with?("</guidance>")).to eq(false)
        end
      end

      context "when persona allows for less fragments" do
        before { stub_fragments(3) }

        it "will only pick 3 fragments" do
          custom_ai_persona =
            Fabricate(
              :ai_persona,
              name: "custom",
              rag_conversation_chunks: 3,
              allowed_group_ids: [Group::AUTO_GROUPS[:trust_level_0]],
            )

          UploadReference.ensure_exist!(target: custom_ai_persona, upload_ids: [upload.id])

          custom_persona =
            DiscourseAi::AiBot::Personas::Persona.find_by(id: custom_ai_persona.id, user: user).new

          expect(custom_persona.class.rag_conversation_chunks).to eq(3)

          crafted_system_prompt = custom_persona.craft_prompt(with_cc).messages.first[:content]

          expect(crafted_system_prompt).to include("fragment-n0")
          expect(crafted_system_prompt).to include("fragment-n1")
          expect(crafted_system_prompt).to include("fragment-n2")
          expect(crafted_system_prompt).not_to include("fragment-n3")
        end
      end

      context "when the reranker is available" do
        before do
          SiteSetting.ai_hugging_face_tei_reranker_endpoint = "https://test.reranker.com"

          # hard coded internal implementation, reranker takes x5 number of chunks
          stub_fragments(15, expected_limit: 50) # Mimic limit being more than 10 results
        end

        it "uses the re-ranker to reorder the fragments and pick the top 10 candidates" do
          expected_reranked = (0..14).to_a.reverse.map { |idx| { index: idx } }

          WebMock.stub_request(:post, "https://test.reranker.com/rerank").to_return(
            status: 200,
            body: JSON.dump(expected_reranked),
          )

          crafted_system_prompt = ai_persona.craft_prompt(with_cc).messages.first[:content]

          expect(crafted_system_prompt).to include("fragment-n14")
          expect(crafted_system_prompt).to include("fragment-n13")
          expect(crafted_system_prompt).to include("fragment-n12")

          expect(crafted_system_prompt).not_to include("fragment-n4") # Fragment #11 not included
        end
      end

      context "when the reranker is not available" do
        before { stub_fragments(10) }

        it "picks the first 10 candidates from the similarity search" do
          crafted_system_prompt = ai_persona.craft_prompt(with_cc).messages.first[:content]

          expect(crafted_system_prompt).to include("fragment-n0")
          expect(crafted_system_prompt).to include("fragment-n1")
          expect(crafted_system_prompt).to include("fragment-n2")

          expect(crafted_system_prompt).not_to include("fragment-n10") # Fragment #10 not included
        end
      end
    end
  end
end