llmgw/internal/web/chat_test.go

package web

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
)

func chatPage(t *testing.T, models []string) string {
	t.Helper()
	h := Chat(store.User{Email: "a@example.com", ProjectID: "proj"}, models, "v1")
	r := httptest.NewRequest(http.MethodGet, "http://x/chat", nil)
	w := httptest.NewRecorder()
	h(w, r)
	if w.Code != http.StatusOK {
		t.Fatalf("status %d", w.Code)
	}
	return w.Body.String()
}

func TestMathIsRenderedWithoutTrustingTheModel(t *testing.T) {
	// The ordering in the page is the safety argument, so it is worth asserting
	// rather than remembering: the reply is put in place with textContent and
	// only then walked for maths. KaTeX replaces the spans it recognises, so
	// nothing the model wrote is ever parsed as HTML.
	page := chatPage(t, []string{"m"})

	if !strings.Contains(page, "/_static/katex/katex.min.css") ||
		!strings.Contains(page, "/_static/katex/auto-render.min.js") {
		t.Fatal("the page does not load KaTeX")
	}
	// Vendored, not fetched: this gateway makes no outbound requests and is
	// expected to run where it could not.
	for _, cdn := range []string{"cdn.jsdelivr", "unpkg.com", "cdnjs.", "//katex.org"} {
		if strings.Contains(page, cdn) {
			t.Errorf("the page loads KaTeX from %s instead of the binary", cdn)
		}
	}

	if !strings.Contains(page, "trust: false") {
		t.Error("trust is not pinned off; \\href in model output would become a link")
	}
	if !strings.Contains(page, "throwOnError: false") {
		t.Error("a single malformed expression would take the whole reply with it")
	}

	// The reply still reaches the page as text first.
	if !strings.Contains(page, "out.textContent = reply") {
		t.Error("the reply is no longer written with textContent")
	}
	if strings.Contains(page, "innerHTML") {
		t.Error("the chat page assigns innerHTML somewhere")
	}
}

func TestMathIsRenderedOnceTheReplyIsComplete(t *testing.T) {
	// Typesettingevery  chunk would try to render half an expression on every token
	// and flicker through the whole reply.
	page := chatPage(t, []string{"m"})
	body := page[strings.Index(page, "form.onsubmit"):]

	renderAt := strings.Index(body, "renderMath(out)")
	streamAt := strings.Index(body, "out.textContent = reply")
	if renderAt < 0 || streamAt < 0 {
		t.Fatal("the streaming loop or the render call is missing")
	}
	if renderAt < streamAt {
		t.Error("maths is rendered before the text that carries it")
	}
}

func TestDisplayDelimitersComeBeforeInlineOnes(t *testing.T) {
	// $$…$$ has to be tried before $…$, or the opening $$ is read as an empty
	// inline expression and everything after it is wrong.
	page := chatPage(t, []string{"m"})
	dd := strings.Index(page, `left: "$$"`)
	d := strings.Index(page, `left: "$"`)
	if dd < 0 || d < 0 {
		t.Fatal("the delimiters are missing")
	}
	if dd > d {
		t.Error(`$ is tried before $$`)
	}
}

func TestTheChatPageOffersWhatItWasGiven(t *testing.T) {
	page := chatPage(t, []string{"alpha", "beta"})
	for _, m := range []string{"alpha", "beta"} {
		if !strings.Contains(page, `value="`+m+`"`) {
			t.Errorf("the picker does not offer %s", m)
		}
	}
	empty := chatPage(t, nil)
	if strings.Contains(empty, "<form id=\"composer\"") {
		t.Error("a composer was rendered with no model to send to")
	}
	if !strings.Contains(empty, "No models are available") {
		t.Error("the page does not explain why it is empty")
	}
}