feat: the assistant's search engine in Настройки - DuckDuckGo, a SearXNG of one's own, Brave Search or Tavily, with DuckDuckGo behind the chosen one

internal/server/search_test.go

@@ -1,6 +1,11 @@
 package server
 
 import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"strings"
 	"testing"
@@ -23,3 +28,50 @@ func TestParseDDGLite(t *testing.T) {
 		t.Fatalf("first: %+v", r)
 	}
 }
+
+// Each search engine of the settings, and DuckDuckGo when the chosen one
+// fails.
+func TestSearchProviders(t *testing.T) {
+	var gotKey, gotQ string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.URL.Path == "/search" && r.URL.Query().Get("format") == "json": // SearXNG
+			gotQ = r.URL.Query().Get("q")
+			fmt.Fprint(w, `{"results":[{"title":"SX","url":"https://a.example/","content":"from searx"}]}`)
+		case r.URL.Path == "/res/v1/web/search": // Brave
+			gotKey, gotQ = r.Header.Get("X-Subscription-Token"), r.URL.Query().Get("q")
+			fmt.Fprint(w, `{"web":{"results":[{"title":"BR","url":"https://b.example/","description":"from <strong>brave</strong>"}]}}`)
+		case r.URL.Path == "/search" && r.Method == http.MethodPost: // Tavily
+			var in map[string]any
+			_ = json.NewDecoder(r.Body).Decode(&in)
+			gotKey, gotQ = r.Header.Get("Authorization"), in["query"].(string)
+			fmt.Fprint(w, `{"results":[{"title":"TV","url":"https://t.example/","content":"from tavily"}]}`)
+		default:
+			http.Error(w, "no", 500)
+		}
+	}))
+	defer srv.Close()
+	braveURL, tavilyURL = srv.URL+"/res/v1/web/search", srv.URL+"/search"
+	ctx := context.Background()
+
+	rs, err := searchWith(ctx, searchConf{Engine: "searxng", URL: srv.URL}, "q1", 6)
+	if err != nil || len(rs) != 1 || rs[0].Title != "SX" || gotQ != "q1" {
+		t.Fatalf("searxng: %+v %v", rs, err)
+	}
+	rs, err = searchWith(ctx, searchConf{Engine: "brave", Key: "bk"}, "q2", 6)
+	if err != nil || rs[0].Snippet != "from brave" || gotKey != "bk" || gotQ != "q2" {
+		t.Fatalf("brave: %+v %v %q", rs, err, gotKey)
+	}
+	rs, err = searchWith(ctx, searchConf{Engine: "tavily", Key: "tk"}, "q3", 6)
+	if err != nil || rs[0].Title != "TV" || gotKey != "Bearer tk" || gotQ != "q3" {
+		t.Fatalf("tavily: %+v %v %q", rs, err, gotKey)
+	}
+	// The chosen one fails: DuckDuckGo instead (stood in for here).
+	ddgSearch = func(ctx context.Context, q string, n int) ([]searchResult, error) {
+		return []searchResult{{Title: "DDG"}}, nil
+	}
+	rs, err = searchWith(ctx, searchConf{Engine: "searxng", URL: srv.URL + "/broken"}, "q4", 6)
+	if err != nil || rs[0].Title != "DDG" {
+		t.Fatalf("fallback: %+v %v", rs, err)
+	}
+}