feat: build Go-based SearXNG-compatible search service

Implement an API-first Go rewrite with local engine adapters, upstream fallback, and Nix-based tooling so searches can run without matching the original UI while preserving response compatibility.

Made-with: Cursor

internal/engines/qwant_test.go

@@ -0,0 +1,94 @@
+package engines
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/ashie/gosearch/internal/contracts"
+)
+
+func TestQwantEngine_Web(t *testing.T) {
+	transport := roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		if r.Method != http.MethodGet {
+			return httpResponse(http.StatusMethodNotAllowed, "", ""), nil
+		}
+		if r.URL.Host != "api.qwant.com" {
+			return httpResponse(http.StatusNotFound, "", ""), nil
+		}
+		if r.URL.Path != "/v3/search/web" {
+			t.Fatalf("unexpected path: %s", r.URL.Path)
+		}
+
+		q := r.URL.Query().Get("q")
+		if q != "hugo" {
+			t.Fatalf("unexpected q: %q", q)
+		}
+		if r.URL.Query().Get("count") != "10" {
+			t.Fatalf("unexpected count: %q", r.URL.Query().Get("count"))
+		}
+		if r.URL.Query().Get("locale") != "en_US" {
+			t.Fatalf("unexpected locale: %q", r.URL.Query().Get("locale"))
+		}
+		if r.URL.Query().Get("safesearch") != "0" {
+			t.Fatalf("unexpected safesearch: %q", r.URL.Query().Get("safesearch"))
+		}
+		if r.URL.Query().Get("llm") != "false" {
+			t.Fatalf("unexpected llm: %q", r.URL.Query().Get("llm"))
+		}
+		if r.URL.Query().Get("tgp") != "3" {
+			t.Fatalf("unexpected tgp: %q", r.URL.Query().Get("tgp"))
+		}
+		if r.URL.Query().Get("offset") != "0" {
+			t.Fatalf("unexpected offset: %q", r.URL.Query().Get("offset"))
+		}
+
+		body := `{
+  "status": "success",
+  "data": {
+    "result": {
+      "items": {
+        "mainline": [
+          {
+            "type": "web",
+            "items": [
+              { "title": "Qwant Title", "url": "https://example.com/q", "desc": "Qwant description" }
+            ]
+          }
+        ]
+      }
+    }
+  }
+}`
+		return httpResponse(http.StatusOK, body, "application/json"), nil
+	})
+
+	client := &http.Client{Transport: transport}
+	engine := &QwantEngine{client: client, category: "web", resultsPerPage: 10}
+
+	resp, err := engine.Search(context.Background(), contracts.SearchRequest{
+		Query:      "hugo",
+		Pageno:     1,
+		Safesearch: 0,
+		Language:   "en",
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(resp.Results) != 1 {
+		t.Fatalf("expected 1 result, got %d", len(resp.Results))
+	}
+	if resp.Results[0].Title != "Qwant Title" {
+		t.Fatalf("unexpected title: %q", resp.Results[0].Title)
+	}
+	if resp.Results[0].Content != "Qwant description" {
+		t.Fatalf("unexpected content: %q", resp.Results[0].Content)
+	}
+	if resp.Results[0].URL == nil || *resp.Results[0].URL != "https://example.com/q" {
+		t.Fatalf("unexpected url: %v", resp.Results[0].URL)
+	}
+	if resp.Results[0].Engine != "qwant" {
+		t.Fatalf("unexpected engine: %q", resp.Results[0].Engine)
+	}
+}
+