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/search/merge_test.go

@@ -0,0 +1,80 @@
+package search
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/ashie/gosearch/internal/contracts"
+)
+
+func TestMergeResponses_DedupResultsAndSets(t *testing.T) {
+	url1 := "https://example.com/a?x=1"
+	uPtr := &url1
+
+	r1 := contracts.SearchResponse{
+		Query:            "q",
+		NumberOfResults: 1,
+		Results: []contracts.MainResult{
+			{
+				Template: "default.html",
+				Title:    "Title1",
+				Content:  "C1",
+				URL:       uPtr,
+				Engine:    "wikipedia",
+				Score:     1.0,
+			},
+		},
+		Answers:       []map[string]any{{"title": "A1", "url": url1}},
+		Corrections:   []string{"corr1", "corr2"},
+		Suggestions:   []string{"s1", "s2"},
+		Infoboxes:     []map[string]any{},
+		UnresponsiveEngines: [][2]string{},
+	}
+
+	r2 := contracts.SearchResponse{
+		Query:            "q",
+		NumberOfResults: 1,
+		Results: []contracts.MainResult{
+			{
+				Template: "default.html",
+				Title:    "Title1",
+				Content:  "C2",
+				URL:       uPtr,
+				Engine:    "wikipedia",
+				Score:     2.0,
+			},
+		},
+		Answers:     []map[string]any{{"title": "A1", "url": url1}},
+		Corrections: []string{"corr2", "corr3"},
+		Suggestions: []string{"s2", "s3"},
+		Infoboxes:   []map[string]any{},
+		UnresponsiveEngines: [][2]string{},
+	}
+
+	merged := MergeResponses([]contracts.SearchResponse{r1, r2})
+
+	if merged.Query != "q" {
+		t.Fatalf("expected query q, got %q", merged.Query)
+	}
+	if merged.NumberOfResults != 1 {
+		t.Fatalf("expected number_of_results max=1, got %d", merged.NumberOfResults)
+	}
+	if len(merged.Results) != 1 {
+		t.Fatalf("expected 1 merged result, got %d", len(merged.Results))
+	}
+
+	// Corrections/suggestions should be unioned.
+	joinedCorr := strings.Join(merged.Corrections, ",")
+	if !strings.Contains(joinedCorr, "corr1") || !strings.Contains(joinedCorr, "corr2") || !strings.Contains(joinedCorr, "corr3") {
+		t.Fatalf("expected unioned corrections, got %v", merged.Corrections)
+	}
+	joinedSug := strings.Join(merged.Suggestions, ",")
+	if !strings.Contains(joinedSug, "s1") || !strings.Contains(joinedSug, "s2") || !strings.Contains(joinedSug, "s3") {
+		t.Fatalf("expected unioned suggestions, got %v", merged.Suggestions)
+	}
+
+	if len(merged.Answers) != 1 {
+		t.Fatalf("expected 1 merged answer, got %d", len(merged.Answers))
+	}
+}
+