feat(tools): code_search (org-wide fan-out)

When repo is omitted, lists owner's repos then concurrently searches
each one (semaphore cap 5, 5s per-repo timeout). Merges and sorts
hits by score desc with deterministic tiebreak. Partial failures
tracked in partial_repos without aborting the whole fan-out.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/tools/code_search_test.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"gitea.d-ma.be/mathias/gitea-mcp/internal/allowlist"
@@ -65,9 +66,122 @@ func TestCodeSearchRequiresQ(t *testing.T) {
 	assert.True(t, errors.Is(err, gitea.ErrValidation))
 }
 
-func TestCodeSearchFanOutNotYetImplemented(t *testing.T) {
-	tool := tools.NewCodeSearch(gitea.NewClient("http://unused", ""), allowlist.New([]string{"mathias"}))
-	_, err := tool.Call(context.Background(), json.RawMessage(`{"q":"foo","owner":"mathias"}`))
-	require.Error(t, err)
-	assert.True(t, errors.Is(err, gitea.ErrValidation))
+func TestCodeSearchFanOutHappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		switch r.URL.Path {
+		case "/api/v1/users/mathias/repos":
+			_, _ = w.Write([]byte(`[
+				{"name":"infra","full_name":"mathias/infra","default_branch":"main"},
+				{"name":"gitea-mcp","full_name":"mathias/gitea-mcp","default_branch":"main"}
+			]`))
+		case "/api/v1/repos/mathias/infra/search":
+			_, _ = w.Write([]byte(`{"data":[{"path":"main.go","snippet":"infra hit","html_url":"http://x/infra/main.go","score":2.0}],"ok":true}`))
+		case "/api/v1/repos/mathias/gitea-mcp/search":
+			_, _ = w.Write([]byte(`{"data":[{"path":"cmd/main.go","snippet":"gitea-mcp hit","html_url":"http://x/gitea-mcp/main.go","score":1.0}],"ok":true}`))
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer srv.Close()
+
+	tool := tools.NewCodeSearch(gitea.NewClient(srv.URL, "tok"), allowlist.New([]string{"mathias"}))
+	out, err := tool.Call(context.Background(), json.RawMessage(`{"q":"hit","owner":"mathias"}`))
+	require.NoError(t, err)
+
+	var result struct {
+		Results []struct {
+			Repo    string `json:"repo"`
+			Path    string `json:"path"`
+			Snippet string `json:"snippet"`
+		} `json:"results"`
+		Partial bool `json:"partial"`
+	}
+	require.NoError(t, json.Unmarshal(out, &result))
+	assert.False(t, result.Partial)
+	require.Len(t, result.Results, 2)
+
+	repos := make([]string, 0, 2)
+	for _, r := range result.Results {
+		repos = append(repos, r.Repo)
+	}
+	assert.Contains(t, repos, "mathias/infra")
+	assert.Contains(t, repos, "mathias/gitea-mcp")
+}
+
+func TestCodeSearchFanOutPartialFailure(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		switch r.URL.Path {
+		case "/api/v1/users/mathias/repos":
+			_, _ = w.Write([]byte(`[
+				{"name":"infra","full_name":"mathias/infra","default_branch":"main"},
+				{"name":"broken","full_name":"mathias/broken","default_branch":"main"}
+			]`))
+		case "/api/v1/repos/mathias/infra/search":
+			_, _ = w.Write([]byte(`{"data":[{"path":"main.go","snippet":"infra hit","html_url":"http://x/infra/main.go","score":1.0}],"ok":true}`))
+		case "/api/v1/repos/mathias/broken/search":
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte(`{"message":"internal error"}`))
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer srv.Close()
+
+	tool := tools.NewCodeSearch(gitea.NewClient(srv.URL, "tok"), allowlist.New([]string{"mathias"}))
+	out, err := tool.Call(context.Background(), json.RawMessage(`{"q":"hit","owner":"mathias"}`))
+	require.NoError(t, err)
+
+	var result struct {
+		Results      []struct{ Repo string `json:"repo"` } `json:"results"`
+		Partial      bool                                  `json:"partial"`
+		PartialRepos []string                              `json:"partial_repos"`
+	}
+	require.NoError(t, json.Unmarshal(out, &result))
+	assert.True(t, result.Partial)
+	require.Len(t, result.PartialRepos, 1)
+	assert.Equal(t, "mathias/broken", result.PartialRepos[0])
+	require.Len(t, result.Results, 1)
+	assert.Equal(t, "mathias/infra", result.Results[0].Repo)
+}
+
+func TestCodeSearchFanOutSortsByScore(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		switch r.URL.Path {
+		case "/api/v1/users/mathias/repos":
+			_, _ = w.Write([]byte(`[
+				{"name":"alpha","full_name":"mathias/alpha","default_branch":"main"},
+				{"name":"beta","full_name":"mathias/beta","default_branch":"main"}
+			]`))
+		case "/api/v1/repos/mathias/alpha/search":
+			// low score
+			_, _ = w.Write([]byte(`{"data":[{"path":"a.go","snippet":"low","html_url":"http://x/alpha/a.go","score":1.0}],"ok":true}`))
+		case "/api/v1/repos/mathias/beta/search":
+			// high score
+			_, _ = w.Write([]byte(`{"data":[{"path":"b.go","snippet":"high","html_url":"http://x/beta/b.go","score":5.0}],"ok":true}`))
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer srv.Close()
+
+	tool := tools.NewCodeSearch(gitea.NewClient(srv.URL, "tok"), allowlist.New([]string{"mathias"}))
+	out, err := tool.Call(context.Background(), json.RawMessage(`{"q":"something","owner":"mathias"}`))
+	require.NoError(t, err)
+
+	var result struct {
+		Results []struct {
+			Snippet string  `json:"snippet"`
+			Score   float64 `json:"score"`
+		} `json:"results"`
+	}
+	require.NoError(t, json.Unmarshal(out, &result))
+	require.Len(t, result.Results, 2)
+	// First result must be the high-score one
+	assert.True(t, result.Results[0].Score > result.Results[1].Score,
+		"expected results sorted by score desc, got %v then %v",
+		result.Results[0].Score, result.Results[1].Score)
+	assert.True(t, strings.Contains(result.Results[0].Snippet, "high"))
 }