Make the home page's AS name search work (closes #151)

The AS Name Search card on the home page said the search was coming soon.
It now asks the new GET /api/v1/search/as?q=<text> and lists the matches
as links to their AS pages. asinfo.Search ignores case, returns the first
matches up to a limit in AS number order, and counts all matches. An
empty q answers 400.

When the database has no record of an AS, its page and /api/v1/as/{asn}
take its handle and description from asinfo and still list its prefixes.
They answer 404 only for an AS with no record, no asinfo entry and no
prefix. AS 0 means no known origin: it always answers 404, and the search
never lists it.

Model: opus-5-5

internal/server/handlers.go

@@ -16,6 +16,7 @@ import (
 
 	"git.eeqj.de/sneak/routewatch/internal/database"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
 	"git.eeqj.de/sneak/routewatch/internal/templates"
 	asinfo "git.eeqj.de/sneak/routewatch/pkg/asinfo"
@@ -56,10 +57,18 @@ const (
 // Error messages an answer sends, in place of the error behind it where there
 // is one.
 const (
-	invalidPrefixMessage   = "Invalid prefix"
-	hostNotResolvedMessage = "could not resolve host name"
-	hostNotPublicMessage   = "host name has no public address"
-	tooManyTargetsMessage  = "Too many addresses or host names"
+	invalidPrefixMessage      = "Invalid prefix"
+	hostNotResolvedMessage    = "could not resolve host name"
+	hostNotPublicMessage      = "host name has no public address"
+	tooManyTargetsMessage     = "Too many addresses or host names"
+	searchQueryMissingMessage = "Missing search query"
+)
+
+// The AS name search reads the text it looks for from the URL query parameter
+// asSearchQueryParam, and answers with at most maxASSearchResults matches.
+const (
+	asSearchQueryParam = "q"
+	maxASSearchResults = 50
 )
 
 // IP versions as database.LiveRoute.IPVersion records them.
@@ -1001,11 +1010,12 @@ func (s *Server) handleASDetailJSON() http.HandlerFunc {
 	}
 }
 
-// splitRoutesByIPVersion groups routes into the IPv4 and the IPv6 ones.
+// splitRoutesByIPVersion groups routes into the IPv4 and the IPv6 ones. Neither
+// group is nil, so that a JSON answer holds [] for an empty one and not null.
 func splitRoutesByIPVersion(
 	routes []database.LiveRoute,
 ) ([]database.LiveRoute, []database.LiveRoute) {
-	var ipv4Routes, ipv6Routes []database.LiveRoute
+	ipv4Routes, ipv6Routes := []database.LiveRoute{}, []database.LiveRoute{}
 
 	for _, route := range routes {
 		if route.IPVersion == ipVersionV4 {
@@ -1105,6 +1115,56 @@ func (s *Server) handlePrefixDetailJSON() http.HandlerFunc {
 	}
 }
 
+// ASSearchResponse is the answer to an AS name search: the text searched for,
+// the number of ASes that match it, and the first maxASSearchResults of them in
+// AS number order.
+type ASSearchResponse struct {
+	Query   string        `json:"query"`
+	Total   int           `json:"total"`
+	Results []asinfo.Info `json:"results"`
+}
+
+// handleASSearch returns a handler that searches the AS list built into
+// asinfo for the text in the q parameter, without its leading and trailing
+// spaces. It answers 400 when no text is left.
+func (s *Server) handleASSearch() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		query := strings.TrimSpace(r.URL.Query().Get(asSearchQueryParam))
+		if query == "" {
+			s.writeJSONError(w, http.StatusBadRequest, searchQueryMissingMessage)
+
+			return
+		}
+
+		// AS 0 means no known origin and has no AS page, so the answer leaves
+		// it out. The matches come in AS number order, so AS 0 can only be the
+		// first. The search asks for one match more than the answer holds, to
+		// take its place.
+		results, total := asinfo.Search(query, maxASSearchResults+1)
+		if len(results) > 0 && results[0].ASN == ristypes.NoOrigin {
+			results = results[1:]
+			total--
+		}
+
+		results = results[:min(len(results), maxASSearchResults)]
+
+		// results is an empty list rather than nil when nothing matches, so
+		// that the answer holds [] and not null.
+		if results == nil {
+			results = []asinfo.Info{}
+		}
+
+		err := writeJSONSuccess(w, ASSearchResponse{
+			Query:   query,
+			Total:   total,
+			Results: results,
+		})
+		if err != nil {
+			s.logger.Error("Failed to encode AS search results", "error", err)
+		}
+	}
+}
+
 // handleASDetail returns a handler that serves the AS detail HTML page
 func (s *Server) handleASDetail() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

internal/server/handlers_internal_test.go

@@ -19,6 +19,7 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/database"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
 	"git.eeqj.de/sneak/routewatch/pkg/asinfo"
 )
@@ -26,6 +27,7 @@ import (
 // The prefix and peer addresses the prefix page tests store routes for.
 const (
 	testPrefixV4 = "192.0.2.0/24"
+	testPrefixV6 = "2001:db8::/32"
 	testPeerV4   = "198.51.100.1"
 	testPeerV6   = "2001:db8::1"
 )
@@ -194,7 +196,7 @@ func TestStatsHandlersAnswerFromMemory(t *testing.T) {
 }
 
 // newServerWithTestRoutes returns a server on a new database that holds a
-// route for testPrefixV4 and one for 2001:db8::/32.
+// route for testPrefixV4 and one for testPrefixV6.
 func newServerWithTestRoutes(t *testing.T) *Server {
 	t.Helper()
 
@@ -214,7 +216,7 @@ func newServerWithTestRoutes(t *testing.T) *Server {
 			NextHop: testPeerV4, LastUpdated: ts,
 		},
 		{
-			Prefix: "2001:db8::/32", MaskLength: 32, IPVersion: 6,
+			Prefix: testPrefixV6, MaskLength: 32, IPVersion: 6,
 			OriginASN: 64501, PeerIP: testPeerV6, ASPath: []int{64501},
 			NextHop: testPeerV6, LastUpdated: ts,
 		},
@@ -1166,6 +1168,386 @@ func TestIPLookupHidesPrivateAddresses(t *testing.T) {
 	}
 }
 
+// asSearchPath is the path of the AS name search.
+const asSearchPath = "/api/v1/search/as"
+
+// searchAS sends an AS name search with the URL query rawQuery through s's
+// router, expects a 200 answer, and returns its data.
+func searchAS(t *testing.T, s *Server, rawQuery string) ASSearchResponse {
+	t.Helper()
+
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+		t.Context(), http.MethodGet, asSearchPath+"?"+rawQuery, nil))
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("%s: status %d, want %d; body %s",
+			rawQuery, rec.Code, http.StatusOK, rec.Body)
+	}
+
+	var body struct {
+		Data ASSearchResponse `json:"data"`
+	}
+
+	err := json.Unmarshal(rec.Body.Bytes(), &body)
+	if err != nil {
+		t.Fatalf("%s: decoding the answer %q: %v", rawQuery, rec.Body, err)
+	}
+
+	return body.Data
+}
+
+// TestASSearchAnswersMatches searches for Cloudflare's handle in lower case,
+// with spaces around it, and expects AS13335 among the matches. Before the fix
+// there was no AS name search, and the home page's search card said it was
+// coming soon (https://git.eeqj.de/sneak/routewatch/issues/151).
+func TestASSearchAnswersMatches(t *testing.T) {
+	t.Parallel()
+
+	const query = "cloudflarenet"
+
+	data := searchAS(t, newServerWithTestRoutes(t), "q=%20"+query+"%20")
+
+	if data.Query != query {
+		t.Errorf("query %q, want %q", data.Query, query)
+	}
+
+	if data.Total != len(data.Results) {
+		t.Errorf("total %d, but %d results", data.Total, len(data.Results))
+	}
+
+	cloudflare := asinfo.Info{
+		ASN: 13335, Handle: "CLOUDFLARENET", Description: "Cloudflare, Inc.",
+	}
+	if !slices.Contains(data.Results, cloudflare) {
+		t.Errorf("results %v do not hold %v", data.Results, cloudflare)
+	}
+}
+
+// TestASSearchAnswersEmptyListWhenNothingMatches expects a search that matches
+// nothing to answer 200 with a total of 0 and an empty list, not null.
+func TestASSearchAnswersEmptyListWhenNothingMatches(t *testing.T) {
+	t.Parallel()
+
+	data := searchAS(t, newServerWithTestRoutes(t), "q=XYZABC123456")
+
+	if data.Total != 0 || data.Results == nil || len(data.Results) != 0 {
+		t.Errorf("total %d and results %#v, want 0 and an empty list",
+			data.Total, data.Results)
+	}
+}
+
+// TestASSearchAnswers400ForEmptyQuery expects a search with no q, an empty q
+// or a q of only spaces to answer 400 with the JSON error body.
+func TestASSearchAnswers400ForEmptyQuery(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTestRoutes(t)
+
+	for _, path := range []string{
+		asSearchPath, asSearchPath + "?q=", asSearchPath + "?q=%20%20",
+	} {
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil))
+
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("%s: status %d, want %d; body %s",
+				path, rec.Code, http.StatusBadRequest, rec.Body)
+		}
+
+		checkJSONErrorCode(t, path, rec, http.StatusBadRequest)
+		checkJSONErrorMessage(t, path, rec, searchQueryMissingMessage)
+	}
+}
+
+// TestASSearchShowsFirstMatchesAndTotal searches for a word with more matches
+// than an answer holds, and expects the first maxASSearchResults of them, in
+// AS number order, and the number of all of them.
+func TestASSearchShowsFirstMatchesAndTotal(t *testing.T) {
+	t.Parallel()
+
+	const query = "university"
+
+	all, _ := asinfo.Search(query, asinfo.Total())
+	if len(all) <= maxASSearchResults {
+		t.Fatalf("Search(%q) has %d matches; the test needs more than %d",
+			query, len(all), maxASSearchResults)
+	}
+
+	data := searchAS(t, newServerWithTestRoutes(t), "q="+query)
+
+	if data.Total != len(all) {
+		t.Errorf("total %d, want %d", data.Total, len(all))
+	}
+
+	if !slices.Equal(data.Results, all[:maxASSearchResults]) {
+		t.Errorf("results %v, want the first %d matches %v",
+			data.Results, maxASSearchResults, all[:maxASSearchResults])
+	}
+}
+
+// The AS numbers the AS detail tests ask for. storedASN originates the route
+// for testPrefixV4 and is in the database. routeOnlyASN originates the route
+// for testPrefixV6, but the database has no record of the AS itself, as when
+// a route is stored before its AS. builtInOnlyASN is in the AS list built into
+// asinfo but not in the database. unknownASN is in neither.
+const (
+	storedASN      = 64500
+	routeOnlyASN   = 64501
+	builtInOnlyASN = 15169
+	unknownASN     = 4200000000
+)
+
+// zeroDate is how a page writes a time that was never set.
+const zeroDate = "0001-01-01"
+
+// firstSeenCard is the label of the AS page's first-seen date.
+const firstSeenCard = `<div class="info-label">First Seen</div>`
+
+// newServerWithStoredAS returns newServerWithTestRoutes's server with storedASN
+// added to the database. It fails the test when the AS list built into asinfo
+// lacks routeOnlyASN or builtInOnlyASN, or holds unknownASN.
+func newServerWithStoredAS(t *testing.T) *Server {
+	t.Helper()
+
+	for _, asn := range []int{routeOnlyASN, builtInOnlyASN} {
+		if _, ok := asinfo.Get(asn); !ok {
+			t.Fatalf("AS%d is not in the AS info data", asn)
+		}
+	}
+
+	if _, ok := asinfo.Get(unknownASN); ok {
+		t.Fatalf("AS%d is in the AS info data", unknownASN)
+	}
+
+	s := newServerWithTestRoutes(t)
+
+	_, err := s.db.GetOrCreateASN(storedASN, time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC))
+	if err != nil {
+		t.Fatalf("GetOrCreateASN: %v", err)
+	}
+
+	return s
+}
+
+// TestASDetailJSONAnswersBuiltInAS asks /api/v1/as/ for each of the ASes above.
+// All but unknownASN answer 200 with the handle and description from the
+// built-in AS list and their prefixes, as lists even when empty. Only storedASN
+// has a first_seen time. unknownASN answers 404. Before the fix builtInOnlyASN
+// answered 404, so a result of the AS name search could lead nowhere
+// (https://git.eeqj.de/sneak/routewatch/issues/151), and routeOnlyASN listed
+// no prefixes.
+func TestASDetailJSONAnswersBuiltInAS(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithStoredAS(t)
+
+	tests := []struct {
+		asn           int
+		wantCode      int
+		wantPrefixes  []string
+		wantFirstSeen bool
+	}{
+		{storedASN, http.StatusOK, []string{testPrefixV4}, true},
+		{routeOnlyASN, http.StatusOK, []string{testPrefixV6}, false},
+		{builtInOnlyASN, http.StatusOK, nil, false},
+		{unknownASN, http.StatusNotFound, nil, false},
+	}
+
+	for _, tt := range tests {
+		path := "/api/v1/as/" + strconv.Itoa(tt.asn)
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil))
+
+		if rec.Code != tt.wantCode {
+			t.Errorf("%s: status %d, want %d; body %s",
+				path, rec.Code, tt.wantCode, rec.Body)
+
+			continue
+		}
+
+		if tt.wantCode != http.StatusOK {
+			checkJSONErrorCode(t, path, rec, tt.wantCode)
+
+			continue
+		}
+
+		//nolint:tagliatelle // field names are the existing JSON API
+		var body struct {
+			Data struct {
+				ASN          database.ASN         `json:"asn"`
+				IPv4Prefixes []database.LiveRoute `json:"ipv4_prefixes"`
+				IPv6Prefixes []database.LiveRoute `json:"ipv6_prefixes"`
+			} `json:"data"`
+		}
+
+		err := json.Unmarshal(rec.Body.Bytes(), &body)
+		if err != nil {
+			t.Errorf("%s: decoding the answer %q: %v", path, rec.Body, err)
+
+			continue
+		}
+
+		info, _ := asinfo.Get(tt.asn)
+		got := body.Data.ASN
+
+		if got.ASN != tt.asn || got.Handle != info.Handle ||
+			got.Description != info.Description {
+			t.Errorf("%s: AS %d %q %q, want %d %q %q", path, got.ASN,
+				got.Handle, got.Description, tt.asn, info.Handle, info.Description)
+		}
+
+		if body.Data.IPv4Prefixes == nil || body.Data.IPv6Prefixes == nil {
+			t.Errorf("%s: a prefix list is null; body %s", path, rec.Body)
+		}
+
+		routes := slices.Concat(body.Data.IPv4Prefixes, body.Data.IPv6Prefixes)
+
+		gotPrefixes := make([]string, 0, len(routes))
+		for _, route := range routes {
+			gotPrefixes = append(gotPrefixes, route.Prefix)
+		}
+
+		if !slices.Equal(gotPrefixes, tt.wantPrefixes) {
+			t.Errorf("%s: prefixes %v, want %v", path, gotPrefixes, tt.wantPrefixes)
+		}
+
+		gotFirstSeen := strings.Contains(rec.Body.String(), `"first_seen"`)
+		if gotFirstSeen != tt.wantFirstSeen {
+			t.Errorf("%s: has first_seen %t, want %t; body %s",
+				path, gotFirstSeen, tt.wantFirstSeen, rec.Body)
+		}
+	}
+}
+
+// TestASDetailPageShowsBuiltInAS asks /as/ for each of the ASes above. All but
+// unknownASN answer 200 with the handle and description from the built-in AS
+// list. storedASN and routeOnlyASN list their prefixes, and builtInOnlyASN says
+// the AS announces none. Only storedASN shows a first-seen date, and no page
+// shows a date that was never set. unknownASN answers 404. Before the fix
+// builtInOnlyASN answered 404, so a result of the AS name search led nowhere
+// (https://git.eeqj.de/sneak/routewatch/issues/151), and routeOnlyASN listed no
+// prefixes.
+func TestASDetailPageShowsBuiltInAS(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithStoredAS(t)
+
+	tests := []struct {
+		asn           int
+		wantCode      int
+		wantText      string
+		wantFirstSeen bool
+	}{
+		{storedASN, http.StatusOK, testPrefixV4, true},
+		{routeOnlyASN, http.StatusOK, testPrefixV6, false},
+		{builtInOnlyASN, http.StatusOK, "No prefixes announced by this AS", false},
+		{unknownASN, http.StatusNotFound, "", false},
+	}
+
+	for _, tt := range tests {
+		path := "/as/" + strconv.Itoa(tt.asn)
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil))
+
+		if rec.Code != tt.wantCode {
+			t.Errorf("%s: status %d, want %d; body %s",
+				path, rec.Code, tt.wantCode, rec.Body)
+
+			continue
+		}
+
+		if tt.wantCode != http.StatusOK {
+			continue
+		}
+
+		info, _ := asinfo.Get(tt.asn)
+		page := rec.Body.String()
+
+		for _, want := range []string{
+			html.EscapeString(info.Handle),
+			html.EscapeString(info.Description),
+			tt.wantText,
+		} {
+			if !strings.Contains(page, want) {
+				t.Errorf("%s: page does not show %q", path, want)
+			}
+		}
+
+		if strings.Contains(page, zeroDate) {
+			t.Errorf("%s: page shows the date %s", path, zeroDate)
+		}
+
+		gotFirstSeen := strings.Contains(page, firstSeenCard)
+		if gotFirstSeen != tt.wantFirstSeen {
+			t.Errorf("%s: shows a first-seen date %t, want %t",
+				path, gotFirstSeen, tt.wantFirstSeen)
+		}
+	}
+}
+
+// TestNoOriginHasNoASAnswers stores a route with no known origin, which has
+// origin AS 0 (https://git.eeqj.de/sneak/routewatch/issues/75). It expects
+// /as/0 and /api/v1/as/0 to answer 404. It expects a search for "iana" to leave
+// AS 0 out of its results and its total, although the AS list built into
+// asinfo holds AS 0. Before the fix both AS answers were 200 and listed the
+// route's prefix, and the search listed AS 0 first.
+func TestNoOriginHasNoASAnswers(t *testing.T) {
+	t.Parallel()
+
+	const (
+		noOriginPrefix = "203.0.113.0/24"
+		query          = "iana"
+	)
+
+	s := newServerWithTestRoutes(t)
+
+	err := s.db.UpsertLiveRouteBatch([]*database.LiveRoute{{
+		Prefix: noOriginPrefix, MaskLength: 24, IPVersion: 4,
+		OriginASN: ristypes.NoOrigin, PeerIP: testPeerV4,
+		ASPath: []int{64500, 64501, 64502}, NextHop: testPeerV4,
+		LastUpdated: time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC),
+	}})
+	if err != nil {
+		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+	}
+
+	asn := strconv.Itoa(ristypes.NoOrigin)
+
+	for _, path := range []string{"/as/" + asn, "/api/v1/as/" + asn} {
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil))
+
+		if rec.Code != http.StatusNotFound {
+			t.Errorf("%s: status %d, want %d; body %s",
+				path, rec.Code, http.StatusNotFound, rec.Body)
+		}
+	}
+
+	first, total := asinfo.Search(query, 1)
+	if len(first) != 1 || first[0].ASN != ristypes.NoOrigin {
+		t.Fatalf("AS%d is not the first match for %q in the AS info data",
+			ristypes.NoOrigin, query)
+	}
+
+	data := searchAS(t, s, "q="+query)
+
+	for _, info := range data.Results {
+		if info.ASN == ristypes.NoOrigin {
+			t.Errorf("the search for %q lists AS%d", query, info.ASN)
+		}
+	}
+
+	if data.Total != total-1 {
+		t.Errorf("the search for %q has a total of %d, want %d",
+			query, data.Total, total-1)
+	}
+}
+
 // settledGoroutineCount lets transient goroutines finish, then reports the
 // current count.
 func settledGoroutineCount() int {

internal/server/routes.go

@@ -87,6 +87,7 @@ func (s *Server) setupRoutes() {
 		r.Get("/ip/{ip}", s.handleIPLookup())
 		r.Get("/as/{asn}", s.handleASDetailJSON())
 		r.Get("/prefix/{prefix}/{len}", s.handlePrefixDetailJSON())
+		r.Get("/search/as", s.handleASSearch())
 	})
 
 	s.router = r

internal/server/server.go

@@ -1,4 +1,8 @@
-// Package server provides HTTP endpoints for status monitoring and statistics
+// Package server serves RouteWatch's web pages and JSON API:
+//   - the home page, the status figures and the health check
+//   - the AS, prefix and prefix length pages, and the JSON answers behind them
+//   - the IP lookups
+//   - the AS name search
 package server
 
 import (