Add "result at the end" test, let the fulltext determine which words to

highlight

internal/fulltext/bleve.go

@@ -18,6 +18,7 @@
 package fulltext
 
 import (
+	"regexp"
 	"strings"
 
 	"github.com/blevesearch/bleve/v2"
@@ -60,6 +61,7 @@ type Indexer interface {
 	Index(elements ...IndexElement) error
 	Delete(eventID string) error
 	Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (*bleve.SearchResult, error)
+	GetHighlights(result *bleve.SearchResult) []string
 	Close() error
 }
 
@@ -124,6 +126,47 @@ func (f *Search) Delete(eventID string) error {
 	return f.FulltextIndex.Delete(eventID)
 }
 
+var highlightMatcher = regexp.MustCompile("<mark>(.*?)</mark>")
+
+// GetHighlights extracts the highlights from a SearchResult.
+func (f *Search) GetHighlights(result *bleve.SearchResult) []string {
+	if result == nil {
+		return []string{}
+	}
+
+	seenMatches := make(map[string]struct{})
+
+	for _, hit := range result.Hits {
+		if hit.Fragments == nil {
+			continue
+		}
+		fragments, ok := hit.Fragments["Content"]
+		if !ok {
+			continue
+		}
+		for _, x := range fragments {
+			substringMatches := highlightMatcher.FindAllStringSubmatch(x, -1)
+			for _, matches := range substringMatches {
+				for i := range matches {
+					if i == 0 { // skip first match, this is the complete substring match
+						continue
+					}
+					if _, ok := seenMatches[matches[i]]; ok {
+						continue
+					}
+					seenMatches[matches[i]] = struct{}{}
+				}
+			}
+		}
+	}
+
+	res := make([]string, 0, len(seenMatches))
+	for m := range seenMatches {
+		res = append(res, m)
+	}
+	return res
+}
+
 // Search searches the index given a search term, roomIDs and keys.
 func (f *Search) Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (*bleve.SearchResult, error) {
 	qry := bleve.NewConjunctionQuery()
@@ -163,6 +206,10 @@ func (f *Search) Search(term string, roomIDs, keys []string, limit, from int, or
 		s.SortBy([]string{"-StreamPosition"})
 	}
 
+	// Highlight some words
+	s.Highlight = bleve.NewHighlight()
+	s.Highlight.Fields = []string{"Content"}
+
 	return f.FulltextIndex.Search(s)
 }
 

internal/fulltext/bleve_test.go

@@ -164,10 +164,12 @@ func TestSearch(t *testing.T) {
 		args           args
 		wantCount      int
 		wantErr        bool
+		wantHighlights []string
 	}{
 		{
 			name:           "Can search for many results in one room",
 			wantCount:      16,
+			wantHighlights: []string{"lorem"},
 			args: args{
 				term:      "lorem",
 				roomIndex: []int{0},
@@ -177,6 +179,7 @@ func TestSearch(t *testing.T) {
 		{
 			name:           "Can search for one result in one room",
 			wantCount:      1,
+			wantHighlights: []string{"lorem"},
 			args: args{
 				term:      "lorem",
 				roomIndex: []int{16},
@@ -186,6 +189,7 @@ func TestSearch(t *testing.T) {
 		{
 			name:           "Can search for many results in multiple rooms",
 			wantCount:      17,
+			wantHighlights: []string{"lorem"},
 			args: args{
 				term:      "lorem",
 				roomIndex: []int{0, 16},
@@ -195,6 +199,7 @@ func TestSearch(t *testing.T) {
 		{
 			name:           "Can search for many results in all rooms, reversed",
 			wantCount:      30,
+			wantHighlights: []string{"lorem"},
 			args: args{
 				term:             "lorem",
 				limit:            30,
@@ -204,6 +209,7 @@ func TestSearch(t *testing.T) {
 		{
 			name:           "Can search for specific search room name",
 			wantCount:      1,
+			wantHighlights: []string{"testing"},
 			args: args{
 				term:      "testing",
 				roomIndex: []int{},
@@ -214,6 +220,7 @@ func TestSearch(t *testing.T) {
 		{
 			name:           "Can search for specific search room topic",
 			wantCount:      1,
+			wantHighlights: []string{"fulltext"},
 			args: args{
 				term:      "fulltext",
 				roomIndex: []int{},
@@ -222,6 +229,7 @@ func TestSearch(t *testing.T) {
 			},
 		},
 	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			f, ctx := mustOpenIndex(t, "")
@@ -238,6 +246,12 @@ func TestSearch(t *testing.T) {
 				t.Errorf("Search() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
+
+			highlights := f.GetHighlights(got)
+			if !reflect.DeepEqual(highlights, tt.wantHighlights) {
+				t.Errorf("Search() got highligts = %v, want %v", highlights, tt.wantHighlights)
+			}
+
 			if !reflect.DeepEqual(len(got.Hits), tt.wantCount) {
 				t.Errorf("Search() got = %v, want %v", len(got.Hits), tt.wantCount)
 			}

internal/fulltext/bleve_wasm.go

@@ -33,6 +33,7 @@ type Indexer interface {
 	Index(elements ...IndexElement) error
 	Delete(eventID string) error
 	Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (SearchResult, error)
+	GetHighlights(result SearchResult) []string
 	Close() error
 }
 
@@ -71,3 +72,7 @@ func (f *Search) Delete(eventID string) error {
 func (f *Search) Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (SearchResult, error) {
 	return SearchResult{}, nil
 }
+
+func (f *Search) GetHighlights(result SearchResult) []string {
+	return []string{}
+}

syncapi/routing/search.go

@@ -19,7 +19,6 @@ import (
 	"net/http"
 	"sort"
 	"strconv"
-	"strings"
 	"time"
 
 	"github.com/blevesearch/bleve/v2/search"
@@ -243,7 +242,7 @@ func Search(req *http.Request, device *api.Device, syncDB storage.Database, fts
 				Groups:     Groups{RoomID: groups},
 				Results:    results,
 				NextBatch:  nextBatchResult,
-				Highlights: strings.Split(searchReq.SearchCategories.RoomEvents.SearchTerm, " "),
+				Highlights: fts.GetHighlights(result),
 				State:      stateForRooms,
 			},
 		},

syncapi/routing/search_test.go

@@ -53,7 +53,7 @@ func TestSearch(t *testing.T) {
 			device:    &aliceDevice,
 		},
 		{
-			name:   "searchTerm specified",
+			name:   "searchTerm specified, found at the beginning",
 			wantOK: true,
 			searchReq: SearchRequest{
 				SearchCategories: SearchCategories{RoomEvents: RoomEvents{SearchTerm: "hello"}},
@@ -61,6 +61,26 @@ func TestSearch(t *testing.T) {
 			device:            &aliceDevice,
 			wantResponseCount: 1,
 		},
+		{
+			name:   "searchTerm specified, found at the end",
+			wantOK: true,
+			searchReq: SearchRequest{
+				SearchCategories: SearchCategories{RoomEvents: RoomEvents{SearchTerm: "world3"}},
+			},
+			device:            &aliceDevice,
+			wantResponseCount: 1,
+		},
+		/* the following would need matchQuery.SetFuzziness(1) in bleve.go
+		{
+			name:   "searchTerm fuzzy search",
+			wantOK: true,
+			searchReq: SearchRequest{
+				SearchCategories: SearchCategories{RoomEvents: RoomEvents{SearchTerm: "hell"}}, // this still should find hello world
+			},
+			device:            &aliceDevice,
+			wantResponseCount: 1,
+		},
+		*/
 		{
 			name:   "searchTerm specified but no result",
 			wantOK: true,