Fixed hashtag search for DB search (#23313)

* Fixed hashtag search for DB search

* Fixed typo

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/store/searchtest/post_layer.go

@@ -192,6 +192,11 @@ var searchPostStoreTests = []searchTest{
 		Fn:   testSearchHashtagWithUnderscores,
 		Tags: []string{EngineAll},
 	},
+	{
+		Name: "Should be able to search by hashtags with dashes and numbers",
+		Fn:   testSearchHashtagWithDashAndNumbers,
+		Tags: []string{EngineAll},
+	},
 	{
 		Name: "Should not return system messages",
 		Fn:   testSearchShouldExcludeSystemMessages,
@@ -1416,6 +1421,29 @@ func testSearchHashtagWithUnderscores(t *testing.T, th *SearchTestHelper) {
 	th.checkPostInSearchResults(t, p1.Id, results.Posts)
 }
 
+func testSearchHashtagWithDashAndNumbers(t *testing.T, th *SearchTestHelper) {
+	p1, err := th.createPost(th.User.Id, th.ChannelBasic.Id, "searching hashtag #hashtag-1-finals23", "#hashtag-1-finals23", model.PostTypeDefault, 0, false)
+	require.NoError(t, err)
+
+	p2, err := th.createPost(th.User.Id, th.ChannelBasic.Id, "searching hashtag #hashtag-1-finals23", "#hashtag-1-finals23", model.PostTypeDefault, 0, false)
+	require.NoError(t, err)
+
+	_, err = th.createPost(th.User.Id, th.ChannelBasic.Id, "searching hashtag #hashtag-finals20", "#hashtag-finals20", model.PostTypeDefault, 0, false)
+	require.NoError(t, err)
+	defer th.deleteUserPosts(th.User.Id)
+
+	params := &model.SearchParams{
+		Terms:     "#hashtag-1-finals23",
+		IsHashtag: true,
+	}
+	results, err := th.Store.Post().SearchPostsForUser([]*model.SearchParams{params}, th.User.Id, th.Team.Id, 0, 20)
+	require.NoError(t, err)
+
+	require.Len(t, results.Posts, 2)
+	th.checkPostInSearchResults(t, p1.Id, results.Posts)
+	th.checkPostInSearchResults(t, p2.Id, results.Posts)
+}
+
 func testSearchShouldExcludeSystemMessages(t *testing.T, th *SearchTestHelper) {
 	_, err := th.createPost(th.User.Id, th.ChannelBasic.Id, "test system message one", "", model.PostTypeJoinChannel, 0, false)
 	require.NoError(t, err)

server/channels/store/sqlstore/post_store.go

@@ -1982,7 +1982,9 @@ func (s *SqlPostStore) search(teamId string, userId string, params *model.Search
 	}
 
 	for _, c := range s.specialSearchChars() {
-		terms = strings.Replace(terms, c, " ", -1)
+		if !params.IsHashtag {
+			terms = strings.Replace(terms, c, " ", -1)
+		}
 		excludedTerms = strings.Replace(excludedTerms, c, " ", -1)
 	}
 
@@ -2007,7 +2009,12 @@ func (s *SqlPostStore) search(teamId string, userId string, params *model.Search
 		} else if strings.HasPrefix(terms, `"`) && strings.HasSuffix(terms, `"`) {
 			termsClause = "(" + strings.Join(strings.Fields(terms), " <-> ") + ")" + excludeClause
 		} else {
-			termsClause = "(" + strings.Join(strings.Fields(terms), " & ") + ")" + excludeClause
+			tsVectorSearchQuery := strings.Join(strings.Fields(terms), " & ")
+			if params.IsHashtag {
+				tsVectorSearchQuery = terms
+			}
+
+			termsClause = "(" + tsVectorSearchQuery + ")" + excludeClause
 		}
 
 		searchClause := fmt.Sprintf("to_tsvector('%[1]s', %[2]s) @@  to_tsquery('%[1]s', ?)", s.pgDefaultTextSearchConfig, searchType)
@@ -2041,6 +2048,11 @@ func (s *SqlPostStore) search(teamId string, userId string, params *model.Search
 		}
 
 		searchClause := fmt.Sprintf("MATCH (%s) AGAINST (? IN BOOLEAN MODE)", searchType)
+
+		if params.IsHashtag {
+			termsClause = "\"" + termsClause + "\""
+		}
+
 		baseQuery = baseQuery.Where(searchClause, termsClause)
 	}