fix go-gitea#4479: add fuzzy keyword search to title

models/fixtures/access.yml

@@ -171,3 +171,9 @@
   user_id: 40
   repo_id: 61
   mode: 4
+
+-
+  id: 30
+  user_id: 40
+  repo_id: 62
+  mode: 4

models/fixtures/issue.yml

@@ -346,7 +346,7 @@
   poster_id: 39
   original_author_id: 0
   name: repo60 pull1
-  content: content for the 1st issue
+  content: content for the 1st pr
   milestone_id: 0
   priority: 0
   is_closed: false
@@ -360,10 +360,112 @@
   id: 22
   repo_id: 61
   index: 1
-  poster_id: 40
+  poster_id: 39
   original_author_id: 0
   name: repo61 pull1
-  content: content for the 1st issue
+  content: content for the 1st pr
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: true
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 23
+  repo_id: 62
+  index: 1
+  poster_id: 40
+  original_author_id: 0
+  name: Ökononmie der UI
+  content: die ökonomie der UI muß dringend verbessert werden
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: false
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 24
+  repo_id: 62
+  index: 2
+  poster_id: 40
+  original_author_id: 0
+  name: 갃갃갃
+  content: 啊啊啊
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: false
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 25
+  repo_id: 62
+  index: 3
+  poster_id: 40
+  original_author_id: 0
+  name: 啊啊啊
+  content: 갃갃갃
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: false
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 26
+  repo_id: 62
+  index: 4
+  poster_id: 40
+  original_author_id: 0
+  name: repo62 pull1 - Ökononmie der UI
+  content: die ökonomie der UI muß dringend verbessert werden
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: true
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 27
+  repo_id: 62
+  index: 5
+  poster_id: 40
+  original_author_id: 0
+  name: repo62 pull2 - 갃갃갃
+  content: 啊啊啊
+  milestone_id: 0
+  priority: 0
+  is_closed: false
+  is_pull: true
+  num_comments: 0
+  created_unix: 1707270422
+  updated_unix: 1707270422
+  is_locked: false
+
+-
+  id: 28
+  repo_id: 62
+  index: 6
+  poster_id: 40
+  original_author_id: 0
+  name: repo62 pull3 - 啊啊啊
+  content: 갃갃갃
   milestone_id: 0
   priority: 0
   is_closed: false

models/fixtures/issue_index.yml

@@ -33,3 +33,7 @@
 -
   group_id: 51
   max_index: 1
+
+-
+  group_id: 62
+  max_index: 6

models/fixtures/repository.yml

@@ -1768,3 +1768,34 @@
   size: 0
   is_fsck_enabled: true
   close_issues_via_commit_in_any_branch: false
+
+-
+  id: 62
+  owner_id: 41
+  owner_name: org41
+  lower_name: repo62
+  name: repo62
+  default_branch: main
+  num_watches: 0
+  num_stars: 0
+  num_forks: 0
+  num_issues: 3
+  num_closed_issues: 0
+  num_pulls: 3
+  num_closed_pulls: 0
+  num_milestones: 0
+  num_closed_milestones: 0
+  num_projects: 0
+  num_closed_projects: 0
+  is_private: false
+  is_empty: false
+  is_archived: false
+  is_mirror: false
+  status: 0
+  is_fork: false
+  fork_id: 0
+  is_template: false
+  template_id: 0
+  size: 0
+  is_fsck_enabled: true
+  close_issues_via_commit_in_any_branch: false

models/fixtures/user.yml

@@ -1510,7 +1510,7 @@
   num_followers: 0
   num_following: 0
   num_stars: 0
-  num_repos: 1
+  num_repos: 2
   num_teams: 2
   num_members: 3
   visibility: 0

models/issues/issue_test.go

@@ -379,7 +379,7 @@ func TestCountIssues(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 	count, err := issues_model.CountIssues(db.DefaultContext, &issues_model.IssuesOptions{})
 	assert.NoError(t, err)
-	assert.EqualValues(t, 22, count)
+	assert.EqualValues(t, 25, count)
 }
 
 func TestIssueLoadAttributes(t *testing.T) {

models/repo/repo_list_test.go

@@ -138,12 +138,12 @@ func getTestCases() []struct {
 		{
 			name:  "AllPublic/PublicRepositoriesOfUserIncludingCollaborative",
 			opts:  &repo_model.SearchRepoOptions{ListOptions: db.ListOptions{Page: 1, PageSize: 10}, OwnerID: 15, AllPublic: true, Template: optional.Some(false)},
-			count: 33,
+			count: 34,
 		},
 		{
 			name:  "AllPublic/PublicAndPrivateRepositoriesOfUserIncludingCollaborative",
 			opts:  &repo_model.SearchRepoOptions{ListOptions: db.ListOptions{Page: 1, PageSize: 10}, OwnerID: 15, Private: true, AllPublic: true, AllLimited: true, Template: optional.Some(false)},
-			count: 38,
+			count: 39,
 		},
 		{
 			name:  "AllPublic/PublicAndPrivateRepositoriesOfUserIncludingCollaborativeByName",
@@ -158,7 +158,7 @@ func getTestCases() []struct {
 		{
 			name:  "AllPublic/PublicRepositoriesOfOrganization",
 			opts:  &repo_model.SearchRepoOptions{ListOptions: db.ListOptions{Page: 1, PageSize: 10}, OwnerID: 17, AllPublic: true, Collaborate: optional.Some(false), Template: optional.Some(false)},
-			count: 33,
+			count: 34,
 		},
 		{
 			name:  "AllTemplates",

modules/indexer/internal/bleve/query.go

@@ -28,6 +28,14 @@ func MatchPhraseQuery(matchPhrase, field, analyzer string, fuzziness int) *query
 	return q
 }
 
+// FuzzyQuery generates a fuzzy query for the given phrase, field, and fuzziness
+func FuzzyQuery(matchPhrase, field string, fuzziness int) *query.FuzzyQuery {
+	q := bleve.NewFuzzyQuery(matchPhrase)
+	q.FieldVal = field
+	q.Fuzziness = fuzziness
+	return q
+}
+
 // BoolFieldQuery generates a bool field query for the given value and field
 func BoolFieldQuery(value bool, field string) *query.BoolFieldQuery {
 	q := bleve.NewBoolFieldQuery(value)

modules/indexer/internal/bleve/util.go

@@ -50,12 +50,14 @@ func openIndexer(path string, latestVersion int) (bleve.Index, int, error) {
 
 func GuessFuzzinessByKeyword(s string) int {
 	// according to https://github.com/blevesearch/bleve/issues/1563, the supported max fuzziness is 2
-	// magic number 4 was chosen to determine the levenshtein distance per each character of a keyword
-	// BUT, when using CJK (eg: `갃갃갃` `啊啊啊`), it mismatches a lot.
+	// BUT, when using CJK (eg: `갃갃갃` `啊啊啊`), it mismatches a lot
+	// which we need to live with, as we need to support not just ASCII
+	// in case of code points >= 128 we will increase the fuzziness to 2
+	// the standard is 1
 	for _, r := range s {
 		if r >= 128 {
-			return 0
+			return 2
 		}
 	}
-	return min(2, len(s)/4)
+	return 1
 }

modules/indexer/issues/bleve/bleve.go

@@ -162,7 +162,7 @@ func (b *Indexer) Search(ctx context.Context, options *internal.SearchOptions) (
 		}
 
 		queries = append(queries, bleve.NewDisjunctionQuery([]query.Query{
-			inner_bleve.MatchPhraseQuery(options.Keyword, "title", issueIndexerAnalyzer, fuzziness),
+			inner_bleve.FuzzyQuery(options.Keyword, "title", fuzziness),
 			inner_bleve.MatchPhraseQuery(options.Keyword, "content", issueIndexerAnalyzer, fuzziness),
 			inner_bleve.MatchPhraseQuery(options.Keyword, "comments", issueIndexerAnalyzer, fuzziness),
 		}...))

routers/web/repo/issue.go

@@ -2677,6 +2677,7 @@ func SearchIssues(ctx *context.Context) {
 		MilestoneIDs:        includedMilestones,
 		ProjectID:           projectID,
 		SortBy:              issue_indexer.SortByCreatedDesc,
+		IsFuzzyKeyword:      true,
 	}
 
 	if since != 0 {