3 files changed, 963 insertions, 0 deletions

diff --git a/modules/indexer/issues/internal/indexer.go b/modules/indexer/issues/internal/indexer.go
new file mode 100644
index 00000000..95740bc5
--- /dev/null
+++ b/modules/indexer/issues/internal/indexer.go
@@ -0,0 +1,42 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package internal
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/modules/indexer/internal"
+)
+
+// Indexer defines an interface to indexer issues contents
+type Indexer interface {
+	internal.Indexer
+	Index(ctx context.Context, issue ...*IndexerData) error
+	Delete(ctx context.Context, ids ...int64) error
+	Search(ctx context.Context, options *SearchOptions) (*SearchResult, error)
+}
+
+// NewDummyIndexer returns a dummy indexer
+func NewDummyIndexer() Indexer {
+	return &dummyIndexer{
+		Indexer: internal.NewDummyIndexer(),
+	}
+}
+
+type dummyIndexer struct {
+	internal.Indexer
+}
+
+func (d *dummyIndexer) Index(_ context.Context, _ ...*IndexerData) error {
+	return fmt.Errorf("indexer is not ready")
+}
+
+func (d *dummyIndexer) Delete(_ context.Context, _ ...int64) error {
+	return fmt.Errorf("indexer is not ready")
+}
+
+func (d *dummyIndexer) Search(_ context.Context, _ *SearchOptions) (*SearchResult, error) {
+	return nil, fmt.Errorf("indexer is not ready")
+}
diff --git a/modules/indexer/issues/internal/model.go b/modules/indexer/issues/internal/model.go
new file mode 100644
index 00000000..2dfee8b7
--- /dev/null
+++ b/modules/indexer/issues/internal/model.go
@@ -0,0 +1,150 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package internal
+
+import (
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+// IndexerData data stored in the issue indexer
+type IndexerData struct {
+	ID       int64 `json:"id"`
+	RepoID   int64 `json:"repo_id"`
+	IsPublic bool  `json:"is_public"` // If the repo is public
+
+	// Fields used for keyword searching
+	Title    string   `json:"title"`
+	Content  string   `json:"content"`
+	Comments []string `json:"comments"`
+
+	// Fields used for filtering
+	IsPull             bool               `json:"is_pull"`
+	IsClosed           bool               `json:"is_closed"`
+	LabelIDs           []int64            `json:"label_ids"`
+	NoLabel            bool               `json:"no_label"` // True if LabelIDs is empty
+	MilestoneID        int64              `json:"milestone_id"`
+	ProjectID          int64              `json:"project_id"`
+	ProjectColumnID    int64              `json:"project_board_id"` // the key should be kept as project_board_id to keep compatible
+	PosterID           int64              `json:"poster_id"`
+	AssigneeID         int64              `json:"assignee_id"`
+	MentionIDs         []int64            `json:"mention_ids"`
+	ReviewedIDs        []int64            `json:"reviewed_ids"`
+	ReviewRequestedIDs []int64            `json:"review_requested_ids"`
+	SubscriberIDs      []int64            `json:"subscriber_ids"`
+	UpdatedUnix        timeutil.TimeStamp `json:"updated_unix"`
+
+	// Fields used for sorting
+	// UpdatedUnix is both used for filtering and sorting.
+	// ID is used for sorting too, to make the sorting stable.
+	CreatedUnix  timeutil.TimeStamp `json:"created_unix"`
+	DeadlineUnix timeutil.TimeStamp `json:"deadline_unix"`
+	CommentCount int64              `json:"comment_count"`
+}
+
+// Match represents on search result
+type Match struct {
+	ID    int64   `json:"id"`
+	Score float64 `json:"score"`
+}
+
+// SearchResult represents search results
+type SearchResult struct {
+	Total int64
+	Hits  []Match
+}
+
+// SearchOptions represents search options.
+//
+// It has a slightly different design from database query options.
+// In database query options, a field is never a pointer, so it could be confusing when it's zero value:
+// Do you want to find data with a field value of 0, or do you not specify the field in the options?
+// To avoid this confusion, db introduced db.NoConditionID(-1).
+// So zero value means the field is not specified in the search options, and db.NoConditionID means "== 0" or "id NOT IN (SELECT id FROM ...)"
+// It's still not ideal, it trapped developers many times.
+// And sometimes -1 could be a valid value, like issue ID, negative numbers indicate exclusion.
+// Since db.NoConditionID is for "db" (the package name is db), it makes sense not to use it in the indexer:
+// Why do bleve/elasticsearch/meilisearch indexers need to know about db.NoConditionID?
+// So in SearchOptions, we use pointer for fields which could be not specified,
+// and always use the value to filter if it's not nil, even if it's zero or negative.
+// It can handle almost all cases, if there is an exception, we can add a new field, like NoLabelOnly.
+// Unfortunately, we still use db for the indexer and have to convert between db.NoConditionID and nil for legacy reasons.
+type SearchOptions struct {
+	Keyword string // keyword to search
+
+	IsFuzzyKeyword bool // if false the levenshtein distance is 0
+
+	RepoIDs   []int64 // repository IDs which the issues belong to
+	AllPublic bool    // if include all public repositories
+
+	IsPull   optional.Option[bool] // if the issues is a pull request
+	IsClosed optional.Option[bool] // if the issues is closed
+
+	IncludedLabelIDs    []int64 // labels the issues have
+	ExcludedLabelIDs    []int64 // labels the issues don't have
+	IncludedAnyLabelIDs []int64 // labels the issues have at least one. It will be ignored if IncludedLabelIDs is not empty. It's an uncommon filter, but it has been supported accidentally by issues.IssuesOptions.IncludedLabelNames.
+	NoLabelOnly         bool    // if the issues have no label, if true, IncludedLabelIDs and ExcludedLabelIDs, IncludedAnyLabelIDs will be ignored
+
+	MilestoneIDs []int64 // milestones the issues have
+
+	ProjectID       optional.Option[int64] // project the issues belong to
+	ProjectColumnID optional.Option[int64] // project column the issues belong to
+
+	PosterID optional.Option[int64] // poster of the issues
+
+	AssigneeID optional.Option[int64] // assignee of the issues, zero means no assignee
+
+	MentionID optional.Option[int64] // mentioned user of the issues
+
+	ReviewedID        optional.Option[int64] // reviewer of the issues
+	ReviewRequestedID optional.Option[int64] // requested reviewer of the issues
+
+	SubscriberID optional.Option[int64] // subscriber of the issues
+
+	UpdatedAfterUnix  optional.Option[int64]
+	UpdatedBeforeUnix optional.Option[int64]
+
+	Paginator *db.ListOptions
+
+	SortBy SortBy // sort by field
+}
+
+// Copy returns a copy of the options.
+// Be careful, it's not a deep copy, so `SearchOptions.RepoIDs = {...}` is OK while `SearchOptions.RepoIDs[0] = ...` is not.
+func (o *SearchOptions) Copy(edit ...func(options *SearchOptions)) *SearchOptions {
+	if o == nil {
+		return nil
+	}
+	v := *o
+	for _, e := range edit {
+		e(&v)
+	}
+	return &v
+}
+
+type SortBy string
+
+const (
+	SortByCreatedDesc  SortBy = "-created_unix"
+	SortByUpdatedDesc  SortBy = "-updated_unix"
+	SortByCommentsDesc SortBy = "-comment_count"
+	SortByDeadlineDesc SortBy = "-deadline_unix"
+	SortByCreatedAsc   SortBy = "created_unix"
+	SortByUpdatedAsc   SortBy = "updated_unix"
+	SortByCommentsAsc  SortBy = "comment_count"
+	SortByDeadlineAsc  SortBy = "deadline_unix"
+	// Unsupported sort types which are supported by issues.IssuesOptions.SortType:
+	//
+	//  - "priorityrepo":
+	//                    It's impossible to support it in the indexer.
+	//                    It is based on the specified repository in the request, so we cannot add static field to the indexer.
+	//                    If we do something like that query the issues in the specified repository first then append other issues,
+	//                    it will break the pagination.
+	//
+	// - "project-column-sorting":
+	//                    Although it's possible to support it by adding project.ProjectIssue.Sorting to the indexer,
+	//                    but what if the issue belongs to multiple projects?
+	//                    Since it's unsupported to search issues with keyword in project page, we don't need to support it.
+)
diff --git a/modules/indexer/issues/internal/tests/tests.go b/modules/indexer/issues/internal/tests/tests.go
new file mode 100644
index 00000000..a93b2913
--- /dev/null
+++ b/modules/indexer/issues/internal/tests/tests.go
@@ -0,0 +1,771 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// This package contains tests for issues indexer modules.
+// All the code in this package is only used for testing.
+// Do not put any production code in this package to avoid it being included in the final binary.
+
+package tests
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"testing"
+	"time"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/indexer/issues/internal"
+	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIndexer(t *testing.T, indexer internal.Indexer) {
+	_, err := indexer.Init(context.Background())
+	require.NoError(t, err)
+
+	require.NoError(t, indexer.Ping(context.Background()))
+
+	var (
+		ids  []int64
+		data = map[int64]*internal.IndexerData{}
+	)
+	{
+		d := generateDefaultIndexerData()
+		for _, v := range d {
+			ids = append(ids, v.ID)
+			data[v.ID] = v
+		}
+		require.NoError(t, indexer.Index(context.Background(), d...))
+		require.NoError(t, waitData(indexer, int64(len(data))))
+	}
+
+	defer func() {
+		require.NoError(t, indexer.Delete(context.Background(), ids...))
+	}()
+
+	for _, c := range cases {
+		t.Run(c.Name, func(t *testing.T) {
+			if len(c.ExtraData) > 0 {
+				require.NoError(t, indexer.Index(context.Background(), c.ExtraData...))
+				for _, v := range c.ExtraData {
+					data[v.ID] = v
+				}
+				require.NoError(t, waitData(indexer, int64(len(data))))
+				defer func() {
+					for _, v := range c.ExtraData {
+						require.NoError(t, indexer.Delete(context.Background(), v.ID))
+						delete(data, v.ID)
+					}
+					require.NoError(t, waitData(indexer, int64(len(data))))
+				}()
+			}
+
+			result, err := indexer.Search(context.Background(), c.SearchOptions)
+			require.NoError(t, err)
+
+			if c.Expected != nil {
+				c.Expected(t, data, result)
+			} else {
+				ids := make([]int64, 0, len(result.Hits))
+				for _, hit := range result.Hits {
+					ids = append(ids, hit.ID)
+				}
+				assert.Equal(t, c.ExpectedIDs, ids)
+				assert.Equal(t, c.ExpectedTotal, result.Total)
+			}
+
+			// test counting
+			c.SearchOptions.Paginator = &db.ListOptions{PageSize: 0}
+			countResult, err := indexer.Search(context.Background(), c.SearchOptions)
+			require.NoError(t, err)
+			assert.Empty(t, countResult.Hits)
+			assert.Equal(t, result.Total, countResult.Total)
+		})
+	}
+}
+
+var cases = []*testIndexerCase{
+	{
+		Name:          "default",
+		SearchOptions: &internal.SearchOptions{},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+		},
+	},
+	{
+		Name: "empty",
+		SearchOptions: &internal.SearchOptions{
+			Keyword: "f1dfac73-fda6-4a6b-b8a4-2408fcb8ef69",
+		},
+		ExpectedIDs:   []int64{},
+		ExpectedTotal: 0,
+	},
+	{
+		Name: "with limit",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			assert.Equal(t, len(data), int(result.Total))
+		},
+	},
+	{
+		Name: "Keyword",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1000, Title: "hi hello world"},
+			{ID: 1001, Content: "hi hello world"},
+			{ID: 1002, Comments: []string{"hi", "hello world"}},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword: "hello",
+		},
+		ExpectedIDs:   []int64{1002, 1001, 1000},
+		ExpectedTotal: 3,
+	},
+	{
+		Name: "Keyword Fuzzy",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1000, Title: "hi hello world"},
+			{ID: 1001, Content: "hi hello world"},
+			{ID: 1002, Comments: []string{"hi", "hello world"}},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword:        "hello world",
+			IsFuzzyKeyword: true,
+		},
+		ExpectedIDs:   []int64{1002, 1001, 1000},
+		ExpectedTotal: 3,
+	},
+	{
+		Name: "RepoIDs",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1001, Title: "hello world", RepoID: 1, IsPublic: false},
+			{ID: 1002, Title: "hello world", RepoID: 1, IsPublic: false},
+			{ID: 1003, Title: "hello world", RepoID: 2, IsPublic: true},
+			{ID: 1004, Title: "hello world", RepoID: 2, IsPublic: true},
+			{ID: 1005, Title: "hello world", RepoID: 3, IsPublic: true},
+			{ID: 1006, Title: "hello world", RepoID: 4, IsPublic: false},
+			{ID: 1007, Title: "hello world", RepoID: 5, IsPublic: false},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword: "hello",
+			RepoIDs: []int64{1, 4},
+		},
+		ExpectedIDs:   []int64{1006, 1002, 1001},
+		ExpectedTotal: 3,
+	},
+	{
+		Name: "RepoIDs and AllPublic",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1001, Title: "hello world", RepoID: 1, IsPublic: false},
+			{ID: 1002, Title: "hello world", RepoID: 1, IsPublic: false},
+			{ID: 1003, Title: "hello world", RepoID: 2, IsPublic: true},
+			{ID: 1004, Title: "hello world", RepoID: 2, IsPublic: true},
+			{ID: 1005, Title: "hello world", RepoID: 3, IsPublic: true},
+			{ID: 1006, Title: "hello world", RepoID: 4, IsPublic: false},
+			{ID: 1007, Title: "hello world", RepoID: 5, IsPublic: false},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword:   "hello",
+			RepoIDs:   []int64{1, 4},
+			AllPublic: true,
+		},
+		ExpectedIDs:   []int64{1006, 1005, 1004, 1003, 1002, 1001},
+		ExpectedTotal: 6,
+	},
+	{
+		Name: "issue only",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			IsPull: optional.Some(false),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.False(t, data[v.ID].IsPull)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool { return !v.IsPull }), result.Total)
+		},
+	},
+	{
+		Name: "pull only",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			IsPull: optional.Some(true),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.True(t, data[v.ID].IsPull)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool { return v.IsPull }), result.Total)
+		},
+	},
+	{
+		Name: "opened only",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			IsClosed: optional.Some(false),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.False(t, data[v.ID].IsClosed)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool { return !v.IsClosed }), result.Total)
+		},
+	},
+	{
+		Name: "closed only",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			IsClosed: optional.Some(true),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.True(t, data[v.ID].IsClosed)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool { return v.IsClosed }), result.Total)
+		},
+	},
+	{
+		Name: "labels",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1000, Title: "hello a", LabelIDs: []int64{2000, 2001, 2002}},
+			{ID: 1001, Title: "hello b", LabelIDs: []int64{2000, 2001}},
+			{ID: 1002, Title: "hello c", LabelIDs: []int64{2000, 2001, 2003}},
+			{ID: 1003, Title: "hello d", LabelIDs: []int64{2000}},
+			{ID: 1004, Title: "hello e", LabelIDs: []int64{}},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword:          "hello",
+			IncludedLabelIDs: []int64{2000, 2001},
+			ExcludedLabelIDs: []int64{2003},
+		},
+		ExpectedIDs:   []int64{1001, 1000},
+		ExpectedTotal: 2,
+	},
+	{
+		Name: "include any labels",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1000, Title: "hello a", LabelIDs: []int64{2000, 2001, 2002}},
+			{ID: 1001, Title: "hello b", LabelIDs: []int64{2001}},
+			{ID: 1002, Title: "hello c", LabelIDs: []int64{2000, 2001, 2003}},
+			{ID: 1003, Title: "hello d", LabelIDs: []int64{2002}},
+			{ID: 1004, Title: "hello e", LabelIDs: []int64{}},
+		},
+		SearchOptions: &internal.SearchOptions{
+			Keyword:             "hello",
+			IncludedAnyLabelIDs: []int64{2001, 2002},
+			ExcludedLabelIDs:    []int64{2003},
+		},
+		ExpectedIDs:   []int64{1003, 1001, 1000},
+		ExpectedTotal: 3,
+	},
+	{
+		Name: "MilestoneIDs",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			MilestoneIDs: []int64{1, 2, 6},
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Contains(t, []int64{1, 2, 6}, data[v.ID].MilestoneID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.MilestoneID == 1 || v.MilestoneID == 2 || v.MilestoneID == 6
+			}), result.Total)
+		},
+	},
+	{
+		Name: "no MilestoneIDs",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			MilestoneIDs: []int64{0},
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(0), data[v.ID].MilestoneID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.MilestoneID == 0
+			}), result.Total)
+		},
+	},
+	{
+		Name: "ProjectID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ProjectID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(1), data[v.ID].ProjectID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.ProjectID == 1
+			}), result.Total)
+		},
+	},
+	{
+		Name: "no ProjectID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ProjectID: optional.Some(int64(0)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(0), data[v.ID].ProjectID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.ProjectID == 0
+			}), result.Total)
+		},
+	},
+	{
+		Name: "ProjectColumnID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ProjectColumnID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(1), data[v.ID].ProjectColumnID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.ProjectColumnID == 1
+			}), result.Total)
+		},
+	},
+	{
+		Name: "no ProjectColumnID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ProjectColumnID: optional.Some(int64(0)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(0), data[v.ID].ProjectColumnID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.ProjectColumnID == 0
+			}), result.Total)
+		},
+	},
+	{
+		Name: "PosterID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			PosterID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(1), data[v.ID].PosterID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.PosterID == 1
+			}), result.Total)
+		},
+	},
+	{
+		Name: "AssigneeID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			AssigneeID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(1), data[v.ID].AssigneeID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.AssigneeID == 1
+			}), result.Total)
+		},
+	},
+	{
+		Name: "no AssigneeID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			AssigneeID: optional.Some(int64(0)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Equal(t, int64(0), data[v.ID].AssigneeID)
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return v.AssigneeID == 0
+			}), result.Total)
+		},
+	},
+	{
+		Name: "MentionID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			MentionID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Contains(t, data[v.ID].MentionIDs, int64(1))
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return slices.Contains(v.MentionIDs, 1)
+			}), result.Total)
+		},
+	},
+	{
+		Name: "ReviewedID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ReviewedID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Contains(t, data[v.ID].ReviewedIDs, int64(1))
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return slices.Contains(v.ReviewedIDs, 1)
+			}), result.Total)
+		},
+	},
+	{
+		Name: "ReviewRequestedID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			ReviewRequestedID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Contains(t, data[v.ID].ReviewRequestedIDs, int64(1))
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return slices.Contains(v.ReviewRequestedIDs, 1)
+			}), result.Total)
+		},
+	},
+	{
+		Name: "SubscriberID",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			SubscriberID: optional.Some(int64(1)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.Contains(t, data[v.ID].SubscriberIDs, int64(1))
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return slices.Contains(v.SubscriberIDs, 1)
+			}), result.Total)
+		},
+	},
+	{
+		Name: "updated",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 5,
+			},
+			UpdatedAfterUnix:  optional.Some(int64(20)),
+			UpdatedBeforeUnix: optional.Some(int64(30)),
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Len(t, result.Hits, 5)
+			for _, v := range result.Hits {
+				assert.GreaterOrEqual(t, data[v.ID].UpdatedUnix, int64(20))
+				assert.LessOrEqual(t, data[v.ID].UpdatedUnix, int64(30))
+			}
+			assert.Equal(t, countIndexerData(data, func(v *internal.IndexerData) bool {
+				return data[v.ID].UpdatedUnix >= 20 && data[v.ID].UpdatedUnix <= 30
+			}), result.Total)
+		},
+	},
+	{
+		Name: "SortByCreatedDesc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByCreatedDesc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.GreaterOrEqual(t, data[v.ID].CreatedUnix, data[result.Hits[i+1].ID].CreatedUnix)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByUpdatedDesc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByUpdatedDesc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.GreaterOrEqual(t, data[v.ID].UpdatedUnix, data[result.Hits[i+1].ID].UpdatedUnix)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByCommentsDesc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByCommentsDesc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.GreaterOrEqual(t, data[v.ID].CommentCount, data[result.Hits[i+1].ID].CommentCount)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByDeadlineDesc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByDeadlineDesc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.GreaterOrEqual(t, data[v.ID].DeadlineUnix, data[result.Hits[i+1].ID].DeadlineUnix)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByCreatedAsc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByCreatedAsc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.LessOrEqual(t, data[v.ID].CreatedUnix, data[result.Hits[i+1].ID].CreatedUnix)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByUpdatedAsc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByUpdatedAsc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.LessOrEqual(t, data[v.ID].UpdatedUnix, data[result.Hits[i+1].ID].UpdatedUnix)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByCommentsAsc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByCommentsAsc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.LessOrEqual(t, data[v.ID].CommentCount, data[result.Hits[i+1].ID].CommentCount)
+				}
+			}
+		},
+	},
+	{
+		Name: "SortByDeadlineAsc",
+		SearchOptions: &internal.SearchOptions{
+			Paginator: &db.ListOptionsAll,
+			SortBy:    internal.SortByDeadlineAsc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			assert.Equal(t, len(data), len(result.Hits))
+			assert.Equal(t, len(data), int(result.Total))
+			for i, v := range result.Hits {
+				if i < len(result.Hits)-1 {
+					assert.LessOrEqual(t, data[v.ID].DeadlineUnix, data[result.Hits[i+1].ID].DeadlineUnix)
+				}
+			}
+		},
+	},
+}
+
+type testIndexerCase struct {
+	Name      string
+	ExtraData []*internal.IndexerData
+
+	SearchOptions *internal.SearchOptions
+
+	Expected      func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) // if nil, use ExpectedIDs, ExpectedTotal
+	ExpectedIDs   []int64
+	ExpectedTotal int64
+}
+
+func generateDefaultIndexerData() []*internal.IndexerData {
+	var id int64
+	var data []*internal.IndexerData
+	for repoID := int64(1); repoID <= 10; repoID++ {
+		for issueIndex := int64(1); issueIndex <= 20; issueIndex++ {
+			id++
+
+			comments := make([]string, id%4)
+			for i := range comments {
+				comments[i] = fmt.Sprintf("comment%d", i)
+			}
+
+			labelIDs := make([]int64, id%5)
+			for i := range labelIDs {
+				labelIDs[i] = int64(i) + 1 // LabelID should not be 0
+			}
+			mentionIDs := make([]int64, id%6)
+			for i := range mentionIDs {
+				mentionIDs[i] = int64(i) + 1 // MentionID should not be 0
+			}
+			reviewedIDs := make([]int64, id%7)
+			for i := range reviewedIDs {
+				reviewedIDs[i] = int64(i) + 1 // ReviewID should not be 0
+			}
+			reviewRequestedIDs := make([]int64, id%8)
+			for i := range reviewRequestedIDs {
+				reviewRequestedIDs[i] = int64(i) + 1 // ReviewRequestedID should not be 0
+			}
+			subscriberIDs := make([]int64, id%9)
+			for i := range subscriberIDs {
+				subscriberIDs[i] = int64(i) + 1 // SubscriberID should not be 0
+			}
+
+			data = append(data, &internal.IndexerData{
+				ID:                 id,
+				RepoID:             repoID,
+				IsPublic:           repoID%2 == 0,
+				Title:              fmt.Sprintf("issue%d of repo%d", issueIndex, repoID),
+				Content:            fmt.Sprintf("content%d", issueIndex),
+				Comments:           comments,
+				IsPull:             issueIndex%2 == 0,
+				IsClosed:           issueIndex%3 == 0,
+				LabelIDs:           labelIDs,
+				NoLabel:            len(labelIDs) == 0,
+				MilestoneID:        issueIndex % 4,
+				ProjectID:          issueIndex % 5,
+				ProjectColumnID:    issueIndex % 6,
+				PosterID:           id%10 + 1, // PosterID should not be 0
+				AssigneeID:         issueIndex % 10,
+				MentionIDs:         mentionIDs,
+				ReviewedIDs:        reviewedIDs,
+				ReviewRequestedIDs: reviewRequestedIDs,
+				SubscriberIDs:      subscriberIDs,
+				UpdatedUnix:        timeutil.TimeStamp(id + issueIndex),
+				CreatedUnix:        timeutil.TimeStamp(id),
+				DeadlineUnix:       timeutil.TimeStamp(id + issueIndex + repoID),
+				CommentCount:       int64(len(comments)),
+			})
+		}
+	}
+
+	return data
+}
+
+func countIndexerData(data map[int64]*internal.IndexerData, f func(v *internal.IndexerData) bool) int64 {
+	var count int64
+	for _, v := range data {
+		if f(v) {
+			count++
+		}
+	}
+	return count
+}
+
+// waitData waits for the indexer to index all data.
+// Some engines like Elasticsearch index data asynchronously, so we need to wait for a while.
+func waitData(indexer internal.Indexer, total int64) error {
+	var actual int64
+	for i := 0; i < 100; i++ {
+		result, err := indexer.Search(context.Background(), &internal.SearchOptions{
+			Paginator: &db.ListOptions{
+				PageSize: 0,
+			},
+		})
+		if err != nil {
+			return err
+		}
+		actual = result.Total
+		if actual == total {
+			return nil
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+	return fmt.Errorf("waitData: expected %d, actual %d", total, actual)
+}