enhance(project): filter project milestones by linked issues (#39958) (#39984)

Backport #39958 by @SHIVANSHGARG07

The project milestone filter listed every milestone of the repo, or of
all accessible org repos for org projects, including ones with no issue
in the project. That made the dropdown noisy and unhelpful.

Both repo and org projects now list only milestones that have at least
one issue linked to the project, via a new `ProjectID` option on
`FindMilestoneOptions`.

Fixes: https://github.com/go-gitea/gitea/issues/39150
Co-authored-by: Shivansh Garg <shivanshgarg587@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

models/issues/milestone_list.go

@@ -39,12 +39,13 @@ func (milestones MilestoneList) SplitByOpenClosed() (open, closed MilestoneList)
 // FindMilestoneOptions contain options to get milestones
 type FindMilestoneOptions struct {
 	db.ListOptions
-	RepoID   int64
-	IsClosed optional.Option[bool]
-	Name     string
-	SortType string
-	RepoCond builder.Cond
-	RepoIDs  []int64
+	RepoID    int64
+	IsClosed  optional.Option[bool]
+	Name      string
+	SortType  string
+	RepoCond  builder.Cond
+	RepoIDs   []int64
+	ProjectID int64
 }
 
 func (opts FindMilestoneOptions) ToConds() builder.Cond {
@@ -64,6 +65,11 @@ func (opts FindMilestoneOptions) ToConds() builder.Cond {
 	if len(opts.Name) != 0 {
 		cond = cond.And(db.BuildCaseInsensitiveLike("name", opts.Name))
 	}
+	if opts.ProjectID != 0 {
+		cond = cond.And(builder.In("id", builder.Select("issue.milestone_id").From("issue").
+			InnerJoin("project_issue", "project_issue.issue_id = issue.id").
+			Where(builder.Eq{"project_issue.project_id": opts.ProjectID})))
+	}
 
 	return cond
 }

routers/web/org/projects.go

@@ -438,7 +438,8 @@ func ViewProject(ctx *context.Context) {
 			accessCond,
 		)
 		milestones, err = db.Find[issues_model.Milestone](ctx, issues_model.FindMilestoneOptions{
-			RepoCond: repoCond,
+			RepoCond:  repoCond,
+			ProjectID: project.ID,
 		})
 		if err != nil {
 			ctx.ServerError("GetOrgMilestones", err)

routers/web/repo/issue_list.go

@@ -380,10 +380,11 @@ func prepareIssueFilterExclusiveOrderScopes(ctx *context.Context, allLabels []*i
 	ctx.Data["ExclusiveLabelScopes"] = scopes
 }
 
-func renderMilestones(ctx *context.Context) {
+func renderMilestones(ctx *context.Context, projectID int64) {
 	// Get milestones
 	milestones, err := db.Find[issues_model.Milestone](ctx, issues_model.FindMilestoneOptions{
-		RepoID: ctx.Repo.Repository.ID,
+		RepoID:    ctx.Repo.Repository.ID,
+		ProjectID: projectID,
 	})
 	if err != nil {
 		ctx.ServerError("GetAllRepoMilestones", err)
@@ -679,7 +680,7 @@ func Issues(ctx *context.Context) {
 		return
 	}
 
-	renderMilestones(ctx)
+	renderMilestones(ctx, 0)
 	if ctx.Written() {
 		return
 	}

routers/web/repo/projects.go

@@ -412,7 +412,7 @@ func ViewProject(ctx *context.Context) {
 	ctx.Data["Assignees"] = shared_user.MakeSelfOnTop(ctx.Doer, assigneeUsers)
 	ctx.Data["AssigneeID"] = assigneeID
 
-	renderMilestones(ctx)
+	renderMilestones(ctx, project.ID)
 	if ctx.Written() {
 		return
 	}

tests/integration/project_test.go

@@ -228,6 +228,12 @@ func getProjectIssueIDs(t *testing.T, htmlDoc *HTMLDoc) map[int64]struct{} {
 	return ids
 }
 
+func getProjectMilestoneNames(htmlDoc *HTMLDoc) []string {
+	return htmlDoc.Find(".list-header-filters a:has(.octicon-milestone)").Map(func(_ int, s *goquery.Selection) string {
+		return strings.TrimSpace(s.Text())
+	})
+}
+
 func TestRepoProjectFilterByMilestone(t *testing.T) {
 	// Project 1 is on repo 1 (user2/repo1) and has issues:
 	//   issue 1 (milestone_id=0), issue 2 (milestone_id=1), issue 3 (milestone_id=3), issue 5 (milestone_id=0)
@@ -245,6 +251,7 @@ func TestRepoProjectFilterByMilestone(t *testing.T) {
 		assert.Contains(t, issueIDs, int64(2))
 		assert.Contains(t, issueIDs, int64(3))
 		assert.Contains(t, issueIDs, int64(5))
+		assert.Equal(t, []string{"milestone1", "milestone3"}, getProjectMilestoneNames(htmlDoc))
 	})
 
 	t.Run("FilterByMilestone", func(t *testing.T) {
@@ -300,6 +307,7 @@ func TestOrgProjectFilterByMilestone(t *testing.T) {
 		Name:   "org-test-milestone",
 	}
 	require.NoError(t, issues_model.NewMilestone(t.Context(), milestone))
+	require.NoError(t, issues_model.NewMilestone(t.Context(), &issues_model.Milestone{RepoID: repo.ID, Name: "unlinked-milestone"}))
 
 	issue16.MilestoneID = milestone.ID
 	require.NoError(t, issues_model.UpdateIssueCols(t.Context(), issue16, "milestone_id"))
@@ -327,6 +335,7 @@ func TestOrgProjectFilterByMilestone(t *testing.T) {
 		issueIDs := getProjectIssueIDs(t, htmlDoc)
 		assert.Contains(t, issueIDs, issue16.ID)
 		assert.Contains(t, issueIDs, issue17.ID)
+		assert.Equal(t, []string{milestone.Name}, getProjectMilestoneNames(htmlDoc))
 	})
 
 	t.Run("FilterByMilestone", func(t *testing.T) {