Support using label names when changing issue labels (#30943)

Resolve #30917

Make the APIs for adding labels and replacing labels support both label
IDs and label names so the
[`actions/labeler`](https://github.com/actions/labeler) action can work
in Gitea.

<img width="600px"
src="https://github.com/go-gitea/gitea/assets/15528715/7835c771-f637-4c57-9ce5-e4fbf56fa0d3"
/>

modules/structs/issue_label.go

@@ -47,8 +47,9 @@ type EditLabelOption struct {
 
 // IssueLabelsOption a collection of labels
 type IssueLabelsOption struct {
-	// list of label IDs
-	Labels []int64 `json:"labels"`
+	// Labels can be a list of integers representing label IDs
+	// or a list of strings representing label names
+	Labels []any `json:"labels"`
 }
 
 // LabelTemplate info of a Label template

routers/api/v1/repo/issue_label.go

@@ -5,7 +5,9 @@
 package repo
 
 import (
+	"fmt"
 	"net/http"
+	"reflect"
 
 	issues_model "code.gitea.io/gitea/models/issues"
 	api "code.gitea.io/gitea/modules/structs"
@@ -317,7 +319,32 @@ func prepareForReplaceOrAdd(ctx *context.APIContext, form api.IssueLabelsOption)
 		return nil, nil, err
 	}
 
-	labels, err := issues_model.GetLabelsByIDs(ctx, form.Labels, "id", "repo_id", "org_id", "name", "exclusive")
+	var (
+		labelIDs   []int64
+		labelNames []string
+	)
+	for _, label := range form.Labels {
+		rv := reflect.ValueOf(label)
+		switch rv.Kind() {
+		case reflect.Float64:
+			labelIDs = append(labelIDs, int64(rv.Float()))
+		case reflect.String:
+			labelNames = append(labelNames, rv.String())
+		}
+	}
+	if len(labelIDs) > 0 && len(labelNames) > 0 {
+		ctx.Error(http.StatusBadRequest, "InvalidLabels", "labels should be an array of strings or integers")
+		return nil, nil, fmt.Errorf("invalid labels")
+	}
+	if len(labelNames) > 0 {
+		labelIDs, err = issues_model.GetLabelIDsInRepoByNames(ctx, ctx.Repo.Repository.ID, labelNames)
+		if err != nil {
+			ctx.Error(http.StatusInternalServerError, "GetLabelIDsInRepoByNames", err)
+			return nil, nil, err
+		}
+	}
+
+	labels, err := issues_model.GetLabelsByIDs(ctx, labelIDs, "id", "repo_id", "org_id", "name", "exclusive")
 	if err != nil {
 		ctx.Error(http.StatusInternalServerError, "GetLabelsByIDs", err)
 		return nil, nil, err

templates/swagger/v1_json.tmpl

@@ -21897,12 +21897,9 @@
       "type": "object",
       "properties": {
         "labels": {
-          "description": "list of label IDs",
+          "description": "Labels can be a list of integers representing label IDs\nor a list of strings representing label names",
           "type": "array",
-          "items": {
-            "type": "integer",
-            "format": "int64"
-          },
+          "items": {},
           "x-go-name": "Labels"
         }
       },

tests/integration/api_issue_label_test.go

@@ -104,7 +104,7 @@ func TestAPIAddIssueLabels(t *testing.T) {
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels",
 		repo.OwnerName, repo.Name, issue.Index)
 	req := NewRequestWithJSON(t, "POST", urlStr, &api.IssueLabelsOption{
-		Labels: []int64{1, 2},
+		Labels: []any{1, 2},
 	}).AddTokenAuth(token)
 	resp := MakeRequest(t, req, http.StatusOK)
 	var apiLabels []*api.Label
@@ -114,6 +114,32 @@ func TestAPIAddIssueLabels(t *testing.T) {
 	unittest.AssertExistsAndLoadBean(t, &issues_model.IssueLabel{IssueID: issue.ID, LabelID: 2})
 }
 
+func TestAPIAddIssueLabelsWithLabelNames(t *testing.T) {
+	assert.NoError(t, unittest.LoadFixtures())
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{RepoID: repo.ID})
+	owner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+
+	session := loginUser(t, owner.Name)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue)
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels",
+		repo.OwnerName, repo.Name, issue.Index)
+	req := NewRequestWithJSON(t, "POST", urlStr, &api.IssueLabelsOption{
+		Labels: []any{"label1", "label2"},
+	}).AddTokenAuth(token)
+	resp := MakeRequest(t, req, http.StatusOK)
+	var apiLabels []*api.Label
+	DecodeJSON(t, resp, &apiLabels)
+	assert.Len(t, apiLabels, unittest.GetCount(t, &issues_model.IssueLabel{IssueID: issue.ID}))
+
+	var apiLabelNames []string
+	for _, label := range apiLabels {
+		apiLabelNames = append(apiLabelNames, label.Name)
+	}
+	assert.ElementsMatch(t, apiLabelNames, []string{"label1", "label2"})
+}
+
 func TestAPIReplaceIssueLabels(t *testing.T) {
 	assert.NoError(t, unittest.LoadFixtures())
 
@@ -127,7 +153,7 @@ func TestAPIReplaceIssueLabels(t *testing.T) {
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels",
 		owner.Name, repo.Name, issue.Index)
 	req := NewRequestWithJSON(t, "PUT", urlStr, &api.IssueLabelsOption{
-		Labels: []int64{label.ID},
+		Labels: []any{label.ID},
 	}).AddTokenAuth(token)
 	resp := MakeRequest(t, req, http.StatusOK)
 	var apiLabels []*api.Label
@@ -140,6 +166,29 @@ func TestAPIReplaceIssueLabels(t *testing.T) {
 	unittest.AssertExistsAndLoadBean(t, &issues_model.IssueLabel{IssueID: issue.ID, LabelID: label.ID})
 }
 
+func TestAPIReplaceIssueLabelsWithLabelNames(t *testing.T) {
+	assert.NoError(t, unittest.LoadFixtures())
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{RepoID: repo.ID})
+	label := unittest.AssertExistsAndLoadBean(t, &issues_model.Label{RepoID: repo.ID})
+	owner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+
+	session := loginUser(t, owner.Name)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue)
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/labels",
+		owner.Name, repo.Name, issue.Index)
+	req := NewRequestWithJSON(t, "PUT", urlStr, &api.IssueLabelsOption{
+		Labels: []any{label.Name},
+	}).AddTokenAuth(token)
+	resp := MakeRequest(t, req, http.StatusOK)
+	var apiLabels []*api.Label
+	DecodeJSON(t, resp, &apiLabels)
+	if assert.Len(t, apiLabels, 1) {
+		assert.EqualValues(t, label.Name, apiLabels[0].Name)
+	}
+}
+
 func TestAPIModifyOrgLabels(t *testing.T) {
 	assert.NoError(t, unittest.LoadFixtures())