add Upload URL to release API (#26663)

- Resolves https://codeberg.org/forgejo/forgejo/issues/580
- Return a `upload_field` to any release API response, which points to
the API URL for uploading new assets.
- Adds unit test.
- Adds integration testing to verify URL is returned correctly and that
upload endpoint actually works

---------

Co-authored-by: Gusted <postmaster@gusted.xyz>

6 files changed, 79 insertions, 0 deletions

diff --git a/models/repo/release.go b/models/repo/release.go
index a00585111e..191475d541 100644
--- a/models/repo/release.go
+++ b/models/repo/release.go
@@ -133,6 +133,11 @@ func (r *Release) HTMLURL() string {
 	return r.Repo.HTMLURL() + "/releases/tag/" + util.PathEscapeSegments(r.TagName)
 }
 
+// APIUploadURL the api url to upload assets to a release. release must have attributes loaded
+func (r *Release) APIUploadURL() string {
+	return r.APIURL() + "/assets"
+}
+
 // Link the relative url for a release on the web UI. release must have attributes loaded
 func (r *Release) Link() string {
 	return r.Repo.Link() + "/releases/tag/" + util.PathEscapeSegments(r.TagName)
diff --git a/modules/structs/release.go b/modules/structs/release.go
index 3fe40389b1..c7378645c2 100644
--- a/modules/structs/release.go
+++ b/modules/structs/release.go
@@ -18,6 +18,7 @@ type Release struct {
 	HTMLURL      string `json:"html_url"`
 	TarURL       string `json:"tarball_url"`
 	ZipURL       string `json:"zipball_url"`
+	UploadURL    string `json:"upload_url"`
 	IsDraft      bool   `json:"draft"`
 	IsPrerelease bool   `json:"prerelease"`
 	// swagger:strfmt date-time
diff --git a/services/convert/release.go b/services/convert/release.go
index d8aa46d432..bfff53e62f 100644
--- a/services/convert/release.go
+++ b/services/convert/release.go
@@ -22,6 +22,7 @@ func ToAPIRelease(ctx context.Context, repo *repo_model.Repository, r *repo_mode
 		HTMLURL:      r.HTMLURL(),
 		TarURL:       r.TarURL(),
 		ZipURL:       r.ZipURL(),
+		UploadURL:    r.APIUploadURL(),
 		IsDraft:      r.IsDraft,
 		IsPrerelease: r.IsPrerelease,
 		CreatedAt:    r.CreatedUnix.AsTime(),
diff --git a/services/convert/release_test.go b/services/convert/release_test.go
new file mode 100644
index 0000000000..201b27e16d
--- /dev/null
+++ b/services/convert/release_test.go
@@ -0,0 +1,28 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package convert
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRelease_ToRelease(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	repo1 := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	release1 := unittest.AssertExistsAndLoadBean(t, &repo_model.Release{ID: 1})
+	release1.LoadAttributes(db.DefaultContext)
+
+	apiRelease := ToAPIRelease(db.DefaultContext, repo1, release1)
+	assert.NotNil(t, apiRelease)
+	assert.EqualValues(t, 1, apiRelease.ID)
+	assert.EqualValues(t, "https://try.gitea.io/api/v1/repos/user2/repo1/releases/1", apiRelease.URL)
+	assert.EqualValues(t, "https://try.gitea.io/api/v1/repos/user2/repo1/releases/1/assets", apiRelease.UploadURL)
+}
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index aff4490899..ca4e1c4606 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -21090,6 +21090,10 @@
           "type": "string",
           "x-go-name": "Target"
         },
+        "upload_url": {
+          "type": "string",
+          "x-go-name": "UploadURL"
+        },
         "url": {
           "type": "string",
           "x-go-name": "URL"
diff --git a/tests/integration/api_releases_test.go b/tests/integration/api_releases_test.go
index 7f43939083..526842d5ac 100644
--- a/tests/integration/api_releases_test.go
+++ b/tests/integration/api_releases_test.go
@@ -4,9 +4,13 @@
 package integration
 
 import (
+	"bytes"
 	"fmt"
+	"io"
+	"mime/multipart"
 	"net/http"
 	"net/url"
+	"strings"
 	"testing"
 
 	auth_model "code.gitea.io/gitea/models/auth"
@@ -38,12 +42,15 @@ func TestAPIListReleases(t *testing.T) {
 			case 1:
 				assert.False(t, release.IsDraft)
 				assert.False(t, release.IsPrerelease)
+				assert.True(t, strings.HasSuffix(release.UploadURL, "/api/v1/repos/user2/repo1/releases/1/assets"), release.UploadURL)
 			case 4:
 				assert.True(t, release.IsDraft)
 				assert.False(t, release.IsPrerelease)
+				assert.True(t, strings.HasSuffix(release.UploadURL, "/api/v1/repos/user2/repo1/releases/4/assets"), release.UploadURL)
 			case 5:
 				assert.False(t, release.IsDraft)
 				assert.True(t, release.IsPrerelease)
+				assert.True(t, strings.HasSuffix(release.UploadURL, "/api/v1/repos/user2/repo1/releases/5/assets"), release.UploadURL)
 			default:
 				assert.NoError(t, fmt.Errorf("unexpected release: %v", release))
 			}
@@ -248,3 +255,36 @@ func TestAPIDeleteReleaseByTagName(t *testing.T) {
 	req = NewRequestf(t, http.MethodDelete, fmt.Sprintf("/api/v1/repos/%s/%s/tags/release-tag?token=%s", owner.Name, repo.Name, token))
 	_ = MakeRequest(t, req, http.StatusNoContent)
 }
+
+func TestAPIUploadAssetRelease(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+	owner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+	session := loginUser(t, owner.LowerName)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteRepository)
+
+	r := createNewReleaseUsingAPI(t, session, token, owner, repo, "release-tag", "", "Release Tag", "test")
+
+	filename := "image.png"
+	buff := generateImg()
+	body := &bytes.Buffer{}
+
+	writer := multipart.NewWriter(body)
+	part, err := writer.CreateFormFile("attachment", filename)
+	assert.NoError(t, err)
+	_, err = io.Copy(part, &buff)
+	assert.NoError(t, err)
+	err = writer.Close()
+	assert.NoError(t, err)
+
+	req := NewRequestWithBody(t, http.MethodPost, fmt.Sprintf("/api/v1/repos/%s/%s/releases/%d/assets?name=test-asset&token=%s", owner.Name, repo.Name, r.ID, token), body)
+	req.Header.Add("Content-Type", writer.FormDataContentType())
+	resp := MakeRequest(t, req, http.StatusCreated)
+
+	var attachment *api.Attachment
+	DecodeJSON(t, resp, &attachment)
+
+	assert.EqualValues(t, "test-asset", attachment.Name)
+	assert.EqualValues(t, 104, attachment.Size)
+}