[feature] Allow newly uploaded emojis to be placed in categories (#939)

* [feature] Add emoji categories GET
Serialize emojis in appropriate categories; make it possible to get categories via the admin API

* [feature] Create (or use existing) category for new emoji uploads

* fix lint issue

* update misleading line in swagger docs

docs/api/swagger.yaml

@@ -859,8 +859,27 @@ definitions:
         type: object
         x-go-name: Emoji
         x-go-package: github.com/superseriousbusiness/gotosocial/internal/api/model
+    emojiCategory:
+        properties:
+            id:
+                description: The ID of the custom emoji category.
+                type: string
+                x-go-name: ID
+            name:
+                description: The name of the custom emoji category.
+                type: string
+                x-go-name: Name
+        title: EmojiCategory represents a custom emoji category.
+        type: object
+        x-go-name: EmojiCategory
+        x-go-package: github.com/superseriousbusiness/gotosocial/internal/api/model
     emojiCreateRequest:
         properties:
+            CategoryName:
+                description: |-
+                    Category in which to place the new emoji. Will be uncategorized by default.
+                    CategoryName length should not exceed 64 characters.
+                type: string
             Image:
                 description: Image file to use for the emoji. Must be png or gif and no larger than 50kb.
             Shortcode:
@@ -2755,6 +2774,10 @@ paths:
                   name: image
                   required: true
                   type: file
+                - description: Category in which to place the new emoji. 64 characters or less. If left blank, emoji will be uncategorized. If a category with the given name doesn't exist yet, it will be created.
+                  in: formData
+                  name: category
+                  type: string
             produces:
                 - application/json
             responses:
@@ -2852,6 +2875,39 @@ paths:
             summary: Get the admin view of a single emoji.
             tags:
                 - admin
+    /api/v1/admin/custom_emojis/categories:
+        get:
+            operationId: emojiCategoriesGet
+            parameters:
+                - description: The id of the emoji.
+                  in: path
+                  name: id
+                  required: true
+                  type: string
+            produces:
+                - application/json
+            responses:
+                "200":
+                    description: Array of existing emoji categories.
+                    schema:
+                        items:
+                            $ref: '#/definitions/adminEmojiCategory'
+                        type: array
+                "400":
+                    description: bad request
+                "401":
+                    description: unauthorized
+                "403":
+                    description: forbidden
+                "404":
+                    description: not found
+                "406":
+                    description: not acceptable
+                "500":
+                    description: internal server error
+            summary: Get a list of existing emoji categories.
+            tags:
+                - admin
     /api/v1/admin/domain_blocks:
         get:
             operationId: domainBlocksGet

internal/api/client/admin/admin.go

@@ -33,6 +33,8 @@ const (
 	EmojiPath = BasePath + "/custom_emojis"
 	// EmojiPathWithID is used for interacting with a single emoji.
 	EmojiPathWithID = EmojiPath + "/:" + IDKey
+	// EmojiCategoriesPath is used for interacting with emoji categories.
+	EmojiCategoriesPath = EmojiPath + "/categories"
 	// DomainBlocksPath is used for posting domain blocks.
 	DomainBlocksPath = BasePath + "/domain_blocks"
 	// DomainBlocksPathWithID is used for interacting with a single domain block.
@@ -87,5 +89,6 @@ func (m *Module) Route(r router.Router) error {
 	r.AttachHandler(http.MethodDelete, DomainBlocksPathWithID, m.DomainBlockDELETEHandler)
 	r.AttachHandler(http.MethodPost, AccountsActionPath, m.AccountActionPOSTHandler)
 	r.AttachHandler(http.MethodPost, MediaCleanupPath, m.MediaCleanupPOSTHandler)
+	r.AttachHandler(http.MethodGet, EmojiCategoriesPath, m.EmojiCategoriesGETHandler)
 	return nil
 }

internal/api/client/admin/admin_test.go

@@ -53,14 +53,15 @@ type AdminStandardTestSuite struct {
 	sentEmails   map[string]string
 
 	// standard suite models
-	testTokens       map[string]*gtsmodel.Token
+	testTokens          map[string]*gtsmodel.Token
-	testClients      map[string]*gtsmodel.Client
+	testClients         map[string]*gtsmodel.Client
-	testApplications map[string]*gtsmodel.Application
+	testApplications    map[string]*gtsmodel.Application
-	testUsers        map[string]*gtsmodel.User
+	testUsers           map[string]*gtsmodel.User
-	testAccounts     map[string]*gtsmodel.Account
+	testAccounts        map[string]*gtsmodel.Account
-	testAttachments  map[string]*gtsmodel.MediaAttachment
+	testAttachments     map[string]*gtsmodel.MediaAttachment
-	testStatuses     map[string]*gtsmodel.Status
+	testStatuses        map[string]*gtsmodel.Status
-	testEmojis       map[string]*gtsmodel.Emoji
+	testEmojis          map[string]*gtsmodel.Emoji
+	testEmojiCategories map[string]*gtsmodel.EmojiCategory
 
 	// module being tested
 	adminModule *admin.Module
@@ -75,6 +76,7 @@ func (suite *AdminStandardTestSuite) SetupSuite() {
 	suite.testAttachments = testrig.NewTestAttachments()
 	suite.testStatuses = testrig.NewTestStatuses()
 	suite.testEmojis = testrig.NewTestEmojis()
+	suite.testEmojiCategories = testrig.NewTestEmojiCategories()
 }
 
 func (suite *AdminStandardTestSuite) SetupTest() {

internal/api/client/admin/emojicategoriesget.go

@@ -0,0 +1,94 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package admin
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/superseriousbusiness/gotosocial/internal/api"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/oauth"
+)
+
+// EmojiCategoriesGETHandler swagger:operation GET /api/v1/admin/custom_emojis/categories emojiCategoriesGet
+//
+// Get a list of existing emoji categories.
+//
+//	---
+//	tags:
+//	- admin
+//
+//	produces:
+//	- application/json
+//
+//	parameters:
+//	-
+//		name: id
+//		type: string
+//		description: The id of the emoji.
+//		in: path
+//		required: true
+//
+//	responses:
+//		'200':
+//			description: Array of existing emoji categories.
+//			schema:
+//				type: array
+//				items:
+//					"$ref": "#/definitions/adminEmojiCategory"
+//		'400':
+//			description: bad request
+//		'401':
+//			description: unauthorized
+//		'403':
+//			description: forbidden
+//		'404':
+//			description: not found
+//		'406':
+//			description: not acceptable
+//		'500':
+//			description: internal server error
+func (m *Module) EmojiCategoriesGETHandler(c *gin.Context) {
+	authed, err := oauth.Authed(c, true, true, true, true)
+	if err != nil {
+		api.ErrorHandler(c, gtserror.NewErrorUnauthorized(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if !*authed.User.Admin {
+		err := fmt.Errorf("user %s not an admin", authed.User.ID)
+		api.ErrorHandler(c, gtserror.NewErrorForbidden(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	if _, err := api.NegotiateAccept(c, api.JSONAcceptHeaders...); err != nil {
+		api.ErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), m.processor.InstanceGet)
+		return
+	}
+
+	categories, errWithCode := m.processor.AdminEmojiCategoriesGet(c.Request.Context())
+	if errWithCode != nil {
+		api.ErrorHandler(c, errWithCode, m.processor.InstanceGet)
+		return
+	}
+
+	c.JSON(http.StatusOK, categories)
+}

internal/api/client/admin/emojicategoriesget_test.go

@@ -0,0 +1,53 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package admin_test
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/api/client/admin"
+)
+
+type EmojiCategoriesGetTestSuite struct {
+	AdminStandardTestSuite
+}
+
+func (suite *EmojiCategoriesGetTestSuite) TestEmojiCategoriesGet() {
+	recorder := httptest.NewRecorder()
+
+	path := admin.EmojiCategoriesPath
+	ctx := suite.newContext(recorder, http.MethodGet, nil, path, "application/json")
+
+	suite.adminModule.EmojiCategoriesGETHandler(ctx)
+	suite.Equal(http.StatusOK, recorder.Code)
+
+	b, err := io.ReadAll(recorder.Body)
+	suite.NoError(err)
+	suite.NotNil(b)
+
+	suite.Equal(`[{"id":"01GGQ989PTT9PMRN4FZ1WWK2B9","name":"cute stuff"},{"id":"01GGQ8V4993XK67B2JB396YFB7","name":"reactions"}]`, string(b))
+}
+
+func TestEmojiCategoriesGetTestSuite(t *testing.T) {
+	suite.Run(t, &EmojiCategoriesGetTestSuite{})
+}

internal/api/client/admin/emojicreate.go

@@ -64,6 +64,15 @@ import (
 //			To ensure compatibility with other fedi implementations, emoji size limit is 50kb by default.
 //		type: file
 //		required: true
+//	-
+//		name: category
+//		in: formData
+//		description: >-
+//			Category in which to place the new emoji. 64 characters or less.
+//			If left blank, emoji will be uncategorized. If a category with the
+//			given name doesn't exist yet, it will be created.
+//		type: string
+//		required: false
 //
 //	security:
 //	- OAuth2 Bearer:
@@ -136,5 +145,9 @@ func validateCreateEmoji(form *model.EmojiCreateRequest) error {
 		return fmt.Errorf("emoji image too large: image is %dKB but size limit for custom emojis is %dKB", form.Image.Size/1024, maxSize/1024)
 	}
 
-	return validate.EmojiShortcode(form.Shortcode)
+	if err := validate.EmojiShortcode(form.Shortcode); err != nil {
+		return err
+	}
+
+	return validate.EmojiCategory(form.CategoryName)
 }

internal/api/client/admin/emojicreate_test.go

@@ -36,12 +36,159 @@ type EmojiCreateTestSuite struct {
 	AdminStandardTestSuite
 }
 
-func (suite *EmojiCreateTestSuite) TestEmojiCreate() {
+func (suite *EmojiCreateTestSuite) TestEmojiCreateNewCategory() {
 	// set up the request
 	requestBody, w, err := testrig.CreateMultipartFormData(
 		"image", "../../../../testrig/media/rainbow-original.png",
 		map[string]string{
 			"shortcode": "new_emoji",
+			"category":  "Test Emojis", // this category doesn't exist yet
+		})
+	if err != nil {
+		panic(err)
+	}
+	bodyBytes := requestBody.Bytes()
+	recorder := httptest.NewRecorder()
+	ctx := suite.newContext(recorder, http.MethodPost, bodyBytes, admin.EmojiPath, w.FormDataContentType())
+
+	// call the handler
+	suite.adminModule.EmojiCreatePOSTHandler(ctx)
+
+	// 1. we should have OK because our request was valid
+	suite.Equal(http.StatusOK, recorder.Code)
+
+	// 2. we should have no error message in the result body
+	result := recorder.Result()
+	defer result.Body.Close()
+
+	// check the response
+	b, err := ioutil.ReadAll(result.Body)
+	suite.NoError(err)
+	suite.NotEmpty(b)
+
+	// response should be an api model emoji
+	apiEmoji := &apimodel.Emoji{}
+	err = json.Unmarshal(b, apiEmoji)
+	suite.NoError(err)
+
+	// appropriate fields should be set
+	suite.Equal("new_emoji", apiEmoji.Shortcode)
+	suite.NotEmpty(apiEmoji.URL)
+	suite.NotEmpty(apiEmoji.StaticURL)
+	suite.True(apiEmoji.VisibleInPicker)
+
+	// emoji should be in the db
+	dbEmoji, err := suite.db.GetEmojiByShortcodeDomain(context.Background(), apiEmoji.Shortcode, "")
+	suite.NoError(err)
+
+	// check fields on the emoji
+	suite.NotEmpty(dbEmoji.ID)
+	suite.Equal("new_emoji", dbEmoji.Shortcode)
+	suite.Empty(dbEmoji.Domain)
+	suite.Empty(dbEmoji.ImageRemoteURL)
+	suite.Empty(dbEmoji.ImageStaticRemoteURL)
+	suite.Equal(apiEmoji.URL, dbEmoji.ImageURL)
+	suite.Equal(apiEmoji.StaticURL, dbEmoji.ImageStaticURL)
+	suite.NotEmpty(dbEmoji.ImagePath)
+	suite.NotEmpty(dbEmoji.ImageStaticPath)
+	suite.Equal("image/png", dbEmoji.ImageContentType)
+	suite.Equal("image/png", dbEmoji.ImageStaticContentType)
+	suite.Equal(36702, dbEmoji.ImageFileSize)
+	suite.Equal(10413, dbEmoji.ImageStaticFileSize)
+	suite.False(*dbEmoji.Disabled)
+	suite.NotEmpty(dbEmoji.URI)
+	suite.True(*dbEmoji.VisibleInPicker)
+	suite.NotEmpty(dbEmoji.CategoryID)
+
+	// emoji should be in storage
+	emojiBytes, err := suite.storage.Get(ctx, dbEmoji.ImagePath)
+	suite.NoError(err)
+	suite.Len(emojiBytes, dbEmoji.ImageFileSize)
+	emojiStaticBytes, err := suite.storage.Get(ctx, dbEmoji.ImageStaticPath)
+	suite.NoError(err)
+	suite.Len(emojiStaticBytes, dbEmoji.ImageStaticFileSize)
+}
+
+func (suite *EmojiCreateTestSuite) TestEmojiCreateExistingCategory() {
+	// set up the request
+	requestBody, w, err := testrig.CreateMultipartFormData(
+		"image", "../../../../testrig/media/rainbow-original.png",
+		map[string]string{
+			"shortcode": "new_emoji",
+			"category":  "cute stuff", // this category already exists
+		})
+	if err != nil {
+		panic(err)
+	}
+	bodyBytes := requestBody.Bytes()
+	recorder := httptest.NewRecorder()
+	ctx := suite.newContext(recorder, http.MethodPost, bodyBytes, admin.EmojiPath, w.FormDataContentType())
+
+	// call the handler
+	suite.adminModule.EmojiCreatePOSTHandler(ctx)
+
+	// 1. we should have OK because our request was valid
+	suite.Equal(http.StatusOK, recorder.Code)
+
+	// 2. we should have no error message in the result body
+	result := recorder.Result()
+	defer result.Body.Close()
+
+	// check the response
+	b, err := ioutil.ReadAll(result.Body)
+	suite.NoError(err)
+	suite.NotEmpty(b)
+
+	// response should be an api model emoji
+	apiEmoji := &apimodel.Emoji{}
+	err = json.Unmarshal(b, apiEmoji)
+	suite.NoError(err)
+
+	// appropriate fields should be set
+	suite.Equal("new_emoji", apiEmoji.Shortcode)
+	suite.NotEmpty(apiEmoji.URL)
+	suite.NotEmpty(apiEmoji.StaticURL)
+	suite.True(apiEmoji.VisibleInPicker)
+
+	// emoji should be in the db
+	dbEmoji, err := suite.db.GetEmojiByShortcodeDomain(context.Background(), apiEmoji.Shortcode, "")
+	suite.NoError(err)
+
+	// check fields on the emoji
+	suite.NotEmpty(dbEmoji.ID)
+	suite.Equal("new_emoji", dbEmoji.Shortcode)
+	suite.Empty(dbEmoji.Domain)
+	suite.Empty(dbEmoji.ImageRemoteURL)
+	suite.Empty(dbEmoji.ImageStaticRemoteURL)
+	suite.Equal(apiEmoji.URL, dbEmoji.ImageURL)
+	suite.Equal(apiEmoji.StaticURL, dbEmoji.ImageStaticURL)
+	suite.NotEmpty(dbEmoji.ImagePath)
+	suite.NotEmpty(dbEmoji.ImageStaticPath)
+	suite.Equal("image/png", dbEmoji.ImageContentType)
+	suite.Equal("image/png", dbEmoji.ImageStaticContentType)
+	suite.Equal(36702, dbEmoji.ImageFileSize)
+	suite.Equal(10413, dbEmoji.ImageStaticFileSize)
+	suite.False(*dbEmoji.Disabled)
+	suite.NotEmpty(dbEmoji.URI)
+	suite.True(*dbEmoji.VisibleInPicker)
+	suite.Equal(suite.testEmojiCategories["cute stuff"].ID, dbEmoji.CategoryID)
+
+	// emoji should be in storage
+	emojiBytes, err := suite.storage.Get(ctx, dbEmoji.ImagePath)
+	suite.NoError(err)
+	suite.Len(emojiBytes, dbEmoji.ImageFileSize)
+	emojiStaticBytes, err := suite.storage.Get(ctx, dbEmoji.ImageStaticPath)
+	suite.NoError(err)
+	suite.Len(emojiStaticBytes, dbEmoji.ImageStaticFileSize)
+}
+
+func (suite *EmojiCreateTestSuite) TestEmojiCreateNoCategory() {
+	// set up the request
+	requestBody, w, err := testrig.CreateMultipartFormData(
+		"image", "../../../../testrig/media/rainbow-original.png",
+		map[string]string{
+			"shortcode": "new_emoji",
+			"category":  "",
 		})
 	if err != nil {
 		panic(err)

internal/api/client/admin/emojidelete_test.go

@@ -49,7 +49,7 @@ func (suite *EmojiDeleteTestSuite) TestEmojiDelete1() {
 	suite.NoError(err)
 	suite.NotNil(b)
 
-	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
+	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions","id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
 
 	// emoji should no longer be in the db
 	dbEmoji, err := suite.db.GetEmojiByID(context.Background(), testEmoji.ID)

internal/api/client/admin/emojiget_test.go

@@ -47,7 +47,7 @@ func (suite *EmojiGetTestSuite) TestEmojiGet1() {
 	suite.NoError(err)
 	suite.NotNil(b)
 
-	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
+	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions","id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
 }
 
 func (suite *EmojiGetTestSuite) TestEmojiGet2() {

internal/api/model/emoji.go

@@ -50,4 +50,7 @@ type EmojiCreateRequest struct {
 	Shortcode string `form:"shortcode" validation:"required"`
 	// Image file to use for the emoji. Must be png or gif and no larger than 50kb.
 	Image *multipart.FileHeader `form:"image" validation:"required"`
+	// Category in which to place the new emoji. Will be uncategorized by default.
+	// CategoryName length should not exceed 64 characters.
+	CategoryName string `form:"category"`
 }

internal/api/model/emojicategory.go

@@ -0,0 +1,29 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package model
+
+// EmojiCategory represents a custom emoji category.
+//
+// swagger:model emojiCategory
+type EmojiCategory struct {
+	// The ID of the custom emoji category.
+	ID string `json:"id"`
+	// The name of the custom emoji category.
+	Name string `json:"name"`
+}

internal/cache/emojicategory.go

@@ -0,0 +1,84 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package cache
+
+import (
+	"strings"
+	"time"
+
+	"codeberg.org/gruf/go-cache/v2"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// EmojiCategoryCache is a cache wrapper to provide ID lookups for gtsmodel.EmojiCategory
+type EmojiCategoryCache struct {
+	cache cache.LookupCache[string, string, *gtsmodel.EmojiCategory]
+}
+
+// NewEmojiCategoryCache returns a new instantiated EmojiCategoryCache object
+func NewEmojiCategoryCache() *EmojiCategoryCache {
+	c := &EmojiCategoryCache{}
+	c.cache = cache.NewLookup(cache.LookupCfg[string, string, *gtsmodel.EmojiCategory]{
+		RegisterLookups: func(lm *cache.LookupMap[string, string]) {
+			lm.RegisterLookup("name")
+		},
+
+		AddLookups: func(lm *cache.LookupMap[string, string], emojiCategory *gtsmodel.EmojiCategory) {
+			lm.Set(("name"), strings.ToLower(emojiCategory.Name), emojiCategory.ID)
+		},
+
+		DeleteLookups: func(lm *cache.LookupMap[string, string], emojiCategory *gtsmodel.EmojiCategory) {
+			lm.Delete("name", strings.ToLower(emojiCategory.Name))
+		},
+	})
+	c.cache.SetTTL(time.Minute*5, false)
+	c.cache.Start(time.Second * 10)
+	return c
+}
+
+// GetByID attempts to fetch an emojiCategory from the cache by its ID, you will receive a copy for thread-safety
+func (c *EmojiCategoryCache) GetByID(id string) (*gtsmodel.EmojiCategory, bool) {
+	return c.cache.Get(id)
+}
+
+// GetByName attempts to fetch an emojiCategory from the cache by its name, you will receive a copy for thread-safety
+func (c *EmojiCategoryCache) GetByName(name string) (*gtsmodel.EmojiCategory, bool) {
+	return c.cache.GetBy("name", strings.ToLower(name))
+}
+
+// Put places an emojiCategory in the cache, ensuring that the object place is a copy for thread-safety
+func (c *EmojiCategoryCache) Put(emoji *gtsmodel.EmojiCategory) {
+	if emoji == nil || emoji.ID == "" {
+		panic("invalid emoji")
+	}
+	c.cache.Set(emoji.ID, copyEmojiCategory(emoji))
+}
+
+func (c *EmojiCategoryCache) Invalidate(emojiID string) {
+	c.cache.Invalidate(emojiID)
+}
+
+func copyEmojiCategory(emojiCategory *gtsmodel.EmojiCategory) *gtsmodel.EmojiCategory {
+	return &gtsmodel.EmojiCategory{
+		ID:        emojiCategory.ID,
+		CreatedAt: emojiCategory.CreatedAt,
+		UpdatedAt: emojiCategory.UpdatedAt,
+		Name:      emojiCategory.Name,
+	}
+}

internal/db/bundb/bundb.go

@@ -180,7 +180,7 @@ func NewBunDBService(ctx context.Context) (db.DB, error) {
 	// Create DB structs that require ptrs to each other
 	accounts := &accountDB{conn: conn, cache: accountCache}
 	status := &statusDB{conn: conn, cache: cache.NewStatusCache()}
-	emoji := &emojiDB{conn: conn, cache: cache.NewEmojiCache()}
+	emoji := &emojiDB{conn: conn, emojiCache: cache.NewEmojiCache(), categoryCache: cache.NewEmojiCategoryCache()}
 	timeline := &timelineDB{conn: conn}
 	tombstone := &tombstoneDB{conn: conn}
 

internal/db/bundb/emoji.go

@@ -32,14 +32,22 @@ import (
 )
 
 type emojiDB struct {
-	conn  *DBConn
+	conn          *DBConn
-	cache *cache.EmojiCache
+	emojiCache    *cache.EmojiCache
+	categoryCache *cache.EmojiCategoryCache
 }
 
 func (e *emojiDB) newEmojiQ(emoji *gtsmodel.Emoji) *bun.SelectQuery {
 	return e.conn.
 		NewSelect().
-		Model(emoji)
+		Model(emoji).
+		Relation("Category")
+}
+
+func (e *emojiDB) newEmojiCategoryQ(emojiCategory *gtsmodel.EmojiCategory) *bun.SelectQuery {
+	return e.conn.
+		NewSelect().
+		Model(emojiCategory)
 }
 
 func (e *emojiDB) PutEmoji(ctx context.Context, emoji *gtsmodel.Emoji) db.Error {
@@ -47,7 +55,7 @@ func (e *emojiDB) PutEmoji(ctx context.Context, emoji *gtsmodel.Emoji) db.Error
 		return e.conn.ProcessError(err)
 	}
 
-	e.cache.Put(emoji)
+	e.emojiCache.Put(emoji)
 	return nil
 }
 
@@ -64,7 +72,7 @@ func (e *emojiDB) UpdateEmoji(ctx context.Context, emoji *gtsmodel.Emoji, column
 		return nil, e.conn.ProcessError(err)
 	}
 
-	e.cache.Invalidate(emoji.ID)
+	e.emojiCache.Invalidate(emoji.ID)
 	return emoji, nil
 }
 
@@ -101,7 +109,7 @@ func (e *emojiDB) DeleteEmojiByID(ctx context.Context, id string) db.Error {
 		return err
 	}
 
-	e.cache.Invalidate(id)
+	e.emojiCache.Invalidate(id)
 	return nil
 }
 
@@ -245,7 +253,7 @@ func (e *emojiDB) GetEmojiByID(ctx context.Context, id string) (*gtsmodel.Emoji,
 	return e.getEmoji(
 		ctx,
 		func() (*gtsmodel.Emoji, bool) {
-			return e.cache.GetByID(id)
+			return e.emojiCache.GetByID(id)
 		},
 		func(emoji *gtsmodel.Emoji) error {
 			return e.newEmojiQ(emoji).Where("? = ?", bun.Ident("emoji.id"), id).Scan(ctx)
@@ -257,7 +265,7 @@ func (e *emojiDB) GetEmojiByURI(ctx context.Context, uri string) (*gtsmodel.Emoj
 	return e.getEmoji(
 		ctx,
 		func() (*gtsmodel.Emoji, bool) {
-			return e.cache.GetByURI(uri)
+			return e.emojiCache.GetByURI(uri)
 		},
 		func(emoji *gtsmodel.Emoji) error {
 			return e.newEmojiQ(emoji).Where("? = ?", bun.Ident("emoji.uri"), uri).Scan(ctx)
@@ -269,7 +277,7 @@ func (e *emojiDB) GetEmojiByShortcodeDomain(ctx context.Context, shortcode strin
 	return e.getEmoji(
 		ctx,
 		func() (*gtsmodel.Emoji, bool) {
-			return e.cache.GetByShortcodeDomain(shortcode, domain)
+			return e.emojiCache.GetByShortcodeDomain(shortcode, domain)
 		},
 		func(emoji *gtsmodel.Emoji) error {
 			q := e.newEmojiQ(emoji)
@@ -291,7 +299,7 @@ func (e *emojiDB) GetEmojiByStaticURL(ctx context.Context, imageStaticURL string
 	return e.getEmoji(
 		ctx,
 		func() (*gtsmodel.Emoji, bool) {
-			return e.cache.GetByImageStaticURL(imageStaticURL)
+			return e.emojiCache.GetByImageStaticURL(imageStaticURL)
 		},
 		func(emoji *gtsmodel.Emoji) error {
 			return e.
@@ -302,6 +310,55 @@ func (e *emojiDB) GetEmojiByStaticURL(ctx context.Context, imageStaticURL string
 	)
 }
 
+func (e *emojiDB) PutEmojiCategory(ctx context.Context, emojiCategory *gtsmodel.EmojiCategory) db.Error {
+	if _, err := e.conn.NewInsert().Model(emojiCategory).Exec(ctx); err != nil {
+		return e.conn.ProcessError(err)
+	}
+
+	e.categoryCache.Put(emojiCategory)
+	return nil
+}
+
+func (e *emojiDB) GetEmojiCategories(ctx context.Context) ([]*gtsmodel.EmojiCategory, db.Error) {
+	emojiCategoryIDs := []string{}
+
+	q := e.conn.
+		NewSelect().
+		TableExpr("? AS ?", bun.Ident("emoji_categories"), bun.Ident("emoji_category")).
+		Column("emoji_category.id").
+		Order("emoji_category.name ASC")
+
+	if err := q.Scan(ctx, &emojiCategoryIDs); err != nil {
+		return nil, e.conn.ProcessError(err)
+	}
+
+	return e.emojiCategoriesFromIDs(ctx, emojiCategoryIDs)
+}
+
+func (e *emojiDB) GetEmojiCategory(ctx context.Context, id string) (*gtsmodel.EmojiCategory, db.Error) {
+	return e.getEmojiCategory(
+		ctx,
+		func() (*gtsmodel.EmojiCategory, bool) {
+			return e.categoryCache.GetByID(id)
+		},
+		func(emojiCategory *gtsmodel.EmojiCategory) error {
+			return e.newEmojiCategoryQ(emojiCategory).Where("? = ?", bun.Ident("emoji_category.id"), id).Scan(ctx)
+		},
+	)
+}
+
+func (e *emojiDB) GetEmojiCategoryByName(ctx context.Context, name string) (*gtsmodel.EmojiCategory, db.Error) {
+	return e.getEmojiCategory(
+		ctx,
+		func() (*gtsmodel.EmojiCategory, bool) {
+			return e.categoryCache.GetByName(name)
+		},
+		func(emojiCategory *gtsmodel.EmojiCategory) error {
+			return e.newEmojiCategoryQ(emojiCategory).Where("LOWER(?) = ?", bun.Ident("emoji_category.name"), strings.ToLower(name)).Scan(ctx)
+		},
+	)
+}
+
 func (e *emojiDB) getEmoji(ctx context.Context, cacheGet func() (*gtsmodel.Emoji, bool), dbQuery func(*gtsmodel.Emoji) error) (*gtsmodel.Emoji, db.Error) {
 	// Attempt to fetch cached emoji
 	emoji, cached := cacheGet()
@@ -316,7 +373,7 @@ func (e *emojiDB) getEmoji(ctx context.Context, cacheGet func() (*gtsmodel.Emoji
 		}
 
 		// Place in the cache
-		e.cache.Put(emoji)
+		e.emojiCache.Put(emoji)
 	}
 
 	return emoji, nil
@@ -341,3 +398,43 @@ func (e *emojiDB) emojisFromIDs(ctx context.Context, emojiIDs []string) ([]*gtsm
 
 	return emojis, nil
 }
+
+func (e *emojiDB) getEmojiCategory(ctx context.Context, cacheGet func() (*gtsmodel.EmojiCategory, bool), dbQuery func(*gtsmodel.EmojiCategory) error) (*gtsmodel.EmojiCategory, db.Error) {
+	// Attempt to fetch cached emoji categories
+	emojiCategory, cached := cacheGet()
+
+	if !cached {
+		emojiCategory = &gtsmodel.EmojiCategory{}
+
+		// Not cached! Perform database query
+		err := dbQuery(emojiCategory)
+		if err != nil {
+			return nil, e.conn.ProcessError(err)
+		}
+
+		// Place in the cache
+		e.categoryCache.Put(emojiCategory)
+	}
+
+	return emojiCategory, nil
+}
+
+func (e *emojiDB) emojiCategoriesFromIDs(ctx context.Context, emojiCategoryIDs []string) ([]*gtsmodel.EmojiCategory, db.Error) {
+	// Catch case of no emoji categories early
+	if len(emojiCategoryIDs) == 0 {
+		return nil, db.ErrNoEntries
+	}
+
+	emojiCategories := make([]*gtsmodel.EmojiCategory, 0, len(emojiCategoryIDs))
+
+	for _, id := range emojiCategoryIDs {
+		emojiCategory, err := e.GetEmojiCategory(ctx, id)
+		if err != nil {
+			log.Errorf("emojiCategoriesFromIDs: error getting emoji category %q: %v", id, err)
+		}
+
+		emojiCategories = append(emojiCategories, emojiCategory)
+	}
+
+	return emojiCategories, nil
+}

internal/db/bundb/emoji_test.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/stretchr/testify/suite"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/testrig"
 )
 
 type EmojiTestSuite struct {
@@ -54,6 +55,8 @@ func (suite *EmojiTestSuite) TestGetEmojiByStaticURL() {
 	suite.NoError(err)
 	suite.NotNil(emoji)
 	suite.Equal("rainbow", emoji.Shortcode)
+	suite.NotNil(emoji.Category)
+	suite.Equal("reactions", emoji.Category.Name)
 }
 
 func (suite *EmojiTestSuite) TestGetAllEmojis() {
@@ -143,6 +146,21 @@ func (suite *EmojiTestSuite) TestGetSpecificEmojisFromDomain2() {
 	suite.Equal("yell", emojis[0].Shortcode)
 }
 
+func (suite *EmojiTestSuite) TestGetEmojiCategories() {
+	categories, err := suite.db.GetEmojiCategories(context.Background())
+	suite.NoError(err)
+	suite.Len(categories, 2)
+	// check alphabetical order
+	suite.Equal(categories[0].Name, "cute stuff")
+	suite.Equal(categories[1].Name, "reactions")
+}
+
+func (suite *EmojiTestSuite) TestGetEmojiCategory() {
+	category, err := suite.db.GetEmojiCategory(context.Background(), testrig.NewTestEmojiCategories()["reactions"].ID)
+	suite.NoError(err)
+	suite.NotNil(category)
+}
+
 func TestEmojiTestSuite(t *testing.T) {
 	suite.Run(t, new(EmojiTestSuite))
 }

internal/db/bundb/migrations/20221031145649_emoji_categories.go

@@ -0,0 +1,46 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package migrations
+
+import (
+	"context"
+
+	gtsmodel "github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/uptrace/bun"
+)
+
+func init() {
+	up := func(ctx context.Context, db *bun.DB) error {
+		if _, err := db.NewCreateTable().Model(&gtsmodel.EmojiCategory{}).IfNotExists().Exec(ctx); err != nil {
+			return err
+		}
+
+		return nil
+	}
+
+	down := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			return nil
+		})
+	}
+
+	if err := Migrations.Register(up, down); err != nil {
+		panic(err)
+	}
+}

internal/db/emoji.go

@@ -50,4 +50,12 @@ type Emoji interface {
 	GetEmojiByURI(ctx context.Context, uri string) (*gtsmodel.Emoji, Error)
 	// GetEmojiByStaticURL gets an emoji using the URL of the static version of the emoji image.
 	GetEmojiByStaticURL(ctx context.Context, imageStaticURL string) (*gtsmodel.Emoji, Error)
+	// PutEmojiCategory puts one new emoji category in the database.
+	PutEmojiCategory(ctx context.Context, emojiCategory *gtsmodel.EmojiCategory) Error
+	// GetEmojiCategories gets a slice of the names of all existing emoji categories.
+	GetEmojiCategories(ctx context.Context) ([]*gtsmodel.EmojiCategory, Error)
+	// GetEmojiCategory gets one emoji category by its id.
+	GetEmojiCategory(ctx context.Context, id string) (*gtsmodel.EmojiCategory, Error)
+	// GetEmojiCategoryByName gets one emoji category by its name.
+	GetEmojiCategoryByName(ctx context.Context, name string) (*gtsmodel.EmojiCategory, Error)
 }

internal/gtsmodel/emoji.go

@@ -22,24 +22,25 @@ import "time"
 
 // Emoji represents a custom emoji that's been uploaded through the admin UI or downloaded from a remote instance.
 type Emoji struct {
-	ID                     string    `validate:"required,ulid" bun:"type:CHAR(26),pk,nullzero,notnull,unique"`                                // id of this item in the database
+	ID                     string         `validate:"required,ulid" bun:"type:CHAR(26),pk,nullzero,notnull,unique"`                                // id of this item in the database
-	CreatedAt              time.Time `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // when was item created
+	CreatedAt              time.Time      `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // when was item created
-	UpdatedAt              time.Time `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // when was item last updated
+	UpdatedAt              time.Time      `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // when was item last updated
-	Shortcode              string    `validate:"required" bun:",nullzero,notnull,unique:domainshortcode"`                                     // String shortcode for this emoji -- the part that's between colons. This should be lowercase a-z_  eg., 'blob_hug' 'purple_heart' Must be unique with domain.
+	Shortcode              string         `validate:"required" bun:",nullzero,notnull,unique:domainshortcode"`                                     // String shortcode for this emoji -- the part that's between colons. This should be lowercase a-z_  eg., 'blob_hug' 'purple_heart' Must be unique with domain.
-	Domain                 string    `validate:"omitempty,fqdn" bun:",nullzero,unique:domainshortcode"`                                       // Origin domain of this emoji, eg 'example.org', 'queer.party'. empty string for local emojis.
+	Domain                 string         `validate:"omitempty,fqdn" bun:",nullzero,unique:domainshortcode"`                                       // Origin domain of this emoji, eg 'example.org', 'queer.party'. empty string for local emojis.
-	ImageRemoteURL         string    `validate:"required_without=ImageURL,omitempty,url" bun:",nullzero"`                                     // Where can this emoji be retrieved remotely? Null for local emojis.
+	ImageRemoteURL         string         `validate:"required_without=ImageURL,omitempty,url" bun:",nullzero"`                                     // Where can this emoji be retrieved remotely? Null for local emojis.
-	ImageStaticRemoteURL   string    `validate:"required_without=ImageStaticURL,omitempty,url" bun:",nullzero"`                               // Where can a static / non-animated version of this emoji be retrieved remotely? Null for local emojis.
+	ImageStaticRemoteURL   string         `validate:"required_without=ImageStaticURL,omitempty,url" bun:",nullzero"`                               // Where can a static / non-animated version of this emoji be retrieved remotely? Null for local emojis.
-	ImageURL               string    `validate:"required_without=ImageRemoteURL,required_without=Domain,omitempty,url" bun:",nullzero"`       // Where can this emoji be retrieved from the local server? Null for remote emojis.
+	ImageURL               string         `validate:"required_without=ImageRemoteURL,required_without=Domain,omitempty,url" bun:",nullzero"`       // Where can this emoji be retrieved from the local server? Null for remote emojis.
-	ImageStaticURL         string    `validate:"required_without=ImageStaticRemoteURL,required_without=Domain,omitempty,url" bun:",nullzero"` // Where can a static version of this emoji be retrieved from the local server? Null for remote emojis.
+	ImageStaticURL         string         `validate:"required_without=ImageStaticRemoteURL,required_without=Domain,omitempty,url" bun:",nullzero"` // Where can a static version of this emoji be retrieved from the local server? Null for remote emojis.
-	ImagePath              string    `validate:"required,file" bun:",nullzero,notnull"`                                                       // Path of the emoji image in the server storage system.
+	ImagePath              string         `validate:"required,file" bun:",nullzero,notnull"`                                                       // Path of the emoji image in the server storage system.
-	ImageStaticPath        string    `validate:"required,file" bun:",nullzero,notnull"`                                                       // Path of a static version of the emoji image in the server storage system
+	ImageStaticPath        string         `validate:"required,file" bun:",nullzero,notnull"`                                                       // Path of a static version of the emoji image in the server storage system
-	ImageContentType       string    `validate:"required" bun:",nullzero,notnull"`                                                            // MIME content type of the emoji image
+	ImageContentType       string         `validate:"required" bun:",nullzero,notnull"`                                                            // MIME content type of the emoji image
-	ImageStaticContentType string    `validate:"required" bun:",nullzero,notnull"`                                                            // MIME content type of the static version of the emoji image.
+	ImageStaticContentType string         `validate:"required" bun:",nullzero,notnull"`                                                            // MIME content type of the static version of the emoji image.
-	ImageFileSize          int       `validate:"required,min=1" bun:",nullzero,notnull"`                                                      // Size of the emoji image file in bytes, for serving purposes.
+	ImageFileSize          int            `validate:"required,min=1" bun:",nullzero,notnull"`                                                      // Size of the emoji image file in bytes, for serving purposes.
-	ImageStaticFileSize    int       `validate:"required,min=1" bun:",nullzero,notnull"`                                                      // Size of the static version of the emoji image file in bytes, for serving purposes.
+	ImageStaticFileSize    int            `validate:"required,min=1" bun:",nullzero,notnull"`                                                      // Size of the static version of the emoji image file in bytes, for serving purposes.
-	ImageUpdatedAt         time.Time `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // When was the emoji image last updated?
+	ImageUpdatedAt         time.Time      `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"`                         // When was the emoji image last updated?
-	Disabled               *bool     `validate:"-" bun:",nullzero,notnull,default:false"`                                                     // Has a moderation action disabled this emoji from being shown?
+	Disabled               *bool          `validate:"-" bun:",nullzero,notnull,default:false"`                                                     // Has a moderation action disabled this emoji from being shown?
-	URI                    string    `validate:"url" bun:",nullzero,notnull,unique"`                                                          // ActivityPub uri of this emoji. Something like 'https://example.org/emojis/1234'
+	URI                    string         `validate:"url" bun:",nullzero,notnull,unique"`                                                          // ActivityPub uri of this emoji. Something like 'https://example.org/emojis/1234'
-	VisibleInPicker        *bool     `validate:"-" bun:",nullzero,notnull,default:true"`                                                      // Is this emoji visible in the admin emoji picker?
+	VisibleInPicker        *bool          `validate:"-" bun:",nullzero,notnull,default:true"`                                                      // Is this emoji visible in the admin emoji picker?
-	CategoryID             string    `validate:"omitempty,ulid" bun:"type:CHAR(26),nullzero"`                                                 // In which emoji category is this emoji visible?
+	Category               *EmojiCategory `validate:"-" bun:"rel:belongs-to"`                                                                      // In which emoji category is this emoji visible?
+	CategoryID             string         `validate:"omitempty,ulid" bun:"type:CHAR(26),nullzero"`                                                 // ID of the category this emoji belongs to.
 }

internal/gtsmodel/emojicategory.go

@@ -0,0 +1,29 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package gtsmodel
+
+import "time"
+
+// EmojiCategory represents a grouping of custom emojis.
+type EmojiCategory struct {
+	ID        string    `validate:"required,ulid" bun:"type:CHAR(26),pk,nullzero,notnull,unique"`        // id of this item in the database
+	CreatedAt time.Time `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"` // when was item created
+	UpdatedAt time.Time `validate:"-" bun:"type:timestamptz,nullzero,notnull,default:current_timestamp"` // when was item last updated
+	Name      string    `validate:"required" bun:",nullzero,notnull,unique"`                             // name of this category
+}

internal/processing/admin.go

@@ -46,6 +46,10 @@ func (p *processor) AdminEmojiDelete(ctx context.Context, authed *oauth.Auth, id
 	return p.adminProcessor.EmojiDelete(ctx, id)
 }
 
+func (p *processor) AdminEmojiCategoriesGet(ctx context.Context) ([]*apimodel.EmojiCategory, gtserror.WithCode) {
+	return p.adminProcessor.EmojiCategoriesGet(ctx)
+}
+
 func (p *processor) AdminDomainBlockCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) (*apimodel.DomainBlock, gtserror.WithCode) {
 	return p.adminProcessor.DomainBlockCreate(ctx, authed.Account, form.Domain, form.Obfuscate, form.PublicComment, form.PrivateComment, "")
 }

internal/processing/admin/admin.go

@@ -44,6 +44,7 @@ type Processor interface {
 	EmojisGet(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, domain string, includeDisabled bool, includeEnabled bool, shortcode string, maxShortcodeDomain string, minShortcodeDomain string, limit int) (*apimodel.PageableResponse, gtserror.WithCode)
 	EmojiGet(ctx context.Context, account *gtsmodel.Account, user *gtsmodel.User, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
 	EmojiDelete(ctx context.Context, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
+	EmojiCategoriesGet(ctx context.Context) ([]*apimodel.EmojiCategory, gtserror.WithCode)
 	MediaPrune(ctx context.Context, mediaRemoteCacheDays int) gtserror.WithCode
 }
 

internal/processing/admin/createemoji.go

@@ -28,6 +28,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/id"
+	"github.com/superseriousbusiness/gotosocial/internal/media"
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
@@ -57,7 +58,19 @@ func (p *processor) EmojiCreate(ctx context.Context, account *gtsmodel.Account,
 		return f, form.Image.Size, err
 	}
 
-	processingEmoji, err := p.mediaManager.ProcessEmoji(ctx, data, nil, form.Shortcode, emojiID, emojiURI, nil, false)
+	var ai *media.AdditionalEmojiInfo
+	if form.CategoryName != "" {
+		category, err := p.GetOrCreateEmojiCategory(ctx, form.CategoryName)
+		if err != nil {
+			return nil, gtserror.NewErrorInternalError(fmt.Errorf("error putting id in category: %s", err), "error putting id in category")
+		}
+
+		ai = &media.AdditionalEmojiInfo{
+			CategoryID: &category.ID,
+		}
+	}
+
+	processingEmoji, err := p.mediaManager.ProcessEmoji(ctx, data, nil, form.Shortcode, emojiID, emojiURI, ai, false)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error processing emoji: %s", err), "error processing emoji")
 	}

internal/processing/admin/emojicategory.go

@@ -0,0 +1,60 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package admin
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/id"
+)
+
+func (p *processor) GetOrCreateEmojiCategory(ctx context.Context, name string) (*gtsmodel.EmojiCategory, error) {
+	category, err := p.db.GetEmojiCategoryByName(ctx, name)
+	if err == nil {
+		return category, nil
+	}
+
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		err = fmt.Errorf("GetOrCreateEmojiCategory: database error trying get emoji category by name: %s", err)
+		return nil, err
+	}
+
+	// we don't have the category yet, just create it with the given name
+	categoryID, err := id.NewRandomULID()
+	if err != nil {
+		err = fmt.Errorf("GetOrCreateEmojiCategory: error generating id for new emoji category: %s", err)
+		return nil, err
+	}
+
+	category = &gtsmodel.EmojiCategory{
+		ID:   categoryID,
+		Name: name,
+	}
+
+	if err := p.db.PutEmojiCategory(ctx, category); err != nil {
+		err = fmt.Errorf("GetOrCreateEmojiCategory: error putting new emoji category in the database: %s", err)
+		return nil, err
+	}
+
+	return category, nil
+}

internal/processing/admin/getcategories.go

@@ -0,0 +1,47 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package admin
+
+import (
+	"context"
+	"fmt"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+)
+
+func (p *processor) EmojiCategoriesGet(ctx context.Context) ([]*apimodel.EmojiCategory, gtserror.WithCode) {
+	categories, err := p.db.GetEmojiCategories(ctx)
+	if err != nil {
+		err := fmt.Errorf("EmojiCategoriesGet: db error: %s", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	apiCategories := make([]*apimodel.EmojiCategory, 0, len(categories))
+	for _, category := range categories {
+		apiCategory, err := p.tc.EmojiCategoryToAPIEmojiCategory(ctx, category)
+		if err != nil {
+			err := fmt.Errorf("EmojiCategoriesGet: error converting emoji category to api emoji category: %s", err)
+			return nil, gtserror.NewErrorInternalError(err)
+		}
+		apiCategories = append(apiCategories, apiCategory)
+	}
+
+	return apiCategories, nil
+}

internal/processing/processor.go

@@ -119,6 +119,8 @@ type Processor interface {
 	// AdminEmojiDelete deletes one *local* emoji with the given key. Remote emojis will not be deleted this way.
 	// Only admin users in good standing should be allowed to access this function -- check this before calling it.
 	AdminEmojiDelete(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
+	// AdminEmojiCategoriesGet gets a list of all existing emoji categories.
+	AdminEmojiCategoriesGet(ctx context.Context) ([]*apimodel.EmojiCategory, gtserror.WithCode)
 	// AdminDomainBlockCreate handles the creation of a new domain block by an admin, using the given form.
 	AdminDomainBlockCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) (*apimodel.DomainBlock, gtserror.WithCode)
 	// AdminDomainBlocksImport handles the import of multiple domain blocks by an admin, using the given form.

internal/typeutils/converter.go

@@ -69,6 +69,8 @@ type TypeConverter interface {
 	EmojiToAPIEmoji(ctx context.Context, e *gtsmodel.Emoji) (model.Emoji, error)
 	// EmojiToAdminAPIEmoji converts a gts model emoji into an API representation with extra admin information.
 	EmojiToAdminAPIEmoji(ctx context.Context, e *gtsmodel.Emoji) (*model.AdminEmoji, error)
+	// EmojiCategoryToAPIEmojiCategory converts a gts model emoji category into its api (frontend) representation.
+	EmojiCategoryToAPIEmojiCategory(ctx context.Context, category *gtsmodel.EmojiCategory) (*model.EmojiCategory, error)
 	// TagToAPITag converts a gts model tag into its api (frontend) representation for serialization on the API.
 	TagToAPITag(ctx context.Context, t *gtsmodel.Tag) (model.Tag, error)
 	// StatusToAPIStatus converts a gts model status into its api (frontend) representation for serialization on the API.

internal/typeutils/internaltofrontend.go

@@ -356,12 +356,24 @@ func (c *converter) MentionToAPIMention(ctx context.Context, m *gtsmodel.Mention
 }
 
 func (c *converter) EmojiToAPIEmoji(ctx context.Context, e *gtsmodel.Emoji) (model.Emoji, error) {
+	var category string
+	if e.CategoryID != "" {
+		if e.Category == nil {
+			var err error
+			e.Category, err = c.db.GetEmojiCategory(ctx, e.CategoryID)
+			if err != nil {
+				return model.Emoji{}, err
+			}
+		}
+		category = e.Category.Name
+	}
+
 	return model.Emoji{
 		Shortcode:       e.Shortcode,
 		URL:             e.ImageURL,
 		StaticURL:       e.ImageStaticURL,
 		VisibleInPicker: *e.VisibleInPicker,
-		Category:        e.CategoryID,
+		Category:        category,
 	}, nil
 }
 
@@ -383,6 +395,13 @@ func (c *converter) EmojiToAdminAPIEmoji(ctx context.Context, e *gtsmodel.Emoji)
 	}, nil
 }
 
+func (c *converter) EmojiCategoryToAPIEmojiCategory(ctx context.Context, category *gtsmodel.EmojiCategory) (*model.EmojiCategory, error) {
+	return &model.EmojiCategory{
+		ID:   category.ID,
+		Name: category.Name,
+	}, nil
+}
+
 func (c *converter) TagToAPITag(ctx context.Context, t *gtsmodel.Tag) (model.Tag, error) {
 	return model.Tag{
 		Name: t.Name,

internal/typeutils/internaltofrontend_test.go

@@ -55,7 +55,7 @@ func (suite *InternalToFrontendTestSuite) TestAccountToFrontendWithEmojiStruct()
 
 	b, err := json.Marshal(apiAccount)
 	suite.NoError(err)
-	suite.Equal(`{"id":"01F8MH1H7YV1Z7D2C8K2730QBF","username":"the_mighty_zork","acct":"the_mighty_zork","display_name":"original zork (he/they)","locked":false,"bot":false,"created_at":"2022-05-20T11:09:18.000Z","note":"\u003cp\u003ehey yo this is my profile!\u003c/p\u003e","url":"http://localhost:8080/@the_mighty_zork","avatar":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/original/01F8MH58A357CV5K7R7TJMSH6S.jpeg","avatar_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/small/01F8MH58A357CV5K7R7TJMSH6S.jpeg","header":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/original/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","header_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/small/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","followers_count":2,"following_count":2,"statuses_count":5,"last_status_at":"2022-05-20T11:37:55.000Z","emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true}],"fields":[],"enable_rss":true}`, string(b))
+	suite.Equal(`{"id":"01F8MH1H7YV1Z7D2C8K2730QBF","username":"the_mighty_zork","acct":"the_mighty_zork","display_name":"original zork (he/they)","locked":false,"bot":false,"created_at":"2022-05-20T11:09:18.000Z","note":"\u003cp\u003ehey yo this is my profile!\u003c/p\u003e","url":"http://localhost:8080/@the_mighty_zork","avatar":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/original/01F8MH58A357CV5K7R7TJMSH6S.jpeg","avatar_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/small/01F8MH58A357CV5K7R7TJMSH6S.jpeg","header":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/original/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","header_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/small/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","followers_count":2,"following_count":2,"statuses_count":5,"last_status_at":"2022-05-20T11:37:55.000Z","emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions"}],"fields":[],"enable_rss":true}`, string(b))
 }
 
 func (suite *InternalToFrontendTestSuite) TestAccountToFrontendWithEmojiIDs() {
@@ -70,7 +70,7 @@ func (suite *InternalToFrontendTestSuite) TestAccountToFrontendWithEmojiIDs() {
 
 	b, err := json.Marshal(apiAccount)
 	suite.NoError(err)
-	suite.Equal(`{"id":"01F8MH1H7YV1Z7D2C8K2730QBF","username":"the_mighty_zork","acct":"the_mighty_zork","display_name":"original zork (he/they)","locked":false,"bot":false,"created_at":"2022-05-20T11:09:18.000Z","note":"\u003cp\u003ehey yo this is my profile!\u003c/p\u003e","url":"http://localhost:8080/@the_mighty_zork","avatar":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/original/01F8MH58A357CV5K7R7TJMSH6S.jpeg","avatar_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/small/01F8MH58A357CV5K7R7TJMSH6S.jpeg","header":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/original/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","header_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/small/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","followers_count":2,"following_count":2,"statuses_count":5,"last_status_at":"2022-05-20T11:37:55.000Z","emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true}],"fields":[],"enable_rss":true}`, string(b))
+	suite.Equal(`{"id":"01F8MH1H7YV1Z7D2C8K2730QBF","username":"the_mighty_zork","acct":"the_mighty_zork","display_name":"original zork (he/they)","locked":false,"bot":false,"created_at":"2022-05-20T11:09:18.000Z","note":"\u003cp\u003ehey yo this is my profile!\u003c/p\u003e","url":"http://localhost:8080/@the_mighty_zork","avatar":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/original/01F8MH58A357CV5K7R7TJMSH6S.jpeg","avatar_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/avatar/small/01F8MH58A357CV5K7R7TJMSH6S.jpeg","header":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/original/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","header_static":"http://localhost:8080/fileserver/01F8MH1H7YV1Z7D2C8K2730QBF/header/small/01PFPMWK2FF0D9WMHEJHR07C3Q.jpeg","followers_count":2,"following_count":2,"statuses_count":5,"last_status_at":"2022-05-20T11:37:55.000Z","emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions"}],"fields":[],"enable_rss":true}`, string(b))
 }
 
 func (suite *InternalToFrontendTestSuite) TestAccountToFrontendSensitive() {
@@ -93,7 +93,7 @@ func (suite *InternalToFrontendTestSuite) TestStatusToFrontend() {
 	b, err := json.Marshal(apiStatus)
 	suite.NoError(err)
 
-	suite.Equal(`{"id":"01F8MH75CBF9JFX4ZAD54N0W0R","created_at":"2021-10-20T11:36:45.000Z","in_reply_to_id":null,"in_reply_to_account_id":null,"sensitive":false,"spoiler_text":"","visibility":"public","language":"en","uri":"http://localhost:8080/users/admin/statuses/01F8MH75CBF9JFX4ZAD54N0W0R","url":"http://localhost:8080/@admin/statuses/01F8MH75CBF9JFX4ZAD54N0W0R","replies_count":0,"reblogs_count":0,"favourites_count":1,"favourited":true,"reblogged":false,"muted":false,"bookmarked":false,"pinned":false,"content":"hello world! #welcome ! first post on the instance :rainbow: !","reblog":null,"application":{"name":"superseriousbusiness","website":"https://superserious.business"},"account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"media_attachments":[{"id":"01F8MH6NEM8D7527KZAECTCR76","type":"image","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/original/01F8MH6NEM8D7527KZAECTCR76.jpeg","text_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/original/01F8MH6NEM8D7527KZAECTCR76.jpeg","preview_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/small/01F8MH6NEM8D7527KZAECTCR76.jpeg","remote_url":null,"preview_remote_url":null,"meta":{"original":{"width":1200,"height":630,"size":"1200x630","aspect":1.9047619},"small":{"width":256,"height":134,"size":"256x134","aspect":1.9104477},"focus":{"x":0,"y":0}},"description":"Black and white image of some 50's style text saying: Welcome On Board","blurhash":"LNJRdVM{00Rj%Mayt7j[4nWBofRj"}],"mentions":[],"tags":[{"name":"welcome","url":"http://localhost:8080/tags/welcome"}],"emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true}],"card":null,"poll":null,"text":"hello world! #welcome ! first post on the instance :rainbow: !"}`, string(b))
+	suite.Equal(`{"id":"01F8MH75CBF9JFX4ZAD54N0W0R","created_at":"2021-10-20T11:36:45.000Z","in_reply_to_id":null,"in_reply_to_account_id":null,"sensitive":false,"spoiler_text":"","visibility":"public","language":"en","uri":"http://localhost:8080/users/admin/statuses/01F8MH75CBF9JFX4ZAD54N0W0R","url":"http://localhost:8080/@admin/statuses/01F8MH75CBF9JFX4ZAD54N0W0R","replies_count":0,"reblogs_count":0,"favourites_count":1,"favourited":true,"reblogged":false,"muted":false,"bookmarked":false,"pinned":false,"content":"hello world! #welcome ! first post on the instance :rainbow: !","reblog":null,"application":{"name":"superseriousbusiness","website":"https://superserious.business"},"account":{"id":"01F8MH17FWEB39HZJ76B6VXSKF","username":"admin","acct":"admin","display_name":"","locked":false,"bot":false,"created_at":"2022-05-17T13:10:59.000Z","note":"","url":"http://localhost:8080/@admin","avatar":"","avatar_static":"","header":"http://localhost:8080/assets/default_header.png","header_static":"http://localhost:8080/assets/default_header.png","followers_count":1,"following_count":1,"statuses_count":4,"last_status_at":"2021-10-20T10:41:37.000Z","emojis":[],"fields":[],"enable_rss":true},"media_attachments":[{"id":"01F8MH6NEM8D7527KZAECTCR76","type":"image","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/original/01F8MH6NEM8D7527KZAECTCR76.jpeg","text_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/original/01F8MH6NEM8D7527KZAECTCR76.jpeg","preview_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/attachment/small/01F8MH6NEM8D7527KZAECTCR76.jpeg","remote_url":null,"preview_remote_url":null,"meta":{"original":{"width":1200,"height":630,"size":"1200x630","aspect":1.9047619},"small":{"width":256,"height":134,"size":"256x134","aspect":1.9104477},"focus":{"x":0,"y":0}},"description":"Black and white image of some 50's style text saying: Welcome On Board","blurhash":"LNJRdVM{00Rj%Mayt7j[4nWBofRj"}],"mentions":[],"tags":[{"name":"welcome","url":"http://localhost:8080/tags/welcome"}],"emojis":[{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions"}],"card":null,"poll":null,"text":"hello world! #welcome ! first post on the instance :rainbow: !"}`, string(b))
 }
 
 func (suite *InternalToFrontendTestSuite) TestInstanceToFrontend() {
@@ -148,7 +148,7 @@ func (suite *InternalToFrontendTestSuite) TestEmojiToFrontend() {
 	b, err := json.Marshal(emoji)
 	suite.NoError(err)
 
-	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true}`, string(b))
+	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions"}`, string(b))
 }
 
 func (suite *InternalToFrontendTestSuite) TestEmojiToFrontendAdmin1() {
@@ -158,7 +158,7 @@ func (suite *InternalToFrontendTestSuite) TestEmojiToFrontendAdmin1() {
 	b, err := json.Marshal(emoji)
 	suite.NoError(err)
 
-	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
+	suite.Equal(`{"shortcode":"rainbow","url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/original/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","static_url":"http://localhost:8080/fileserver/01F8MH17FWEB39HZJ76B6VXSKF/emoji/static/01F8MH9H8E4VG3KDYJR9EGPXCQ.png","visible_in_picker":true,"category":"reactions","id":"01F8MH9H8E4VG3KDYJR9EGPXCQ","disabled":false,"updated_at":"2021-09-20T10:40:37.000Z","total_file_size":47115,"content_type":"image/png","uri":"http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ"}`, string(b))
 }
 
 func (suite *InternalToFrontendTestSuite) TestEmojiToFrontendAdmin2() {

internal/validate/formvalidation.go

@@ -42,6 +42,7 @@ const (
 	maximumSiteTermsLength        = 5000
 	maximumUsernameLength         = 64
 	maximumCustomCSSLength        = 5000
+	maximumEmojiCategoryLength    = 64
 )
 
 // NewPassword returns an error if the given password is not sufficiently strong, or nil if it's ok.
@@ -182,6 +183,14 @@ func EmojiShortcode(shortcode string) error {
 	return nil
 }
 
+// EmojiCategory validates the length of the given category string.
+func EmojiCategory(category string) error {
+	if length := len(category); length > maximumEmojiCategoryLength {
+		return fmt.Errorf("emoji category %s did not pass validation, must be less than %d characters, but provided value was %d characters", category, maximumEmojiCategoryLength, length)
+	}
+	return nil
+}
+
 // SiteTitle ensures that the given site title is within spec.
 func SiteTitle(siteTitle string) error {
 	if length := len([]rune(siteTitle)); length > maximumSiteTitleLength {

testrig/db.go

@@ -55,6 +55,7 @@ var testModels = []interface{}{
 	&gtsmodel.RouterSession{},
 	&gtsmodel.Token{},
 	&gtsmodel.Client{},
+	&gtsmodel.EmojiCategory{},
 	&gtsmodel.Tombstone{},
 }
 
@@ -199,6 +200,12 @@ func StandardDBSetup(db db.DB, accounts map[string]*gtsmodel.Account) {
 		}
 	}
 
+	for _, v := range NewTestEmojiCategories() {
+		if err := db.Put(ctx, v); err != nil {
+			log.Panic(err)
+		}
+	}
+
 	for _, v := range NewTestStatusToEmojis() {
 		if err := db.Put(ctx, v); err != nil {
 			log.Panic(err)

testrig/testmodels.go

@@ -964,7 +964,7 @@ func NewTestEmojis() map[string]*gtsmodel.Emoji {
 			Disabled:               FalseBool(),
 			URI:                    "http://localhost:8080/emoji/01F8MH9H8E4VG3KDYJR9EGPXCQ",
 			VisibleInPicker:        TrueBool(),
-			CategoryID:             "",
+			CategoryID:             "01GGQ8V4993XK67B2JB396YFB7",
 		},
 		"yell": {
 			ID:                     "01GD5KP5CQEE1R3X43Y1EHS2CW",
@@ -991,6 +991,23 @@ func NewTestEmojis() map[string]*gtsmodel.Emoji {
 	}
 }
 
+func NewTestEmojiCategories() map[string]*gtsmodel.EmojiCategory {
+	return map[string]*gtsmodel.EmojiCategory{
+		"reactions": {
+			ID:        "01GGQ8V4993XK67B2JB396YFB7",
+			Name:      "reactions",
+			CreatedAt: TimeMustParse("2020-03-18T11:40:55+02:00"),
+			UpdatedAt: TimeMustParse("2020-03-19T12:35:12+02:00"),
+		},
+		"cute stuff": {
+			ID:        "01GGQ989PTT9PMRN4FZ1WWK2B9",
+			Name:      "cute stuff",
+			CreatedAt: TimeMustParse("2020-03-20T11:40:55+02:00"),
+			UpdatedAt: TimeMustParse("2020-03-21T12:35:12+02:00"),
+		},
+	}
+}
+
 func NewTestStatusToEmojis() map[string]*gtsmodel.StatusToEmoji {
 	return map[string]*gtsmodel.StatusToEmoji{
 		"admin_account_status_1_rainbow": {