diff --git a/server/tests/utils/miscs/miscs.ts b/server/tests/utils/miscs/miscs.ts
index e6666619b..f93e2372e 100644
--- a/server/tests/utils/miscs/miscs.ts
+++ b/server/tests/utils/miscs/miscs.ts
@@ -1,5 +1,10 @@
+/* tslint:disable:no-unused-expression */
+
+import { expect } from 'chai'
 import { join } from 'path'
+import * as request from 'supertest'
 import * as WebTorrent from 'webtorrent'
+import { readFileBufferPromise } from '../../../helpers/core-utils'
 
 let webtorrent = new WebTorrent()
 
@@ -30,6 +35,27 @@ function root () {
   return join(__dirname, '..', '..', '..', '..')
 }
 
+async function testImage (url: string, imageName: string, imagePath: string, extension = '.jpg') {
+  // Don't test images if the node env is not set
+  // Because we need a special ffmpeg version for this test
+  if (process.env[ 'NODE_TEST_IMAGE' ]) {
+    const res = await request(url)
+      .get(imagePath)
+      .expect(200)
+
+    const body = res.body
+
+    const data = await readFileBufferPromise(join(__dirname, '..', '..', 'api', 'fixtures', imageName + extension))
+    const minLength = body.length - ((50 * body.length) / 100)
+    const maxLength = body.length + ((50 * body.length) / 100)
+
+    return data.length > minLength && data.length < maxLength
+  } else {
+    console.log('Do not test images. Enable it by setting NODE_TEST_IMAGE env variable.')
+    return true
+  }
+}
+
 // ---------------------------------------------------------------------------
 
 export {
@@ -37,5 +63,6 @@ export {
   wait,
   webtorrentAdd,
   immutableAssign,
+  testImage,
   root
 }
diff --git a/server/tests/utils/videos/videos.ts b/server/tests/utils/videos/videos.ts
index 270a6042b..605acf565 100644
--- a/server/tests/utils/videos/videos.ts
+++ b/server/tests/utils/videos/videos.ts
@@ -5,7 +5,7 @@ import { existsSync, readFile } from 'fs'
 import * as parseTorrent from 'parse-torrent'
 import { extname, isAbsolute, join } from 'path'
 import * as request from 'supertest'
-import { getMyUserInformation, makeGetRequest, root, ServerInfo } from '../'
+import { getMyUserInformation, makeGetRequest, root, ServerInfo, testImage } from '../'
 import { VideoPrivacy } from '../../../../shared/models/videos'
 import { readdirPromise, readFileBufferPromise } from '../../../helpers/core-utils'
 import { VIDEO_CATEGORIES, VIDEO_LANGUAGES, VIDEO_LICENCES, VIDEO_PRIVACIES } from '../../../initializers'
@@ -219,23 +219,6 @@ async function checkVideoFilesWereRemoved (videoUUID: string, serverNumber: numb
   }
 }
 
-async function testImage (url: string, imageName: string, imagePath: string, extension = '.jpg') {
-  // Don't test images if the node env is not set
-  // Because we need a special ffmpeg version for this test
-  if (process.env['NODE_TEST_IMAGE']) {
-    const res = await request(url)
-                        .get(imagePath)
-                        .expect(200)
-
-    const data = await readFileBufferPromise(join(__dirname, '..', '..', 'api', 'fixtures', imageName + extension))
-
-    return data.equals(res.body)
-  } else {
-    console.log('Do not test images. Enable it by setting NODE_TEST_IMAGE env variable.')
-    return true
-  }
-}
-
 async function uploadVideo (url: string, accessToken: string, videoAttributesArg: VideoAttributes, specialStatus = 200) {
   const path = '/api/v1/videos/upload'
   let defaultChannelId = '1'
@@ -453,7 +436,6 @@ export {
   searchVideo,
   searchVideoWithPagination,
   searchVideoWithSort,
-  testImage,
   uploadVideo,
   updateVideo,
   rateVideo,
diff --git a/openapi.yaml b/support/doc/api/openapi.yaml
similarity index 100%
rename from openapi.yaml
rename to support/doc/api/openapi.yaml