4 files changed, 54 insertions, 6 deletions

diff --git a/server/middlewares/doc.ts b/server/middlewares/doc.ts
new file mode 100644
index 000000000..aa852cd77
--- /dev/null
+++ b/server/middlewares/doc.ts
@@ -0,0 +1,13 @@
+import * as express from 'express'
+
+function docMiddleware (docUrl: string) {
+  return (req: express.Request, res: express.Response, next: express.NextFunction) => {
+    res.locals.docUrl = docUrl
+
+    if (next) return next()
+  }
+}
+
+export {
+  docMiddleware
+}
diff --git a/server/middlewares/error.ts b/server/middlewares/error.ts
new file mode 100644
index 000000000..e3eb1c8f5
--- /dev/null
+++ b/server/middlewares/error.ts
@@ -0,0 +1,39 @@
+import * as express from 'express'
+import { ProblemDocument, ProblemDocumentExtension } from 'http-problem-details'
+import { HttpStatusCode } from '@shared/core-utils'
+
+function apiFailMiddleware (req: express.Request, res: express.Response, next: express.NextFunction) {
+  res.fail = options => {
+    const { status = HttpStatusCode.BAD_REQUEST_400, message, title, type, data, instance } = options
+
+    const extension = new ProblemDocumentExtension({
+      ...data,
+
+      docs: res.locals.docUrl,
+      code: type,
+
+      // For <= 3.2 compatibility
+      error: message
+    })
+
+    res.status(status)
+    res.setHeader('Content-Type', 'application/problem+json')
+    res.json(new ProblemDocument({
+      status,
+      title,
+      instance,
+
+      detail: message,
+
+      type: type
+        ? `https://docs.joinpeertube.org/api-rest-reference.html#section/Errors/${type}`
+        : undefined
+    }, extension))
+  }
+
+  if (next) next()
+}
+
+export {
+  apiFailMiddleware
+}
diff --git a/server/middlewares/index.ts b/server/middlewares/index.ts
index 3e280e16f..413653dac 100644
--- a/server/middlewares/index.ts
+++ b/server/middlewares/index.ts
@@ -7,4 +7,6 @@ export * from './servers'
 export * from './sort'
 export * from './user-right'
 export * from './dnt'
+export * from './error'
+export * from './doc'
 export * from './csp'
diff --git a/server/middlewares/validators/videos/videos.ts b/server/middlewares/validators/videos/videos.ts
index 64e09234e..b7a9bcbe3 100644
--- a/server/middlewares/validators/videos/videos.ts
+++ b/server/middlewares/validators/videos/videos.ts
@@ -73,7 +73,6 @@ const videosAddLegacyValidator = getCommonVideoEditAttributes().concat([
     .custom(isIdValid).withMessage('Should have correct video channel id'),
 
   async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-    res.docs = "https://docs.joinpeertube.org/api-rest-reference.html#operation/uploadLegacy"
     logger.debug('Checking videosAdd parameters', { parameters: req.body, files: req.files })
 
     if (areValidationErrors(req, res)) return cleanUpReqFiles(req)
@@ -108,7 +107,6 @@ const videosAddLegacyValidator = getCommonVideoEditAttributes().concat([
  */
 const videosAddResumableValidator = [
   async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-    res.docs = "https://docs.joinpeertube.org/api-rest-reference.html#operation/uploadResumable"
     const user = res.locals.oauth.token.User
 
     const body: express.CustomUploadXFile<express.UploadXFileMetadata> = req.body
@@ -170,7 +168,6 @@ const videosAddResumableInitValidator = getCommonVideoEditAttributes().concat([
     .withMessage('Should specify the file mimetype'),
 
   async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-    res.docs = "https://docs.joinpeertube.org/api-rest-reference.html#operation/uploadResumableInit"
     const videoFileMetadata = {
       mimetype: req.headers['x-upload-content-type'] as string,
       size: +req.headers['x-upload-content-length'],
@@ -214,7 +211,6 @@ const videosUpdateValidator = getCommonVideoEditAttributes().concat([
     .custom(isIdValid).withMessage('Should have correct video channel id'),
 
   async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-    res.docs = 'https://docs.joinpeertube.org/api-rest-reference.html#operation/putVideo'
     logger.debug('Checking videosUpdate parameters', { parameters: req.body })
 
     if (areValidationErrors(req, res)) return cleanUpReqFiles(req)
@@ -268,7 +264,6 @@ const videosCustomGetValidator = (
     param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),
 
     async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-      res.docs = 'https://docs.joinpeertube.org/api-rest-reference.html#operation/getVideo'
       logger.debug('Checking videosGet parameters', { parameters: req.params })
 
       if (areValidationErrors(req, res)) return
@@ -334,7 +329,6 @@ const videosRemoveValidator = [
   param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),
 
   async (req: express.Request, res: express.Response, next: express.NextFunction) => {
-    res.docs = "https://docs.joinpeertube.org/api-rest-reference.html#operation/delVideo"
     logger.debug('Checking videosRemove parameters', { parameters: req.params })
 
     if (areValidationErrors(req, res)) return