feat: Add RFC error messages

Signed-off-by: Florian BOUILLON <f.bouillon@aptatio.com>

package-lock.json

@@ -1,5 +1,5 @@
 {
-	"name": "3dprint-time-estimator",
+	"name": "fi3d-slicer-as-a-service",
 	"lockfileVersion": 2,
 	"requires": true,
 	"packages": {

src/HTTPError.ts

@@ -0,0 +1,54 @@
+import { Response } from 'express'
+
+/**
+ * An error as of the RFC7807
+ * 
+ * you MUST send the content-type `application/problem+json`
+ */
+export default interface HTTPError extends Record<string, any> {
+	/**
+	 * A URI reference [RFC3986] that identifies the
+	 * problem type.  This specification encourages that, when
+	 * dereferenced, it provide human-readable documentation for the
+	 * problem type (e.g., using HTML [W3C.REC-html5-20141028]).  When
+	 * this member is not present, its value is assumed to be
+	 * "about:blank".
+	 */
+	title: string
+	/**
+	 * A short, human-readable summary of the problem
+	 * type.  It SHOULD NOT change from occurrence to occurrence of the
+	 * problem, except for purposes of localization (e.g., using
+	 * proactive content negotiation; see [RFC7231], Section 3.4).
+	 */
+	type?: string
+
+	/**
+	 * The HTTP status code ([RFC7231], Section 6)
+	 * generated by the origin server for this occurrence of the problem.
+	 */
+	status?: number
+
+	/**
+	 * A human-readable explanation specific to this
+	 * occurrence of the problem.
+	 */
+	detail?: string
+
+
+	/**
+	 * A URI reference that identifies the specific
+	 * occurrence of the problem.  It may or may not yield further
+	 * information if dereferenced.
+	 */
+	instance?: string
+}
+
+export function createErrorResponse(res: Response, error: HTTPError) {
+	res.status(error.status ?? 500)
+	if (!error.type) {
+		error.type = 'about:blank'
+	}
+	res.setHeader('Content-Type', 'application/problem+json')
+	res.json(error)
+}

src/main.ts

@@ -1,10 +1,11 @@
+import { objectMap, objectOmit } from '@dzeio/object-util'
+import { exec as execAsync } from 'child_process'
 import express from 'express'
 import fs from 'fs/promises'
-import { exec as execAsync } from 'child_process'
-import { objectMap, objectOmit } from '@dzeio/object-util'
-import { getParams } from './gcodeUtils'
-import util from 'util'
 import { evaluate } from 'mathjs'
+import util from 'util'
+import { createErrorResponse } from './HTTPError'
+import { getParams } from './gcodeUtils'
 
 const exec = util.promisify(execAsync)
 const server = express()
@@ -48,8 +49,12 @@ server.post('/', async (req, res) => {
 	let config = `${path}/configs/` + (req.query?.config ?? 'config') + '.ini'
 	if (!exists(config)) {
 		console.log('request finished in error :(', file)
-		res.status(403).send('Configuration file not existing')
+		return createErrorResponse(res, {
-		return
+			title: 'Configuration file does not exist',
+			status: 404,
+			detail: `The configuration file you want to use does not exist`,
+			config: req.query?.config ?? 'config'
+		})
 	}
 	const stlPath = `${path}/files/${file}.stl`
 	const gcodePath = `${path}/files/${file}.gcode`
@@ -74,23 +79,50 @@ server.post('/', async (req, res) => {
 		console.error(e)
 		if (line.includes('Objects could not fit on the bed')) {
 			await fs.rm(stlPath)
-			res.status(403).send('Object is too large')
+			return createErrorResponse(res, {
-			return
+				title: 'Object is too large to fit on the bed',
+				status: 413,
+				detail: `The object you are trying to slice is too large to fit on the current bed`
+			})
 		} else if (line.includes('No such file')) {
 			await fs.rm(stlPath)
-			res.status(403).send('Configuration file not existing')
+			return createErrorResponse(res, {
-			return
+				title: 'Configuration file does not exist',
+				status: 404,
+				detail: `The configuration file you want to use does not exist`,
+				config: req.query?.config ?? 'config'
+			})
 		} else if (line.includes('Unknown option')) {
 			await fs.rm(stlPath)
-			res.status(403).send('an override does not exists, please contact an administrator or refer to the documentation')
+			return createErrorResponse(res, {
-			return
+				title: 'An override does exist',
+				status: 404,
+				detail: `One or more of your overrides are not available in the current slicer`,
+				overrides: overrides
+
+			})
 		} else if (line.includes('ETIMEDOUT') || line.includes('Command failed')) {
 			await fs.rm(stlPath)
-			res.status(403).send('the file is taking too long to process :(')
+			return createErrorResponse(res, {
-			return
+				title: 'File is taking too long to process',
+				status: 400,
+				detail: `The file you are trying to process is too large (${req.body.length}o) to be processed in less than 60 secs`,
+				fileId: file,
+				config: req.query?.config ?? 'config',
+				fileSize: req.body.length,
+				overrides: overrides
+			})
 		}
-		res.status(500).send(`Error while making the file:<br />${e.toString().replace(cmd, '<i>software</i>').replace(stlPath, `<i>file ${file}</i>`).replace(`${path}/configs/`, '').replace('.ini', '')}`)
+		return createErrorResponse(res, {
-		return
+			title: 'General I/O error',
+			status: 500,
+			detail: `A server error make it impossible to slice the file`,
+			fileId: file,
+			config: req.query?.config ?? 'config',
+			fileSize: req.body.length,
+			overrides: overrides,
+			serverMessage: e.toString().replace(cmd, '<i>software</i>').replace(stlPath, `<i>file ${file}</i>`).replace(`${path}/configs/`, '').replace('.ini', '')
+		})
 	}
 	const gcode = await fs.readFile(gcodePath, 'utf-8')
 	await fs.rm(stlPath)