Do not raise an error when a service is already started

src/commands/service/start.ts

@@ -2,6 +2,7 @@ import {flags} from '@oclif/command'
 import {InstanceCreateOutputs} from 'mesg-js/lib/api'
 
 import Command from '../../root-command'
+import {errorConversion} from '../../utils/error'
 import serviceResolver from '../../utils/service-resolver'
 
 export default class ServiceStart extends Command {
@@ -25,12 +26,16 @@ export default class ServiceStart extends Command {
     const {args, flags} = this.parse(ServiceStart)
     this.spinner.start('Start instance')
     const serviceHash = await serviceResolver(this.api, args.SERVICE_HASH)
-    const instance = await this.api.instance.create({
-      serviceHash,
-      env: flags.env
-    })
-    if (!instance.hash) throw new Error('invalid instance')
-    this.spinner.stop(instance.hash)
-    return instance
+    try {
+      const instance = await this.api.instance.create({
+        serviceHash,
+        env: flags.env
+      })
+      if (!instance.hash) throw new Error('invalid instance')
+      this.spinner.stop(instance.hash)
+      return instance
+    } catch (err) {
+      throw errorConversion(err)
+    }
   }
 }

src/utils/error.ts

@@ -0,0 +1,24 @@
+export class IsAlreadyExistsError extends Error {
+  static ID = 'ALREADY_EXISTS'
+  static regexp = new RegExp('\"(.*)\" already exists')
+  static match(err: Error) {
+    return IsAlreadyExistsError.regexp.test(err.message)
+  }
+
+  hash: string
+
+  constructor(error: Error) {
+    super(error.message)
+    const res = IsAlreadyExistsError.regexp.exec(error.message)
+    const hash = res && res.length >= 1 ? res[1] : ''
+    this.hash = hash
+    this.name = IsAlreadyExistsError.ID
+  }
+}
+
+export const errorConversion = (err: Error): Error => {
+  if (IsAlreadyExistsError.match(err)) {
+    return new IsAlreadyExistsError(err)
+  }
+  return err
+}