refactor: standard errors and remove first/last utils

Author: Alan Shaw

src/core/components-ipfsx/add/index.js

@@ -4,10 +4,9 @@ const importer = require('ipfs-unixfs-importer')
 const normaliseAddInput = require('ipfs-utils/src/files/normalise-input')
 const { parseChunkerString } = require('./utils')
 const pipe = require('it-pipe')
-const { withFirstAndLast } = require('../../utils')
 
 module.exports = ({ ipld, dag, gcLock, preload, pin, constructorOptions }) => {
-  return withFirstAndLast(async function * add (source, options) {
+  return async function * add (source, options) {
     options = options || {}
 
     const opts = {
@@ -53,7 +52,7 @@ module.exports = ({ ipld, dag, gcLock, preload, pin, constructorOptions }) => {
     } finally {
       releaseLock()
     }
-  })
+  }
 }
 
 function transformFile (dag, opts) {

src/core/components-ipfsx/init.js

@@ -15,9 +15,9 @@ const UnixFs = require('ipfs-unixfs')
 const multicodec = require('multicodec')
 const multiaddr = require('multiaddr')
 const {
-  ERR_ALREADY_INITIALIZING,
-  ERR_ALREADY_INITIALIZED,
-  ERR_NOT_STARTED
+  AlreadyInitializingError,
+  AlreadyInitializedError,
+  NotStartedError
 } = require('../../errors')
 const BlockService = require('ipfs-block-service')
 const Ipld = require('ipld')
@@ -35,7 +35,7 @@ module.exports = ({
   print,
   constructorOptions
 }) => async function init (options) {
-  const { cancel } = apiManager.update({ init: ERR_ALREADY_INITIALIZING })
+  const { cancel } = apiManager.update({ init: () => { throw new AlreadyInitializingError() } })
 
   try {
     options = mergeOptions({}, options, constructorOptions.init)
@@ -137,7 +137,7 @@ module.exports = ({
       repo
     })
 
-    apiManager.update(api, ERR_NOT_STARTED)
+    apiManager.update(api, () => { throw new NotStartedError() })
   } catch (err) {
     cancel()
     throw err
@@ -294,7 +294,7 @@ function createApi ({
 
   const api = {
     add,
-    init: ERR_ALREADY_INITIALIZED,
+    init: () => { throw new AlreadyInitializedError() },
     start
   }
 

src/core/components-ipfsx/stop.js

@@ -2,7 +2,7 @@
 
 const defer = require('p-defer')
 const Components = require('.')
-const { ERR_NOT_STARTED, ERR_ALREADY_INITIALIZED } = require('../../errors')
+const { NotStartedError, AlreadyInitializedError } = require('../../errors')
 
 module.exports = ({
   apiManager,
@@ -51,7 +51,7 @@ module.exports = ({
       repo
     })
 
-    apiManager.update(api, ERR_NOT_STARTED)
+    apiManager.update(api, () => { throw new NotStartedError() })
   } catch (err) {
     cancel()
     stopPromise.reject(err)
@@ -98,7 +98,7 @@ function createApi ({
 
   const api = {
     add,
-    init: ERR_ALREADY_INITIALIZED,
+    init: () => { throw new AlreadyInitializedError() },
     start,
     stop: () => apiManager.api
   }

src/core/errors.js

@@ -1,19 +1,43 @@
-const errCode = require('err-code')
-
-exports.ERR_NOT_INITIALIZED = () => {
-  throw errCode(new Error('not initialized'), 'ERR_NOT_INITIALIZED')
+class NotInitializedError extends Error {
+  constructor (message = 'not initialized') {
+    super(message)
+    this.name = 'NotInitializedError'
+    this.code = NotInitializedError.code
+  }
 }
 
-exports.ERR_ALREADY_INITIALIZING = () => {
-  const msg = 'cannot initialize an initializing node'
-  throw errCode(new Error(msg), 'ERR_ALREADY_INITIALIZING')
+NotInitializedError.code = 'ERR_NOT_INITIALIZED'
+exports.NotInitializedError = NotInitializedError
+
+class AlreadyInitializingError extends Error {
+  constructor (message = 'cannot initialize an initializing node') {
+    super(message)
+    this.name = 'AlreadyInitializingError'
+    this.code = AlreadyInitializedError.code
+  }
 }
 
-exports.ERR_ALREADY_INITIALIZED = () => {
-  const msg = 'cannot re-initialize an initialized node'
-  throw errCode(new Error(msg), 'ERR_ALREADY_INITIALIZED')
+AlreadyInitializingError.code = 'ERR_ALREADY_INITIALIZING'
+exports.AlreadyInitializingError = AlreadyInitializingError
+
+class AlreadyInitializedError extends Error {
+  constructor (message = 'cannot re-initialize an initialized node') {
+    super(message)
+    this.name = 'AlreadyInitializedError'
+    this.code = AlreadyInitializedError.code
+  }
 }
 
-exports.ERR_NOT_STARTED = () => {
-  throw errCode(new Error('not started'), 'ERR_NOT_STARTED')
+AlreadyInitializedError.code = 'ERR_ALREADY_INITIALIZED'
+exports.AlreadyInitializedError = AlreadyInitializedError
+
+class NotStartedError extends Error {
+  constructor (message = 'not started') {
+    super(message)
+    this.name = 'NotStartedError'
+    this.code = NotStartedError.code
+  }
 }
+
+NotStartedError.code = 'ERR_NOT_STARTED'
+exports.NotStartedError = NotStartedError

src/core/utils.js

@@ -127,25 +127,3 @@ const resolvePath = async function (objectAPI, ipfsPaths) {
 exports.normalizePath = normalizePath
 exports.parseIpfsPath = parseIpfsPath
 exports.resolvePath = resolvePath
-
-exports.withFirstAndLast = fn => {
-  return (...args) => {
-    const it = fn(...args)
-    return {
-      [Symbol.asyncIterator] () {
-        return it[Symbol.asyncIterator]()
-      },
-      async first () {
-        const { value } = await it.next()
-        return value
-      },
-      async last () {
-        let last
-        for await (const value of it) {
-          last = value
-        }
-        return last
-      }
-    }
-  }
-}