feat: hook.error()

index.js

@@ -2,8 +2,10 @@ module.exports = Hook
 
 var register = require('./lib/register')
 var before = require('./lib/before')
+var error = require('./lib/error')
 var after = require('./lib/after')
 var removeBefore = require('./lib/remove-before')
+var removeError = require('./lib/remove-error')
 var removeAfter = require('./lib/remove-after')
 
 function Hook () {
@@ -15,10 +17,12 @@ function Hook () {
  hook.api = {}
 
  hook.api.before = hook.before = before.bind(null, state)
+ hook.api.error = hook.error = error.bind(null, state)
  hook.api.after = hook.after = after.bind(null, state)
 
  hook.api.remove = hook.remove = {
  before: removeBefore.bind(null, state),
+ error: removeError.bind(null, state),
  after: removeAfter.bind(null, state)
  }
 

lib/after.js

@@ -1,13 +1,14 @@
-module.exports = after
+module.exports = afterHook
 
-function after (state, name, afterHook) {
+function afterHook (state, name, afterHook) {
  if (state.registry[name]) {
  state.registry[name].after.push(afterHook)
  return
  }
 
  state.registry[name] = {
  before: [],
+ error: [],
  after: [afterHook]
  }
 }

lib/before.js

@@ -1,13 +1,14 @@
-module.exports = before
+module.exports = beforeHook
 
-function before (state, name, beforeHook) {
+function beforeHook (state, name, beforeHook) {
  if (state.registry[name]) {
  state.registry[name].before.unshift(beforeHook)
  return
  }
 
  state.registry[name] = {
  before: [beforeHook],
+ error: [],
  after: []
  }
 }

lib/error.js

@@ -0,0 +1,14 @@
+module.exports = errorHook
+
+function errorHook (state, name, errorHook) {
+ if (state.registry[name]) {
+ state.registry[name].error.unshift(errorHook)
+ return
+ }
+
+ state.registry[name] = {
+ before: [],
+ error: [errorHook],
+ after: []
+ }
+}

lib/register.js

@@ -26,6 +26,7 @@ function register (state, name, options, method) {
  }
 
  var beforeHooks = hooks.before
+ var errorHooks = hooks.error
  var afterHooks = hooks.after
 
  return Promise.all(beforeHooks.map(invokeBeforeHook.bind(null, options)))
@@ -34,6 +35,20 @@ function register (state, name, options, method) {
  return method(options)
  })
 
+ .catch(function (error) {
+ return Promise.all(errorHooks.map(invokeErrorHook.bind(null, error, options)))
+
+ .then(function (results) {
+ var nonErrorResults = results.filter(isntError)
+
+ if (nonErrorResults.length) {
+ return nonErrorResults[0]
+ }
+
+ throw error
+ })
+ })
+
  .then(function (result) {
  return Promise.all(afterHooks.map(invokeAfterHook.bind(null, result, options)))
 
@@ -59,10 +74,24 @@ function invokeBeforeHook (options, method) {
  }
 }
 
+function invokeErrorHook (result, options, errorHook) {
+ try {
+ return Promise.resolve(errorHook(result, options))
+
+ .catch(function (error) { return error })
+ } catch (error) {
+ return Promise.resolve(error)
+ }
+}
+
 function invokeAfterHook (result, options, method) {
  try {
  return method(result, options)
  } catch (error) {
  return Promise.reject(error)
  }
 }
+
+function isntError (result) {
+ return !(result instanceof Error)
+}

lib/remove-after.js

@@ -1,6 +1,6 @@
-module.exports = removeAfter
+module.exports = removeAfterHook
 
-function removeAfter (state, name, method) {
+function removeAfterHook (state, name, method) {
  if (!state.registry[name]) {
  return
  }

lib/remove-before.js

@@ -1,6 +1,6 @@
-module.exports = removeBefore
+module.exports = removeBeforeHook
 
-function removeBefore (state, name, method) {
+function removeBeforeHook (state, name, method) {
  if (!state.registry[name]) {
  return
  }

lib/remove-error.js

@@ -0,0 +1,15 @@
+module.exports = removeErrorHook
+
+function removeErrorHook (state, name, method) {
+ if (!state.registry[name]) {
+ return
+ }
+
+ var index = state.registry[name].error.indexOf(method)
+
+ if (index === -1) {
+ return
+ }
+
+ state.registry[name].error.splice(index, 1)
+}