Add more features

Author: ehmicky

README.md

@@ -19,46 +19,60 @@ const onProcessError = require('on-process-error')
 const undoSetup = onProcessError.setup()
 ```
 
-When any process errors occur, it will be logged using `console.error()`:
+When any process errors occur, it will be logged using `console.error()`.
+The message will include detailed information about the error.
 
-- the message will include detailed information about the error
-- for `warning`, `console.warn()` will be used instead.
-- for `uncaughtException`, [`process.exit(1)` will be called after
-  `console.error()`](https://nodejs.org/api/process.html#process_warning_using_uncaughtexception_correctly).
+For `warning`, `console.warn()` will be used instead.
 
 You can undo everything by firing the function returned by
 `onProcessError.setup()` (called `undoSetup` in the example above).
 
+# Example output
+
+TO BE DONE
+
 # Custom handling
 
-You can override the default behavior by passing a custom function instead.
+You can override the default behavior by passing a custom function to the
+`handle` option.
 
 <!-- eslint-disable no-empty-function, no-unused-vars, node/no-missing-require,
-import/no-unresolved, unicorn/filename-case, strict -->
+import/no-unresolved, unicorn/filename-case, strict, no-undef -->
 
 ```js
-const onProcessError = require('on-process-error')
-
-const undoSetup = onProcessError.setup(
-  ({ eventName, promiseState, promiseValue, error, message }) => {},
-)
+onProcessError.setup({
+  handle({ eventName, promiseState, promiseValue, error, message }) {},
+})
 ```
 
+This can be useful if you want to use your own logger instead of the console.
+
 The function's argument is an object with the following properties:
 
 - `eventName` `{string}`: can be `uncaughtException`, `unhandledRejection`,
   `rejectionHandled`, `multipleResolves` or `warning`
+- `error` `{any}` is either:
+  - value thrown by `uncaughtException`. Usually an `Error` instance, but not
+    always.
+  - `Error` instance emitted by `warning`.
+    [`error.name`, `error.code` and `error.detail`](https://nodejs.org/api/process.html#process_event_warning)
+    might be defined.
 - `promiseState` `{string}`: whether promise was `resolved` or `rejected`.
   For `unhandledRejection`, `rejectionHandled` and `multipleResolves`.
 - `promiseValue` `{any}`: value resolved/rejected by the promise.
   For `unhandledRejection`, `rejectionHandled` and `multipleResolves`.
-- `error` `{error}`:
-  - can be:
-    - thrown by `uncaughtException`
-    - emitted by `warning`. [`error.name`, `error.code` and `error.detail`](https://nodejs.org/api/process.html#process_event_warning)
-      might be defined.
-    - rejected by `unhandledRejection`, `rejectionHandled` or
-      `multipleResolves`'s promise (if the promise was rejected).
-  - if the error is not an `Error` instance (e.g. if it is a string), it will
-    be normalized to one using `new Error()`.
 - `message` `{string}`: detailed message summing up all of the above.
+
+# Exiting on uncaught exceptions
+
+By default, `uncaughtException` will fire `process.exit(1)`. This is the recommended behavior according to the
+[Node.js documentation](https://nodejs.org/api/process.html#process_warning_using_uncaughtexception_correctly).
+
+You can disable this by setting the `exitOnExceptions` option to `false`:
+
+<!-- eslint-disable no-empty-function, no-unused-vars, node/no-missing-require,
+import/no-unresolved, unicorn/filename-case, strict, no-undef -->
+
+```js
+onProcessError.setup({ exitOnExceptions: false })
+```

package-lock.json

@@ -36,7 +36,9 @@
   },
   "author": "autoserver founder <[email protected]> (http://autoserver.io)",
   "directories": {},
-  "dependencies": {},
+  "dependencies": {
+    "chalk": "^2.4.1"
+  },
   "devDependencies": {
     "eslint": "^5.7.0",
     "eslint-config-prettier": "^3.1.0",

package.json

@@ -1,17 +1,10 @@
 'use strict'
 
-const { exit } = require('process')
-
 // Default event handler
 const defaultHandler = function({ eventName, message }) {
   const level = eventName === 'warning' ? 'warn' : 'error'
   // eslint-disable-next-line no-restricted-globals, no-console
   console[level](message)
-
-  // See https://nodejs.org/api/process.html#process_warning_using_uncaughtexception_correctly
-  if (eventName === 'uncaughtException') {
-    exit(1)
-  }
 }
 
 module.exports = {

src/default.js

@@ -14,7 +14,7 @@ const warning = function(context, error) {
 }
 
 const unhandledRejection = function(context, promiseValue, promise) {
-  handleEvent({ ...context, promise })
+  handleEvent({ ...context, promise, promiseValue })
 }
 
 const rejectionHandled = function(context, promise) {

src/error.js

@@ -1,35 +1,50 @@
 'use strict'
 
-const { getError } = require('./error')
+const { exit } = require('process')
+
+const { parsePromise } = require('./promise')
 const { getMessage } = require('./message')
 
 // Generic event handler for all events.
-const handleEvent = async function({ handlerFunc, eventName, error, promise }) {
-  const { promiseState, promiseValue } = await parsePromise({ promise })
-  const errorA = getError({ error, promiseValue })
+const handleEvent = async function({
+  opts: { handlerFunc, exitOnExceptions },
+  eventName,
+  error,
+  promise,
+  promiseValue,
+}) {
+  const { promiseState, promiseValue: promiseValueA } = await parsePromise({
+    eventName,
+    promise,
+    promiseValue,
+  })
   const message = getMessage({
     eventName,
     promiseState,
-    promiseValue,
-    error: errorA,
+    promiseValue: promiseValueA,
+    error,
   })
 
-  handlerFunc({ eventName, promiseState, promiseValue, error: errorA, message })
+  handlerFunc({
+    eventName,
+    promiseState,
+    promiseValue: promiseValueA,
+    error,
+    message,
+  })
+
+  exitProcess({ eventName, exitOnExceptions })
 }
 
-// Retrieve promise's resolved/rejected state and value.
-const parsePromise = async function({ promise }) {
-  // `uncaughtException` and `warning` events do not have `promise`.
-  if (promise === undefined) {
-    return {}
+// Exit process on `uncaughtException`
+// See https://nodejs.org/api/process.html#process_warning_using_uncaughtexception_correctly
+// Can be disabled with `opts.exitOnExceptions: false`
+const exitProcess = function({ eventName, exitOnExceptions }) {
+  if (eventName !== 'uncaughtException' || !exitOnExceptions) {
+    return
   }
 
-  try {
-    const promiseValue = await promise
-    return { promiseState: 'resolved', promiseValue }
-  } catch (error) {
-    return { promiseState: 'rejected', promiseValue: error }
-  }
+  exit(1)
 }
 
 module.exports = {

src/events.js

@@ -6,20 +6,27 @@ const { defaultHandler } = require('./default')
 const EVENTS = require('./events')
 
 // Add event handling for all process-related errors
-const setup = function(handlerFunc = defaultHandler) {
-  const listeners = addListeners({ handlerFunc })
+const setup = function(opts) {
+  const optsA = { ...DEFAULT_OPTS, ...opts }
+
+  const listeners = addListeners({ opts: optsA })
   const removeAll = removeListeners.bind(null, listeners)
   return removeAll
 }
 
-const addListeners = function({ handlerFunc }) {
-  return Object.entries(EVENTS).map((eventName, eventFunc) =>
-    addListener({ handlerFunc, eventName, eventFunc }),
+const DEFAULT_OPTS = {
+  handlerFunc: defaultHandler,
+  exitOnExceptions: true,
+}
+
+const addListeners = function({ opts }) {
+  return Object.entries(EVENTS).map(([eventName, eventFunc]) =>
+    addListener({ opts, eventName, eventFunc }),
   )
 }
 
-const addListener = function({ handlerFunc, eventName, eventFunc }) {
-  const eventListener = eventFunc.bind(null, { handlerFunc, eventName })
+const addListener = function({ opts, eventName, eventFunc }) {
+  const eventListener = eventFunc.bind(null, { opts, eventName })
   process.on(eventName, eventListener)
 
   return { eventListener, eventName }