Redux Observable Backend - Core

What is this library?

Helper functions for Redux-Observable-Backend packages. These functions can be used in any project. This package also provides uncaught exception logging.

Installation

This package requires rxjs as a peerDependency.

npm

npm i rxjs @redux-observable-backend/core

yarn

yarn add rxjs @redux-observable-backend/core

API Overview

Functional Helpers

• tryCatchFinally

Import Mechanisms

• removeFilePathFromRequireCache
• safeImport

Node.js Framework Helpers

• createDeprecationFunction
• deprecateArgument
• logUncaughtExceptions

API Docs

createDeprecationFunction

When developing locally, removes the given filePath from Node.js's require cache.

This is especially useful when server-side rendering because you can reload the static HTML file built by Webpack (or similar) when loading it in Express (or similar).

Example

Deprecated function

createDeprecationFunction({
  adapter: mapToState,
  deprecatedMethodName: 'mapToState',
})

Replaced function

createDeprecationFunction({
  adapter: state => superMapToState({ state }),
  deprecatedMethodName: 'mapToState',
  replacementMethodName: 'superMapToState'
})

Args (Object)

This function returns a function that takes the same parameters as the function you've deprecated.

adapter (Function)

This is a function that converts the arguments of the deprecated function to the replacement function. This provides an automatic way forward and informs consumers with console logs when these deprecations occur. This way, they can convert to the newer function later, but current operations will still work as-intended.

deprecatedMethodName (String)

Function name being deprecated.

replacementMethodName (String)

Function name to use instead of the deprecated version. If the function has no replacement, leave this field blank.

---

deprecateArgument

This function logs a message for any use of an argument when calling a function and provides an alternative argument to use instead. It's designed to be used by adding it to the top of your function before any business logic.

The intended purpose of deprecateArgument is when you have a function arg that changed or when it

If you need to convert from one argument to another, deprecateArgument doesn't handle this. That should be handled in your own code as it's specific to your situation.

Example

Deprecated argument

deprecateArgument({
  deprecatedArgumentName: 'additionalDefaultConfigurationSet',
  methodName: 'createConfigurationSet',
})

Renamed argument

deprecateArgument({
  deprecatedArgumentName: 'disabled',
  methodName: 'Button',
  replacementArgumentName: 'isDisabled',
})

Denote a type change

deprecateArgument({
  deprecatedArgumentName: 'firstArg (string)',
  methodName: 'generateLink',
  replacementArgumentName: firstArg ({ href: '' (string), isActive: true (boolean) }),
})

Args (Object)

deprecatedArgumentName (String)

A string representing the deprecated argument name.

methodName (String)

A string representing the name of the function called with this deprecation.

replacementArgumentName (String)

A string representing the replacement argument name if any.

---

logUncaughtExceptions

Sometimes, Node.js applications can crash without error. To alleviate this problem, this logger catches uncaught exceptions and logs them before killing the application. This way, you're aware when an uncaught error's occurred.

Example

logUncaughtExceptions()

Args

N/A

---

removeFilePathFromRequireCache

When developing locally, removes the given filePath from Node.js's require cache.

This is especially useful when server-side rendering because you can reload the static HTML file built by Webpack (or similar) when loading it in Express (or similar).

Example

removeFilePathFromRequireCache(
  './build/serverSideRender.js'
)

Args

filePath (String)

Path to the file for require. This path can be a module alias.

---

safeImport

Safely imports files with require syntax by allowing a defaultValue if the file doesn't exist or errors on load.

Example

safeImport({
  defaultValue: [],
  filePath: './cache.json',
})

Args (Object)

defaultValue (any)

Returned when file doesn't exist.

filePath (String)

Path to the file for require. This path can be a module alias.

---

tryCatchFinally

A functional method for doing a try-catch-finally. The catch exception is also logged.

Example

tryCatchFinally({
  defaultValue: [],
  finallyCallback = Function.prototype,
  tryCallback = Function.prototype,
})

Args (Object)

defaultValue (any)

defaultValue is returned when exception caught.

finallyCallback (Function)

Called when finally occurs.

tryCallback (Function)

Called when try occurs.