Hot Module Replacement (HMR) is a feature in certain development tools and frameworks that allows developers to update modules in an application without requiring a full page refresh. This helps in speeding up the development process and making it more efficient. HMR is commonly used in the context of front-end development, especially with JavaScript frameworks like React, Vue.js, and Angular.
- Module Replacement: When a file is modified during development, instead of refreshing the entire application, only the modified module is replaced.
- Preserving State: HMR attempts to preserve the state of the application, meaning that if you have some data in your application’s state, it will try to keep that data intact even after a module update.
- Fast Feedback Loop: HMR provides a faster feedback loop for developers, as they can see the changes they make in real-time without having to manually refresh the browser.
- No Loss of State: Since only the modified modules are replaced, developers don’t lose the current state of the application. This can be particularly useful when working on complex applications.
HMR is not exclusive to front-end development; it can also be used in other environments like server-side development. The exact implementation details may vary depending on the development tool or framework being used. Popular tools like Webpack, Parcel, and others provide built-in support for HMR, making it relatively easy for developers to integrate into their projects.