How to Optimize TypeScript Builds with Incremental Compilation

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I’m a book editor working on a series of novels. Every time the author submits a new draft, I don’t want to reread the entire series to find the changes; instead, I want to focus just on the new chapters or any revised sections. This way, I can efficiently keep the entire series polished without wasting time on parts that haven’t changed.

In the world of TypeScript, this is similar to how I configure the TypeScript compiler for incremental builds. Think of each chapter of the book as a file in my TypeScript project. When I enable incremental builds, it’s like setting up a system where I only review the chapters that have been updated or are new. This is done by creating a sort of “memory” of past edits, which in TypeScript terms is a cache of previous compilations.

To set this up, I dive into my tsconfig.json file—this is like my editor’s notebook where I jot down important guidelines for my editing process. Here, I add "incremental": true, which is equivalent to writing a note to myself: “Remember changes between drafts.” I also specify a "tsBuildInfoFile" to store this memory, ensuring I know exactly where to look when I pick up the next draft.

Every time the author gives me a new version, my editing process swiftly skips over unchanged chapters, allowing me to focus my energy and attention on only what’s new or modified. This efficiency means I can keep up with the fast pace of submissions without getting overwhelmed. So, just like my editing system helps me manage novels effectively, incremental builds keep my TypeScript projects running smoothly and efficiently.

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In the world of TypeScript, our tsconfig.json file is like my editor’s notebook. By adding "incremental": true, I’m telling the TypeScript compiler to remember past compilations, similar to how I remember past edits in the book series. Here’s how I set it up:

{
  "compilerOptions": {
    "incremental": true,
    "tsBuildInfoFile": "./.tsbuildinfo",
    "outDir": "./dist"
  },
  "include": ["src/**/*"]
}

In this configuration:

• "incremental": true is like making a note to remember changes between drafts, so I don’t have to start fresh each time.
• "tsBuildInfoFile": "./.tsbuildinfo" specifies where this memory or cache is stored, just like keeping an organized file of past edits.
• "outDir": "./dist" tells the compiler where to put the compiled JavaScript files, akin to deciding where the final edited chapters will be stored.

When I run the TypeScript compiler using tsc, it now uses this setup to only recompile files that have changed or have dependencies that changed. This is like focusing only on new or revised chapters, rather than rereading the whole series. This process can significantly speed up build times, especially in large projects.

Key Takeaways

1. Incremental Builds: By enabling incremental builds in TypeScript, we can improve the efficiency of our build process by reusing information from previous compilations.
2. Configuration Matters: Setting "incremental": true in tsconfig.json and specifying a "tsBuildInfoFile" are essential steps to enable this feature.
3. Efficiency in Large Projects: Just as I save time by only editing new or changed chapters, incremental builds allow developers to focus on modified files, speeding up the development process.
4. Practical Use: This setup is particularly useful for large projects where recompiling everything from scratch would be time-consuming.