How can I completely hide an irrelevant directory of type declarations from TypeScript?

user_388951 0
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I'm trying to improve my tsc build times and editor responsiveness by reducing the number of source files that TypeScript pulls in. I'm seeing lots of .d.ts files in node_modules that are being pulled in via transitive dependencies, and I'd like a way to exclude them from consideration during compilation.

To make this more concrete: I'm using PgTyped to generate TypeScript type declarations for my SQL queries. To use it, I need to install two dependencies:

npm install @pgtyped/query @pgtyped/cli

The @pgtyped/query package depends on antlr4ts, which ships with many bundled .d.ts files of its own. These get pulled into my node_modules directory:

$ ls node_modules/antlr4ts/**/*.d.ts | wc -l
179

Some of these types do get pulled in via node_modules/@pgtyped/query/lib/index.d.ts. I can see this by using tsc --listFiles:

$ tsc --noEmit --listFiles | grep antlr4ts
/myrepo/ts/node_modules/antlr4ts/atn/ATNStateType.d.ts
/myrepo/ts/node_modules/antlr4ts/misc/Stubs.d.ts
/myrepo/ts/node_modules/antlr4ts/misc/IntegerList.d.ts
/myrepo/ts/node_modules/antlr4ts/misc/Interval.d.ts
...

So far as I can tell (famous last words!) these are all irrelevant to the public API of PgTyped. If I just replaced them with any, there would be no observable difference to my app and there would be ~100 fewer files that tsc would need to load.

I've tried a few techniques suggested on the TypeScript Wiki's Performance Page, namely including **/node_modules in my exclude:

{
  "compilerOptions": {
    "lib": [ "dom", "DOM.Iterable", "es2019" ],
    "strict": true /* Enable all strict type-checking options. */,
    "skipLibCheck": true,
    // ... many other settings ...
  },
  "exclude": [
    "./cypress",
    "**/node_modules",
    "**/.*/"
  ]
}

I've set skipLibCheck and also tried creating a declaration file to stub out antlr4ts:

// declarations/antlr4ts.d.ts
declare module 'antlr4ts';

This file shows up in the output of tsc --listFiles, but only after all 110 of the antlr4ts declarations files.

Is it possible to prevent TypeScript from seeing any of these .d.ts files? Ideally I'd like to have it give all of these antlr4ts modules an any type.

typescript
2 Answers

To improve your editor responsiveness, you can try adding watchOptions with excludeDirectories to your tsconfig file (doc). This way, you can tell your editor should not to search inside node_modules. From Typescript webpage:

TypeScript 3.8 introduces a new watchOptions field which allows users to tell the compiler/language service which watching strategies should be used to keep track of files and directories.

About the build time, typescript does not compile the files inside your node_modules, it only looks for type declaration files (d.ts). This should be quick (a few seconds) but it doesn't seem to be a solution to ignoring those files at the moment. One thing you can do to reduce build time is to use Typescript's incremental mode when compiling. This will save compiler info into your project and speed up the following compilations.

user_19746810

Try this in tsconfig:

"paths": {
    "antlr4ts" : ["NOT_EXISTS"] 
}

or perhaps point it to your declarations file

"paths": {
    "antlr4ts" : ["declarations/antlr4ts.d.ts"] 
}

Sidenote - I'm not sure if it will save a significant amount of build time, even if it works

user_105208390
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