Investigate implicit excludes

Today, TypeScript will implicitly set exclude to ./node_modules and something like .*/**/* to avoid dot files.

Unfortunately, there are two problems I believe I've found from chatting with users.

First, users often end up setting exclude which overrides the defaults. This often means that users accidentally over-include files, and that can cause performance issues.

Next, these defaults don't work out well enough, and end up going a bit off the rails in certain scenarios. For example, consider the following .js monorepo.

packages
+- package-aaa
|  +- node_modules    <- the cute tiny 10MB node_modules
|
+- jsconfig.json
+- node_modules        <- the slightly bigger 10GB node_modules
                         shared by each package

Notice that jsconfig.json or not, one of these node_modules is going to be crawled through unless exclude is set appropriately. And regardless of whether exclude is implicitly or explicitly on, it's usually wrong. In this case, it should (probably) be **/node_modules/**/*. For example, check out https://github.com/IBM/report-toolkit/pull/44/files

What I'm suggesting is to harden exclude to always contain the following paths regardless of whether exclude is set.

• **/node_modules/**/*
• .*/**

To disable this, users will have to turn off a setting like enableImplicitExcludePatterns.

まず、issue に記載された .js モノレポのレイアウトを再現し、jsconfig.json がある場合とない場合、および明示的な exclude を指定した場合の動作を比較します。現在の暗黙的な exclude の動作が、node_modules の両方の場所とドットファイルをどのように扱うかを調査します。提案されたパターンを適用または無効化するための合意されたアプローチを確立できれば完了です。