fix: ignore package.json file to prevent invalid code-path (#727)

The error in #674 is caused by a change of the package.json file during the build, which triggers some code path that is valid in WatchCompilerHostOfConfigFile but not in WatchCompilerHostOfFilesAndCompilerOptions that this plugin uses (because of configOverwrite option). This commit ignores the package.json file in watcher as a work-around.

Closes: #674

Author: piotr-oles

src/watch/inclusive-node-watch-file-system.ts

@@ -12,6 +12,8 @@ import type { ForkTsCheckerWebpackPluginState } from '../plugin-state';
 import type { WatchFileSystem } from './watch-file-system';
 
 const BUILTIN_IGNORED_DIRS = ['node_modules', '.git', '.yarn', '.pnp'];
+// we ignore package.json file because of https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/issues/674
+const BUILTIN_IGNORED_FILES = ['package.json'];
 
 function createIsIgnored(
   ignored: string | RegExp | (string | RegExp)[] | undefined,
@@ -35,6 +37,9 @@ function createIsIgnored(
   ignoredFunctions.push((path: string) =>
     BUILTIN_IGNORED_DIRS.some((ignoredDir) => path.includes(`/${ignoredDir}/`))
   );
+  ignoredFunctions.push((path: string) =>
+    BUILTIN_IGNORED_FILES.some((ignoredFile) => path.endsWith(`/${ignoredFile}`))
+  );
 
   return function isIgnored(path: string) {
     return ignoredFunctions.some((ignoredFunction) => ignoredFunction(path));