TS 5.6 `files` missing from `--showConfig` (with absolute / ``${configDir}`` `include` paths)

🔎 Search Terms

"--showConfig", "include", "configDir", "files", "extends", "absolute"

🕗 Version & Regression Information

• Tested versions:
  • 3.2.1 (--showConfig was introduced here)
  • 3.2.4
  • 5.5.2 (${configDir} was introduced here)
  • latest => 5.6.3
  • next =>5.7.0-dev.20241011
• This is the behaviour in every version I tried, and I reviewed the FAQ for entries about "configDir", "showConfig", "absolute".
• I was unable to test this on prior versions because --showConfig cli flag was introduced in TS 3.2 and configDir template variable was introduced in TS 5.5.

⏯ Playground Link

No response

💻 Code

// tsconfig-rel.json
{
    //...
    "include": ["src/**/*"]
}

// tsconfig-abs.json
{
    //...
    "include": ["/path/to/src/**/*"]
}

// tsconfig-cnf.json
{
    //...
    "include": ["${configDir}/src/**/*"]
}

// src/index.ts
console.log("dummy");

🙁 Actual behavior

❌ Printing config yields different results.

npx tsc --project tsconfig-rel.json --showConfig
npx tsc --project tsconfig-abs.json --showConfig
npx tsc --project tsconfig-cnf.json --showConfig

• For absolute include paths the files property is missing.
• ${configDir} is resolved to and behaves / fails the same as absolute paths.

  {
      "compilerOptions": {...},
-     "files": [
-         "./src/index.ts"
-     ],
      "include": [
-         "src/**/*"
+         "/path/to/src/**/*"
      ],
      "exclude": [...]
  }

✅ Listing files yields the same output.

npx tsc --project tsconfig-rel.json --listFiles --noEmit
npx tsc --project tsconfig-abs.json --listFiles --noEmit
npx tsc --project tsconfig-cnf.json --listFiles --noEmit

List of files printed to stdout, containing

• /path/to/src/index.ts
• /path/to/node_modules/**/*.d.ts entries from npm dependency type declarations.
• /path/to/node_modules/typescript/lib/lib.decorators.d.ts (only in TS 5 of course)
• /path/to/node_modules/typescript/lib/lib.decorators.legacy.d.ts (only in TS 5 of course)

✅ Building yields the same index.js file content for all configs.

npx tsc --project tsconfig-rel.json
npx tsc --project tsconfig-abs.json
npx tsc --project tsconfig-cnf.json

🙂 Expected behavior

--showConfig should show the same files for configs that build the same files and show the same listing for --listFiles.

Additional information about the issue

includeRe in matchesSpecs seems to be calculated differently for absolute / relative paths, resulting in all files being filtered out in convertToTSConfig.

I can't tell though which behaviour is actually expected. (keep files or filter files out?)

src/compiler/commandLineParser.ts の matchesSpecs と convertToTSConfig から始めます。ここでは、issue が絶対パスと相対パスの include パスで処理が異なることを報告しています。3 つの tsconfig ケースを tsc --showConfig で再現し、次に期待されるファイル出力を特定して、それが --listFiles とビルドによって選択されたファイルと一致することを確認します。