typescript outDir setting in tsconfig.json not working

Question

I can't seem to get the outDir flag working when used in package.json. Directory structure is pretty simple: tsconfig.json at the root level, together with a src/ directory and a single index.ts file plus other directories representing other modules.

When running the tsc command on the index file, it creates a new one beside it instead of in the build directory. What am I doing wrong?

My tsconfig:

{
  "compilerOptions": {
    "outDir": "build"
  }
}

My npm build script:

"build": "tsc src/index.ts"

I'm calling the script from the root dir of the project. Interestingly, running the same script with an --outDir flag works just fine.

Answer 1

When you pass in files for compilation with tsc src/index.ts, your tsconfig.json is ignored.

From the documentation:

When input files are specified on the command line, tsconfig.json files are ignored.

Your npm build script should just be tsc without passing any files.