Should not compile everything

[tkrotoff]

ts-loader compiles a lot more files than it should. ts-loader should only compile files known to webpack (e.g webpack.config.js entry + its children) (and/or files specified in tsconfig.json (*))

Setup:

• webpack.config.js with an entry ./index.ts + ts-loader
• a file fail.ts:

// Fail to compile with TypeScript with "'const' declarations must be initialized"
// + is not imported by index.ts
const fail;

Results:

• Case 1 no tsconfig.json

ERROR in error TS18002: The 'files' list in config file 'tsconfig.json' is empty.

ERROR in ./index.ts
Module build failed: error while parsing tsconfig.json

=> KO, ts-loader should work without a file tsconfig.json (or at least the error message is incorrect and should be "error: no tsconfig.json")

• Case 2 empty tsconfig.json without files and include

ERROR in /Users/tanguy/flex-wrap-layout/src/fail.ts
(1,7): error TS1155: 'const' declarations must be initialized.

=> KO, this is the main case, fail.ts is not specified anywhere (tsconfig.json and webpack.config.js) so ts-loader should not compile it.

• Case 3 tsconfig.json with files (*)
  • Case 3.1 files with index.ts ("files": ["index.ts"]): no error => this is OK
  • Case 3.2 files with index.ts and fail.ts ("files": ["index.ts", "fail.ts"]): fail.ts error => this is OK

Comparison with rollup-plugin-typescript2:

• Case 1: [!] Error: couldn't find 'tsconfig.json'
• Case 2: does not compile fail.ts => OK
• Case 3.1: does not compile fail.ts => OK
• Case 3.2: does not compile fail.ts
• Case 3.2bis "include": ["*.ts"]: does not compile fail.ts

(*) I even believe that ts-loader should totally ignore tsconfig.json files (but use compilerOptions of course) and only rely on webpack.config.js entry (and its imported children). This is what rollup-plugin-typescript2 does.

[johnnyreilly]

Closing as duplicate of #267