TypeScript: Duplicate identifier 'IteratorResult'

Question

I\'m trying to compile via tsc--which I\'ve installed globally--and I\'m getting an error:

~/AppData/R         


        

Answer 1

I suspect it is because your include section:

"include": [
    "app/**/*.ts",
    "app/**/*.tsx",
    "test/**/*.ts",
    "test/**/*.tsx",
    "node_modules/@types/**/*.d.ts",
    "./types/**/*.d.ts"
  ]

You usually don't need to explicitly include *.d.ts files. And probably never declaration files from other libraries (or node types).

tsconfig's "exclude" section excludes everything under "node_modules" by default (among other things). When you add "node_modules/@types/**/*.d.ts" you override that exclude and tsc tries to include them, but those types are already declared.

Check Typescript docs on tsconfig.json, it explains the "typeRoots", "files" and "include"/"exclude" config options in detail.