Possible Regression: resolveJsonModule Projects must list all files or use an 'include' pattern.

TypeScript Version: 3.7.0-dev.20190912

Search Terms:

resolveJsonModule Projects must list all files or use an 'include' pattern

Code

tsconfig.json

{
  "extends": "../../tsconfig.base.json",
  "compilerOptions": {
    "outDir": "./dist",
    "rootDir": "./src",
    "strictNullChecks": true,
    "resolveJsonModule": true
  },
  "include": ["src/**/*.ts", "src/**/*.json"],
  "references": []
}

tsconfig.base.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es2017",
    "lib": ["es2017"],
    "composite": true,
    "esModuleInterop": true,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "sourceMap": true,
    "skipLibCheck": true
  }
}

Expected behavior:

When resolveJsonModule is turned on, and json files have been included in the includes array, I should be able to import json files with no trouble.

Actual behavior:

When I use the above tsconfig options, and include a json file, I get the following error:

Related Issues:

https://github.com/microsoft/TypeScript/issues/31181

[Jack-Works]

@razzeee https://github.com/elm-tooling/elm-language-server/blob/rank/tsconfig.json#L17 is not sufficient. You have to explicitly list json files to be included. Changing that to "include": ["src", "src/**/*.json"] fixes the issue.

Why do I need to do that even I have --resolveJsonModule on?

If a glob pattern doesn’t include a file extension, then only files with supported extensions are included (e.g. .ts, .tsx, and .d.ts by default, with .js and .jsx if allowJs is set to true).

In the document of includes. I think .json should be included too when resolveJsonModule is on.

[razzeee]

Thank you, that fixes compilation, after restarting VSCode