TS5055 error while import a non relative json module with resolveJsonModule option

[grayflow]

TypeScript Version: 3.0.0-dev.20180605

Search Terms: TS5055 resolveJsonModule

Code

tsjson> find .
.
./main.ts
./json
./json/myjson.json
./tsconfig.json
./src
./src/test.ts

tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "module": "es2015",
    "moduleResolution": "node",
    "baseUrl": "./",

    "resolveJsonModule": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,


    "strict": true,
    "noEmitOnError": true
  },
  "include": [
    "main.ts",
    "src",
    "json"
  ],
  "exclude": [
    "node_modules"
  ]
}

main.ts:

import "test";

src/test.ts:

import myjson from "json/myjson.json";

console.log('hello world!', myjson.message);
export {}

json/myjson.json:

{
    "message": "to be continue..."
}

Expected behavior:
compile successful

Actual behavior:
tsjson> tsc
error TS5055: Cannot write file '*************/tsjson/json/myjson.json' because it would overwrite input file.

Playground Link:

Related Issues:

[mhegazy]

the compiler when resolving a .json file will read it and write it again. so you really want to have --outDir option set to avoid the compiler overwriting you input file.

[ezolenko]

In this case the error pops out when rollup plugin calls ts.parseConfigFileTextToJson() -- not when typescript is trying to overwrite the file -- in fact typescript won't be doing any file writes at all, all transpiled code is getting fed to rollup.

I will do a workaround by providing a fake outDir value, but the check probably doesn't belong in parseConfigFileTextToJson.

[jpike88]

@mhegazy If there is no outDir specified, why should the .json file be duplicated? It's a static resource... is there a way to do this without needing outDir?

[jpike88]

#24743

[grayflow]

@mhegazy, still not feel right: if import a native js module, it won't issue TS5055 error

[grayflow]

maybe add an compile option --allowJson(and default to false) like --allowJs for js file?

[mhegazy]

still not feel right: if import a native js module, it won't issue TS5055 error

cause the compiler does not overwrite .d.ts files. so no issue here.

maybe add an compile option --allowJson(and default to false) like --allowJs for js file?

if you use --allowJs you will get the same error. once the compiler tries to write a file in the same locations a source file an error is issued. This guarantees there are no user data loss caused by the compiler overwriting an existing file.

[grayflow]

yes , import js module and set --allowJs to true would cause TS5055 too. if we know the imported js file do not need to be transformed(compiled), we would set allowJs to false, and i think that is the point to provide allowJs option. json file/module would never need to be transformed, so why not just make them "no emit" by default (and we don't lose anything)?

[mhegazy]

if we know the imported js file do not need to be transformed(compiled)

well we do not rely know that.

[ezolenko]

And this is why ts.parseConfigFileTextToJson() might be a wrong place for the check :)

[jpike88]

@mhegazy

the compiler when resolving a .json file will read it and write it again

If the outDir is different, that makes sense. But if not, then why try to overwrite it? .json files are closer to being treated like static assets than javascript, so there isn't a 'build artefact' equivalent here.

[impacmp]

this issue should be solved since it makes sence to use "./" as outDir in some cases