Cannot import JSON when isolatedModules is true

[brunolemos]

TypeScript Version: 3.2.0-dev.20181027

Search Terms: json isolatedModules, resolveJsonModule isolatedModules

Code

import test from './test.json'

tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "preserve"
  },
  "include": [
    "src"
  ]
}

Expected behavior:

Imports JSON without any error.

Actual behavior:

TS1208: Cannot compile namespaces when the '--isolatedModules' flag is provided.

Playground Link: Could not find a playground that supports editing tsconfig.json, adding a json file and that would show tsc output

Related Issues: #15230, #18232, https://stackoverflow.com/q/52103265/2228575