Error `TS5052` when `declarationDir` is set, but `declaration: false` override

What happens and why it is wrong

Typescript compile option doesn’t allow set declaration: false and declarationDir at same time.

options error TS5052 Option 'declarationDir' cannot be specified without specifying option 'declaration'.

But according to https://github.com/Microsoft/TypeScript/issues/14184, setting with declarationDir: null and declaration: false is able to cancel emitting type files.

Unfortunately, after setting override declarationDir: null, declaration: false and useTsconfigDeclarationDir:false, in lvl 3 verbosity, terminal reports that declarationDir in parsed tsconfig is current project path. The expected declarationDir should be null.

Environment

Versions

• typescript: 2.6.2
• rollup: 0.55.1
• rollup-plugin-typescript2: 0.10.0

rollup.config.js

import typescript from 'rollup-plugin-typescript2'
import camelCase from 'camel-case'

const pkg = require('./package.json')

export default {
  input: 'src/index.ts',
  output: {
    file: pkg.main,
    format: 'umd',
    name: camelCase(pkg.name),
  },
  watch: {
    include: 'src/**',
  },
  plugins: [
    typescript({
      verbosity: 3,
      tsconfigOverride: {
        compilerOptions: {
          target: 'es5',
          declaration: false,
          declarationDir: null,
        },
      },
      useTsconfigDeclarationDir: true,
    }),
  ],
}

tsconfig.json

{
  "compilerOptions": {
    "module": "esnext",
    "target": "es6",
    "lib": ["es6", "es7", "es2017", "dom"],
    "moduleResolution": "node",
    "declarationDir": "dist/types",
    "declaration": true,
    "allowSyntheticDefaultImports": true,
  },
  "include": [
    "src/*"
  ]
}

[ezolenko]

Ok, I put a minimal fix in for now, try on master.

[ezolenko]

With your options, I end up passing declaration: false, declarationDir: null to typescript.parseJsonConfigFileContent(), and then typescript itself replaces declarationDir with cwd. See values in raw below.

Either this is regression in typescript, or that code path was never fixed. I’ll open a case with them.

rpt2: parsed tsconfig: {
    "options": {
        "module": 5,
        "target": 1,
        "noImplicitAny": true,
        "sourceMap": true,
        "noUnusedParameters": true,
        "noUnusedLocals": true,
        "noImplicitThis": true,
        "diagnostics": true,
        "listFiles": true,
        "pretty": true,
        "moduleResolution": 2,
        "noEmitOnError": false,
        "strictNullChecks": true,
        "forceConsistentCasingInFileNames": true,
        "noImplicitReturns": true,
        "declaration": false,
        "declarationDir": "d:/source/scr/rollup-plugin-typescript2",
        "outDir": "d:\\source\\scr\\rollup-plugin-typescript2",
        "noEmitHelpers": false,
        "importHelpers": true,
        "noResolve": false,
        "noEmit": false,
        "configFilePath": "d:\\source\\scr\\rollup-plugin-typescript2/tsconfig.json"
    },
    "raw": {
        "compilerOptions": {
            "module": "es6",
            "target": "es5",
            "noImplicitAny": true,
            "sourceMap": true,
            "noUnusedParameters": true,
            "noUnusedLocals": true,
            "noImplicitThis": true,
            "diagnostics": true,
            "listFiles": true,
            "pretty": true,
            "moduleResolution": "node",
            "noEmitOnError": false,
            "strictNullChecks": true,
            "forceConsistentCasingInFileNames": true,
            "noImplicitReturns": true,
            "declaration": false,
            "declarationDir": null,
            "outDir": "./build"
        },
        "include": [
            "src/**/*.ts"
        ]
    }
}