Source files with only type declarations don't get declarations generated

[houfio]

What happens and why it is wrong

When building a project with files that only have type declarations, the declarations don't get generated for those files. Using tsc generated the declarations and declaration maps as expected.

Versions

• typescript: 3.0.1
• rollup: 0.64.1
• rollup-plugin-typescript2: 0.16.1

rollup.config.js

import { dirname, join } from 'path';
import commonjs from 'rollup-plugin-commonjs';
import typescript from 'rollup-plugin-typescript2';
import resolve from 'rollup-plugin-node-resolve';

const root = process.cwd();
const { main, module, types, dependencies = {}, peerDependencies = {} } = require(join(root, 'package.json'));

export default {
  input: join(root, 'src/index.ts'),
  output: [
    {
      file: join(root, main),
      format: 'cjs',
      sourcemap: true
    },
    {
      file: join(root, module),
      format: 'es',
      sourcemap: true
    }
  ],
  external: [
    ...Object.keys(dependencies),
    ...Object.keys(peerDependencies)
  ],
  plugins: [
    resolve(),
    typescript({
      clean: true,
      useTsconfigDeclarationDir: true,
      tsconfigOverride: {
        compilerOptions: {
          rootDir: join(root, 'src'),
          declarationDir: join(root, dirname(types))
        }
      }
    }),
    commonjs()
  ]
};

tsconfig.json

{
  "compilerOptions": {
    "module": "esnext",
    "target": "es5",
    "lib": [
      "es6",
      "dom"
    ],
    "jsx": "react",
    "moduleResolution": "node",
    "declaration": true,
    "declarationMap": true,
    "sourceMap": true,
    "strict": true,
    "allowSyntheticDefaultImports": true
  },
  "include": [
    "src/"
  ]
}

package.json

{
  "scripts": {
    "prebuild": "lerna exec -- rimraf lib",
    "build": "lerna exec --parallel -- rollup --config \\$LERNA_ROOT_PATH/rollup.config.js"
  },
  "devDependencies": {
    "lerna": "^3.1.2",
    "rimraf": "^2.6.2",
    "rollup": "^0.64.1",
    "rollup-plugin-commonjs": "^9.1.5",
    "rollup-plugin-node-resolve": "^3.3.0",
    "rollup-plugin-typescript2": "^0.16.1",
    "typescript": "^3.0.1"
  }
}

plugin output with verbosity 3

Log

lerna notice cli v3.1.4
lerna info exec in 1 package: "rollup --config $LERNA_ROOT_PATH/rollup.config.js"
@: <path>/src/index.ts → lib/index.js, lib/index.es.js...
@: rpt2: typescript version: 3.0.1
@: rpt2: tslib version: 1.9.3
@: rpt2: rollup-plugin-typescript2 version: 0.16.1
@: rpt2: plugin options:
@: {
@:     "verbosity": 3,
@:     "clean": true,
@:     "useTsconfigDeclarationDir": true,
@:     "tsconfigOverride": {
@:         "compilerOptions": {
@:             "rootDir": "<path>/src",
@:             "declarationDir": "<path>/lib"
@:         }
@:     },
@:     "check": true,
@:     "cacheRoot": "<path>/.rpt2_cache",
@:     "include": [
@:         "*.ts+(|x)",
@:         "**/*.ts+(|x)"
@:     ],
@:     "exclude": [
@:         "*.d.ts",
@:         "**/*.d.ts"
@:     ],
@:     "abortOnError": true,
@:     "rollupCommonJSResolveHack": false,
@:     "typescript": "version 3.0.1",
@:     "transformers": [],
@:     "tsconfigDefaults": {}
@: }
@: rpt2: rollup config:
@: {
@:     "external": [
@:         "react",
@:         "",
@:         ""
@:     ],
@:     "inlineDynamicImports": false,
@:     "input": "<path>/src/index.ts",
@:     "chunkGroupingSize": 5000,
@:     "perf": false,
@:     "plugins": [
@:         {
@:             "name": "node-resolve"
@:         },
@:         {
@:             "name": "rpt2"
@:         },
@:         {
@:             "name": "commonjs"
@:         }
@:     ],
@:     "entry": "<path>/src/index.ts"
@: }
@: rpt2: built-in options overrides: {
@:     "noEmitHelpers": false,
@:     "importHelpers": true,
@:     "noResolve": false,
@:     "noEmit": false,
@:     "inlineSourceMap": false,
@:     "outDir": "<path>/.rpt2_cache/placeholder",
@:     "moduleResolution": 2
@: }
@: rpt2: parsed tsconfig: {
@:     "options": {
@:         "module": 6,
@:         "target": 1,
@:         "lib": [
@:             "lib.es2015.d.ts",
@:             "lib.dom.d.ts"
@:         ],
@:         "jsx": 2,
@:         "moduleResolution": 2,
@:         "declaration": true,
@:         "declarationMap": true,
@:         "sourceMap": true,
@:         "strict": true,
@:         "allowSyntheticDefaultImports": true,
@:         "rootDir": "<path>/src",
@:         "declarationDir": "<path>/lib",
@:         "configFilePath": "<path>/tsconfig.json",
@:         "noEmitHelpers": false,
@:         "importHelpers": true,
@:         "noResolve": false,
@:         "noEmit": false,
@:         "inlineSourceMap": false,
@:         "outDir": "<path>/.rpt2_cache/placeholder"
@:     },
@:     "fileNames": [],
@:     "typeAcquisition": {
@:         "enable": false,
@:         "include": [],
@:         "exclude": []
@:     },
@:     "raw": {
@:         "compilerOptions": {
@:             "module": "esnext",
@:             "target": "es5",
@:             "lib": [
@:                 "es6",
@:                 "dom"
@:             ],
@:             "jsx": "react",
@:             "moduleResolution": "node",
@:             "declaration": true,
@:             "declarationMap": true,
@:             "sourceMap": true,
@:             "strict": true,
@:             "allowSyntheticDefaultImports": true,
@:             "rootDir": "<path>/src",
@:             "declarationDir": "<path>/lib"
@:         },
@:         "include": [
@:             "src/"
@:         ],
@:         "compileOnSave": false
@:     },
@:     "errors": [
@:         {
@:             "messageText": "No inputs were found in config file '<path>/tsconfig.json'. Specified 'include' paths were '[\"src/\"]' and 'exclude' paths were '[\"<path>/lib\"]'.",
@:             "category": 1,
@:             "code": 18003
@:         }
@:     ],
@:     "wildcardDirectories": {
@:         "<path>/src/": 1
@:     },
@:     "compileOnSave": false,
@:     "configFileSpecs": {
@:         "includeSpecs": [
@:             "src/"
@:         ],
@:         "excludeSpecs": [
@:             "<path>/lib"
@:         ],
@:         "validatedIncludeSpecs": [
@:             "src/"
@:         ],
@:         "validatedExcludeSpecs": [
@:             "<path>/lib"
@:         ],
@:         "wildcardDirectories": {
@:             "<path>/src/": 1
@:         }
@:     }
@: }
@: rpt2: included:
@: '[
@:     "*.ts+(|x)",
@:     "**/*.ts+(|x)"
@: ]'
@: rpt2: excluded:
@: '[
@:     "*.d.ts",
@:     "**/*.d.ts"
@: ]'
@: rpt2: Ambient types:
@: rpt2:     <path>/node_modules/@types/estree/index.d.ts
@: rpt2:     <path>/node_modules/@types/node/index.d.ts
@: rpt2:     <path>/node_modules/@types/prop-types/index.d.ts
@: rpt2:     <path>/node_modules/@types/react/index.d.ts
@: rpt2: ambient types changed, redoing all semantic diagnostics
@: rpt2: transpiling '<path>/src/index.ts'
@: rpt2:     cache: 'cb5a72ce1d9ca58fa672e942573d3ba70cc6e65e'
@: rpt2:     cache miss
@: rpt2:     cache: 'cb5a72ce1d9ca58fa672e942573d3ba70cc6e65e'
@: rpt2:     cache miss
@: rpt2:     cache: 'cb5a72ce1d9ca58fa672e942573d3ba70cc6e65e'
@: rpt2:     cache miss
@: rpt2: generated declarations for '<path>/src/index.ts'
@: rpt2: dependency '<path>/src/constants.ts'
@: rpt2:     imported by '<path>/src/index.ts'
@: rpt2: resolving './constants'
@: rpt2:     to '<path>/src/constants.ts'
@: rpt2: transpiling '<path>/src/constants.ts'
@: rpt2:     cache: 'c0821b0be34b449d7f93ba52a5b0708ea09e39f7'
@: rpt2:     cache miss
@: rpt2:     cache: 'c0821b0be34b449d7f93ba52a5b0708ea09e39f7'
@: rpt2:     cache miss
@: rpt2:     cache: 'c0821b0be34b449d7f93ba52a5b0708ea09e39f7'
@: rpt2:     cache miss
@: rpt2: generated declarations for '<path>/src/constants.ts'
@: rpt2: generating target 1
@: rpt2: rolling caches
@: rpt2: writing declarations for '<path>/src/index.ts' to '<path>/lib/index.d.ts'
@: rpt2: writing declarations for '<path>/src/index.ts' to '<path>/lib/index.d.ts.map'
@: rpt2: writing declarations for '<path>/src/constants.ts' to '<path>/lib/constants.d.ts'
@: rpt2: writing declarations for '<path>/src/constants.ts' to '<path>/lib/constants.d.ts.map'
@: rpt2: generating target 2
@: rpt2: rolling caches
@: rpt2: writing declarations for '<path>/src/index.ts' to '<path>/lib/index.d.ts'
@: rpt2: writing declarations for '<path>/src/index.ts' to '<path>/lib/index.d.ts.map'
@: rpt2: writing declarations for '<path>/src/constants.ts' to '<path>/lib/constants.d.ts'
@: rpt2: writing declarations for '<path>/src/constants.ts' to '<path>/lib/constants.d.ts.map'
@: created lib/index.js, lib/index.es.js in 1.2s

[ezolenko]

Check out this line in the verbose log:

"messageText": "No inputs were found in config file '<path>/tsconfig.json'. Specified 'include' paths were '[\"src/\"]' and 'exclude' paths were '[\"<path>/lib\"]'.",

Not sure why it didn't print it out as an actual error, but that must have something to do with it. Type-only ts files are invisible to rollup, so the plugin relies on include list in tsconfig to get the missing files to extract declarations from.

This is different from plugin's own include/exclude values -- those are only used to filter out files that rollup sees.

[houfio]

I see! Adding the followijg to the tsconfig overrides fixes the problem:

        include: [
          join(root, 'src')
        ]

TypeScript seems to use the path relative to the tsconfig and not the cwd.
I'd be great if the plugin actually notified the users about any ts config errors. Can I make a PR for that?

[ezolenko]

Sure, PRs are welcome. Check parse-tsconfig.ts for a starting point. Plugin should already print out hard parsing errors, so I suppose this is some kind of warning that goes in a separate channel.

[agilgur5]

See #211 for the root cause of this. The original intent of the issue is mostly the same as that one, but then it ended up being a bugfix for not reporting tsconfig errors properly.
Fixing the tsconfig error allowed a workaround from #24 to get this to work, but the root cause of both is #211