Runtime error when using as `configPlugin` with `"declarationMap": true`

[agilgur5]

What happens and why it is wrong

A runtime error occurs when your tsconfig.json has "declarationMap": true and you use this plugin as a configPlugin.

Per the error below, it occurs on this line in the code. Specifically, it appears that declarationDir is undefined because in the case of a configPlugin, Rollup's output isn't set what-so-ever, so output.file and output.dir are both undefined (see below for verbosity that verifies this).

Ironically, I actually wrote this code myself in #221 so I could write a PR to fix this myself. I think a default declarationDir equivalent to cwd would probably suffice for this -- let me know if you think a different solution makes sense, otherwise I could write that up pretty quickly.

To be specific, rpts2 only errors when declarationMap is turned on, everything else doesn't seem to be impacted, so things like emitFile etc still work when used as a configPlugin.
Current workaround is to disable declarationMap in tsconfig (or tsconfigOverrides) specifically when using as a configPlugin only.

Error:

$ rollup -c rollup.config.ts --configPlugin rollup-plugin-typescript2
[!] (plugin rpt2) TypeError: The "from" argument must be of type string. Received undefined
TypeError [ERR_INVALID_ARG_TYPE]: The "from" argument must be of type string. Received undefined
    at new NodeError (internal/errors.js:322:7)
    at validateString (internal/validators.js:124:11)
    at Object.relative (path.js:1167:5)
    at <project>/node_modules/rollup-plugin-typescript2/src/index.ts:383:25
    at Array.map (<anonymous>)
    at emitDeclaration (<project>/node_modules/rollup-plugin-typescript2/src/index.ts:380:47)
    at <project>/node_modules/rollup-plugin-typescript2/src/index.ts:401:5
    at <project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:4967:15
    at baseForOwn (<project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:3032:24)
    at <project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:4936:18

Environment

Versions

  npmPackages:
    rollup: ^2.70.2 => 2.70.2 
    rollup-plugin-typescript2: ^0.31.2 => 0.31.2 
    typescript: ^4.6.3 => 4.6.3 

rollup.config.ts

:

My rollup config actually isn't relevant as I'm actually not using rpts2 in the rollup config, just for parsing the config itself (as I wrote it in TS)

tsconfig.json

:

(slightly simplified version as I actually have multiple tsconfigs that extend each other)

{
  // only build the rollup config for this parse through
  "files": ["rollup.config.ts"],
  // https://github.com/tsconfig/bases
  "extends": "@tsconfig/strictest/tsconfig.json",
  // see https://www.typescriptlang.org/tsconfig to better understand tsconfigs
  "compilerOptions": {
    // output to dist/ dir
    "outDir": "dist/",
    // output .d.ts declaration files for consumers
    "declaration": true,
    // output .d.ts.map declaration map files for consumers
    "declarationMap": true,
    // output .js.map sourcemap files for consumers
    "sourceMap": true,
    // use Node's module resolution algorithm, instead of the legacy TS one
    "moduleResolution": "node",
    // resolve JSON files
    "resolveJsonModule": true,
    // transpile JSX to React.createElement
    "jsx": "react",
    // ignored during builds, but commonly used when type-checking with `tsc`
    "noEmit": true,
  }
}

package.json

:

Think the envinfo output above is good enough; I've found the error in any case.

plugin output with verbosity 3

:

rpt2: built-in options overrides: {
    "noEmitHelpers": false,
    "importHelpers": true,
    "noResolve": false,
    "noEmit": false,
    "inlineSourceMap": false,
    "outDir": "<project>/node_modules/.cache/rollup-plugin-typescript2/placeholder",
    "moduleResolution": 2,
    "allowNonTsExtensions": true,
    "module": 5
}
rpt2: parsed tsconfig: {
    "options": {
        "strict": true,
        "allowUnusedLabels": false,
        "allowUnreachableCode": false,
        "exactOptionalPropertyTypes": true,
        "noFallthroughCasesInSwitch": true,
        "noImplicitOverride": true,
        "noImplicitReturns": true,
        "noPropertyAccessFromIndexSignature": true,
        "noUncheckedIndexedAccess": true,
        "noUnusedLocals": true,
        "noUnusedParameters": true,
        "importsNotUsedAsValues": 2,
        "checkJs": true,
        "esModuleInterop": true,
        "skipLibCheck": true,
        "forceConsistentCasingInFileNames": true,
        "outDir": "<project>/node_modules/.cache/rollup-plugin-typescript2/placeholder",
        "declaration": true,
        "declarationMap": true,
        "sourceMap": true,
        "moduleResolution": 2,
        "resolveJsonModule": true,
        "jsx": 2,
        "noEmit": false,
        "configFilePath": "<project>/tsconfig.json",
        "noEmitHelpers": false,
        "importHelpers": true,
        "noResolve": false,
        "inlineSourceMap": false,
        "allowNonTsExtensions": true,
        "module": 5
    },
    "fileNames": [
        "<project>/rollup.config.ts"
    ],
    "typeAcquisition": {
        "enable": false,
        "include": [],
        "exclude": []
    },
    "raw": {
        "extends": "@tsconfig/strictest/tsconfig.json",
        "exclude": [
            "node_modules/",
            "dist/",
            "coverage/",
            "example/"
        ],
        "compilerOptions": {
            "outDir": "dist/",
            "declaration": true,
            "declarationMap": true,
            "sourceMap": true,
            "moduleResolution": "node",
            "resolveJsonModule": true,
            "jsx": "react",
            "noEmit": true
        },
        "files": [
            "rollup.config.ts"
        ],
        "compileOnSave": false
    },
    "errors": [],
    "wildcardDirectories": {},
    "compileOnSave": false
}
rpt2: typescript version: 4.6.3
rpt2: tslib version: 2.3.1
rpt2: rollup version: 2.70.2
rpt2: rollup-plugin-typescript2 version: 0.31.2
rpt2: plugin options:
{
    "verbosity": 3,
    "check": true,
    "clean": false,
    "cacheRoot": "<project>/node_modules/.cache/rollup-plugin-typescript2",
    "include": [
        "*.ts+(|x)",
        "**/*.ts+(|x)"
    ],
    "exclude": [
        "*.d.ts",
        "**/*.d.ts"
    ],
    "abortOnError": true,
    "rollupCommonJSResolveHack": false,
    "useTsconfigDeclarationDir": false,
    "transformers": [],
    "tsconfigDefaults": {},
    "objectHashIgnoreUnknownHack": false,
    "cwd": "<project>",
    "typescript": "version 4.6.3"
}
rpt2: rollup config:
{
    "input": "<project>/rollup.config.ts",
    "plugins": [
        {
            "name": "rpt2"
        }
    ],
    "treeshake": false
}
rpt2: tsconfig path: <project>/tsconfig.json
rpt2: included:
[
    "*.ts+(|x)",
    "**/*.ts+(|x)"
]
rpt2: excluded:
[
    "*.d.ts",
    "**/*.d.ts"
]
rpt2: Ambient types:
rpt2:     <project>/node_modules/@types/babel__core/index.d.ts
rpt2:     <project>/node_modules/@types/babel__generator/index.d.ts
rpt2:     <project>/node_modules/@types/babel__template/index.d.ts
rpt2:     <project>/node_modules/@types/babel__traverse/index.d.ts
rpt2:     <project>/node_modules/@types/cheerio/index.d.ts
rpt2:     <project>/node_modules/@types/enzyme/index.d.ts
rpt2:     <project>/node_modules/@types/estree/index.d.ts
rpt2:     <project>/node_modules/@types/graceful-fs/index.d.ts
rpt2:     <project>/node_modules/@types/istanbul-lib-coverage/index.d.ts
rpt2:     <project>/node_modules/@types/istanbul-lib-report/index.d.ts
rpt2:     <project>/node_modules/@types/istanbul-reports/index.d.ts
rpt2:     <project>/node_modules/@types/json5/index.d.ts
rpt2:     <project>/node_modules/@types/node/ts3.2/index.d.ts
rpt2:     <project>/node_modules/@types/parse-json/index.d.ts
rpt2:     <project>/node_modules/@types/prettier/index.d.ts
rpt2:     <project>/node_modules/@types/prop-types/index.d.ts
rpt2:     <project>/node_modules/@types/react/index.d.ts
rpt2:     <project>/node_modules/@types/resolve/index.d.ts
rpt2:     <project>/node_modules/@types/scheduler/index.d.ts
rpt2:     <project>/node_modules/@types/signature_pad/index.d.ts
rpt2:     <project>/node_modules/@types/stack-utils/index.d.ts
rpt2:     <project>/node_modules/@types/yargs/index.d.ts
rpt2:     <project>/node_modules/@types/yargs-parser/index.d.ts
rpt2: ambient types changed, redoing all semantic diagnostics
rpt2: transpiling '<project>/rollup.config.ts'
rpt2:     cache: '<project>/node_modules/.cache/rollup-plugin-typescript2/rpt2_886b5474ceab46316c300049e28ace720638ad6b/code/cache/8ff12b6a0f6d14ec54898a8a47dd4d86c8c3c981'
rpt2:     cache miss
rpt2:     cache: '<project>/node_modules/.cache/rollup-plugin-typescript2/rpt2_886b5474ceab46316c300049e28ace720638ad6b/syntacticDiagnostics/cache/8ff12b6a0f6d14ec54898a8a47dd4d86c8c3c981'
rpt2:     cache miss
rpt2:     cache: '<project>/node_modules/.cache/rollup-plugin-typescript2/rpt2_886b5474ceab46316c300049e28ace720638ad6b/semanticDiagnostics/cache/8ff12b6a0f6d14ec54898a8a47dd4d86c8c3c981'
rpt2:     cache miss
rpt2: generated declarations for '<project>/rollup.config.ts'
rpt2: generating target 1
rpt2: rolling caches
rpt2: emitting declarations for '<project>/rollup.config.ts' to 'rollup.config.d.ts'
[!] (plugin rpt2) TypeError: The "from" argument must be of type string. Received undefined
TypeError [ERR_INVALID_ARG_TYPE]: The "from" argument must be of type string. Received undefined
    at new NodeError (internal/errors.js:322:7)
    at validateString (internal/validators.js:124:11)
    at Object.relative (path.js:1167:5)
    at <project>/node_modules/rollup-plugin-typescript2/src/index.ts:383:25
    at Array.map (<anonymous>)
    at emitDeclaration (<project>/node_modules/rollup-plugin-typescript2/src/index.ts:380:47)
    at <project>/node_modules/rollup-plugin-typescript2/src/index.ts:401:5
    at <project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:4967:15
    at baseForOwn (<project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:3032:24)
    at <project>/node_modules/rollup-plugin-typescript2/node_modules/lodash/lodash.js:4936:18

[ezolenko]

Does this work if you set useTsconfigDeclarationDir in plugin options to true?

[agilgur5]

As expected (since the erroring code is in the else when useTsconfigDeclarationDir is falsey), it does indeed work. I thought it might cause TS to actually write stuff since it's no longer controlled by Rollup in that case, but I think since I have noEmit set, it actually didn't output a rollup.config.js etc.
So that's another viable workaround if one has noEmit in their tsconfig set (if they're using rpts2 both as plugin and configPlugin, they may not).

Think it would still be good to get a real fix in as this is an actual unexpected edge case that my code didn't handle

[agilgur5]

Released in 0.32.0 🎉

Double-checked that the release works in one of my libraries as well 🙂