False positives when using multiple package.json files

[geraintwhite]

Bug Description

When using multiple package.json files in folders of a project depcheck cannot properly check imports within those folders.

I am using multiple package.json files to achieve absolute import paths (because babel-plugin-module-resolver doesn't work well with react-native).

• I have my main package.json in the project root containing all my dependencies.
• I also have a package.json in the app directory (which is where most of the code is), containing only { "name": "app" }.
• This allows me to import files using the import from 'app/modules/...' syntax anywhere in the project.

The problem is that running depcheck in the root of the project reports that every dependency used in the app folder is unused, but when I remove app/package.json it reports the dependency usage correctly.

Versions

• node -v: v12.4.0
• npm -v: 6.9.0
• depcheck --version: 0.8.4

JSON Output

With app/package.json file

{
  "dependencies": [
    "@bt-fv/react-native-liblinphone",
    "@react-native-community/push-notification-ios",
    "color",
    "jail-monkey",
    "libphonenumber-js",
    "moment",
    "react-dom",
    "react-native-action-sheet",
    "react-native-adobe-analytics",
    "react-native-android-open-settings",
    "react-native-audio-record",
    "react-native-audiowaveform",
    "react-native-callkeep",
    "react-native-collapsible",
    "react-native-contacts",
    "react-native-device-info",
    "react-native-fs",
    "react-native-gesture-handler",
    "react-native-keyboard-aware-scroll-view",
    "react-native-material-dropdown",
    "react-native-modal",
    "react-native-offline",
    "react-native-push-notification",
    "react-native-reanimated",
    "react-native-share",
    "react-native-slider",
    "react-native-splash-screen",
    "react-native-swipeable",
    "react-native-tab-view",
    "react-native-voip-push-notification",
    "react-native-web",
    "react-native-web-modal",
    "react-native-webview",
    "react-native-xml2js",
    "react-navigation",
    "react-navigation-stack",
    "react-navigation-tabs",
    "react-redux",
    "redux",
    "redux-persist",
    "redux-thunk",
    "uuid",
    "wavesurfer.js"
  ],
  "devDependencies": [
    "@babel/core",
    "@svgr/webpack",
    "babel-loader",
    "babel-preset-react-app",
    "buffer",
    "case-sensitive-paths-webpack-plugin",
    "chalk",
    "copy-webpack-plugin",
    "dotenv",
    "dotenv-expand",
    "electron-devtools-installer",
    "eslint-loader",
    "file-loader",
    "fs-extra",
    "html-webpack-plugin",
    "husky",
    "metro-react-native-babel-preset",
    "node-loader",
    "object-assign",
    "progress-bar-webpack-plugin",
    "promise",
    "raf",
    "react-dev-utils",
    "react-shallow-testutils",
    "react-test-renderer",
    "redux-devtools-extension",
    "terser-webpack-plugin",
    "url-loader",
    "wait-on",
    "webpack",
    "webpack-dev-server",
    "webpack-merge",
    "whatwg-fetch"
  ],
  "missing": {
    "app": [...],
    "metro-config": [...]
  },
  "using": {
    "babel-eslint": [...],
    "eslint-plugin-jest": [...],
    "eslint-plugin-react": [...],
    "eslint-plugin-react-native": [...],
    "eslint-plugin-import": [...],
    "eslint-plugin-flowtype": [...],
    "eslint": [...],
    "@react-native-community/async-storage": [...],
    "react": [...],
    "react-native": [...],
    "react-native-permissions": [...],
    "react-native-sentry": [...],
    "app": [...],
    "react-native-config": [...],
    "metro-config": [...],
    "react-native-svg-transformer": [...],
    "react-native-svg": [...],
    "check-node-version": [...],
    "concurrently": [...],
    "electron": [...],
    "electron-packager": [...],
    "electron-rebuild": [...],
    "eslint-watch": [...],
    "flow-bin": [...],
    "flow-watch": [...],
    "jest": [...],
    "jetifier": [...],
    "react-native-version": [...],
    "@bsft/mock-data-seed": [...]
  }
}

Without app/package.json file

{
  "dependencies": [],
  "devDependencies": [
    "buffer",
    "husky",
    "metro-react-native-babel-preset",
    "wait-on"
  ],
  "missing": {
    "app": [...],
    "prop-types": [...],
    "raven-js": [...],
    "metro-config": [...]
  },
  "using": {
    "babel-eslint": [...],
    "eslint-plugin-jest": [...],
    "eslint-plugin-react": [...],
    "eslint-plugin-react-native": [...],
    "eslint-plugin-import": [...],
    "eslint-plugin-flowtype": [...],
    "eslint": [...],
    "@react-native-community/async-storage": [...],
    "react": [...],
    "react-native": [...],
    "react-native-permissions": [...],
    "react-test-renderer": [...],
    "app": [...],
    "react-shallow-testutils": [...],
    "react-native-config": [...],
    "react-navigation": [...],
    "react-redux": [...],
    "redux": [...],
    "react-native-swipeable": [...],
    "moment": [...],
    "uuid": [...],
    "react-native-keyboard-aware-scroll-view": [...],
    "react-native-collapsible": [...],
    "react-native-tab-view": [...],
    "react-native-gesture-handler": [...],
    "react-native-reanimated": [...],
    "react-native-adobe-analytics": [...],
    "react-native-action-sheet": [...],
    "react-native-webview": [...],
    "react-native-share": [...],
    "react-native-material-dropdown": [...],
    "color": [...],
    "react-dom": [...],
    "wavesurfer.js": [...],
    "react-native-audiowaveform": [...],
    "react-native-audio-record": [...],
    "react-native-modal": [...],
    "react-native-slider": [...],
    "react-native-svg": [...],
    "jail-monkey": [...],
    "prop-types": [...],
    "react-native-offline": [...],
    "redux-persist": [...],
    "react-native-splash-screen": [...],
    "react-native-callkeep": [...],
    "react-native-contacts": [...],
    "react-native-sentry": [...],
    "react-native-voip-push-notification": [...],
    "react-native-push-notification": [...],
    "@react-native-community/push-notification-ios": [...],
    "@bt-fv/react-native-liblinphone": [...],
    "react-native-fs": [...],
    "react-navigation-stack": [...],
    "react-navigation-tabs": [...],
    "redux-devtools-extension": [...],
    "redux-thunk": [...],
    "react-native-device-info": [...],
    "react-native-xml2js": [...],
    "react-native-android-open-settings": [...],
    "libphonenumber-js": [...],
    "electron": [...],
    "promise": [...],
    "whatwg-fetch": [...],
    "object-assign": [...],
    "raf": [...],
    "react-dev-utils": [...],
    "webpack": [...],
    "progress-bar-webpack-plugin": [...],
    "url-loader": [...],
    "@svgr/webpack": [...],
    "babel-loader": [...],
    "babel-preset-react-app": [...],
    "file-loader": [...],
    "@babel/core": [...],
    "dotenv-expand": [...],
    "dotenv": [...],
    "webpack-merge": [...],
    "case-sensitive-paths-webpack-plugin": [...],
    "html-webpack-plugin": [...],
    "node-loader": [...],
    "terser-webpack-plugin": [...],
    "copy-webpack-plugin": [...],
    "eslint-loader": [...],
    "react-native-web": [...],
    "react-native-web-modal": [...],
    "fs-extra": [...],
    "raven-js": [...],
    "electron-devtools-installer": [...],
    "chalk": [...],
    "webpack-dev-server": [...],
    "metro-config": [...],
    "react-native-svg-transformer": [...],
    "check-node-version": [...],
    "concurrently": [...],
    "electron-packager": [...],
    "electron-rebuild": [...],
    "eslint-watch": [...],
    "flow-bin": [...],
    "flow-watch": [...],
    "jest": [...],
    "jetifier": [...],
    "react-native-version": [...],
    "@bsft/mock-data-seed": [...]
  }
}

[rumpl]

Hi @grit96 thanks for reporting this.

To be honest I don't think I'll work on this. It's a hack for making some babel plugin work, it would be better if the babel plugin fixed this issue so that you don't have to create random pakage.json files in your project.