TypeError: Path must be a string. Received undefined on v1.6.1 on node 6

[nfcampos]

I get this stacktrace on running eslint on node 6

TypeError: Path must be a string. Received undefined
    at assertPath (path.js:7:11)
    at Object.extname (path.js:1429:5)
    at EventEmitter.checkFileExtension (/Users/nuno/cp/j2/node_modules/eslint-plugin-import/lib/rules/extensions.js:43:36)
    at emitOne (events.js:101:20)
    at EventEmitter.emit (events.js:188:7)
    at NodeEventGenerator.enterNode (/Users/nuno/cp/j2/node_modules/eslint/lib/util/node-event-generator.js:40:22)
    at CodePathAnalyzer.enterNode (/Users/nuno/cp/j2/node_modules/eslint/lib/code-path-analysis/code-path-analyzer.js:607:23)
    at CommentEventGenerator.enterNode (/Users/nuno/cp/j2/node_modules/eslint/lib/util/comment-event-generator.js:97:23)
    at Controller.traverser.traverse.enter (/Users/nuno/cp/j2/node_modules/eslint/lib/eslint.js:886:36)
    at Controller.__execute (/Users/nuno/cp/j2/node_modules/estraverse/estraverse.js:397:31)

I guess on this line https://github.com/benmosher/eslint-plugin-import/blob/master/src/rules/extensions.js#L27 resolve is returning undefined because it doesn't find the module and as such path.extname throws on the next line

[benmosher]

Ah, right. It's weird none of the tests are failing on that in CI. Also resolve shouldn't return undefined in general, IIRC.

Can you post your eslintrc settings and (if possible) the line of code that's causing this? (if you're able to trace it back)

Also hopefully #296 fixes this anyway.

[nfcampos]

I'll try to find some time to find the line that is causing this. In the meantime here's the eslintrc:

{
  "extends": [
    "eslint:recommended",
    "plugin:react/recommended",
    "plugin:import/errors",
    "plugin:import/warnings",
    "plugin:ava/recommended"
  ],
  "parser": "babel-eslint",
  "parserOptions": {
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true,
      "experimentalObjectRestSpread": true
    },
    "ecmaVersion": 6
  },
  "rules": {
    "comma-dangle": 0,
    "no-unused-vars": 1,
    "no-console": 0,
    "jsx-quotes": [1, "prefer-single"],
    "react/display-name": [0],
    "react/prop-types": [0],
    "import/no-extraneous-dependencies": 2,
    "import/extensions": 1,
    "import/order": 1,
  },
  "env": {
    "browser": true,
    "node": true,
    "es6": true
  },
  "plugins": [
    "import",
    "react",
    "ava"
  ],
  "settings": {
    "import/ignore": [
      "node_modules",
      \.css$
    ],
    import/resolver: webpack
  }
}

[benmosher]

I think you're probably right, it's likely an unresolved import. I double-checked, and #296 should fix it; it coalesces back to the source file's import path if it is unresolved.

So probably no need to look closely unless #296 doesn't actually fix it.

[singles]

FYI: In my case it's TypeError: Path must be a string. Received null. Using master solves that issue.

[benmosher]

Just published v1.7.0, should resolve this. Let me know if it doesn't and I can reopen. 😄