Crashes when `expect` with no following statement.

[garyking]

If you have code like expect() without anything after, like toBe, then it crashes the linter. It shouldn't crash the linter. I imagine Jest would do enough to notify you that something is wrong, or at least the linter should indicate that the following statement is missing.

Sample code:

test('test', () => {
  expect('a');
})

Which results in the following error when linting:

TypeError: Cannot read property 'name' of undefined
Occurred while linting asdf.test.js:2
    at methodName (/usr/local/lib/node_modules/eslint-plugin-jest/lib/rules/util.js:66:40)
    at expectToBeCase (/usr/local/lib/node_modules/eslint-plugin-jest/lib/rules/util.js:42:140)
    at CallExpression (/usr/local/lib/node_modules/eslint-plugin-jest/lib/rules/prefer-to-be-null.js:25:45)
    at listeners.(anonymous function).forEach.listener (/usr/local/lib/node_modules/eslint/lib/util/safe-emitter.js:45:58)
    at Array.forEach (<anonymous>)
    at Object.emit (/usr/local/lib/node_modules/eslint/lib/util/safe-emitter.js:45:38)
    at NodeEventGenerator.applySelector (/usr/local/lib/node_modules/eslint/lib/util/node-event-generator.js:251:26)
    at NodeEventGenerator.applySelectors (/usr/local/lib/node_modules/eslint/lib/util/node-event-generator.js:280:22)
    at NodeEventGenerator.enterNode (/usr/local/lib/node_modules/eslint/lib/util/node-event-generator.js:294:14)
    at CodePathAnalyzer.enterNode (/usr/local/lib/node_modules/eslint/lib/code-path-analysis/code-path-analyzer.js:632:23)

[G-Rath]

This shouldn't be happening! 😱

I'm going to make a quick patching PR, but this is one of the problems that'll be fixed once we've finished converting to TypeScript (I've rewritten all the guards, for exactly this sort of use-case).

I imagine Jest would do enough to notify you that something is wrong, or at least the linter should indicate that the following statement is missing.

This should be covered by the valid-expect rule - All other rules should just gracefully bail under the idea that valid-expect will handle making noise about the validity of an expect.

(I can't actually remember if we consider expect(<arg>) as "invalid", as it'll run just fine, even if it is completely meaningless, but it definitely shouldn't cause a crash)

[SimenB]

It should be flagged by valid-expect, yes. Jest itself has no way of detecting whether a matcher is used or not

[SimenB]

🎉 This issue has been resolved in version 22.14.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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