jest/prefer-to-have-length

📝 Suggest using toHaveLength().

💼 This rule is enabled in the 🎨 style config.

🔧 This rule is automatically fixable by the --fix CLI option.

In order to have a better failure message, toHaveLength() should be used upon asserting expectations on objects length property.

Rule details

This rule triggers a warning if toBe(), toEqual() or toStrictEqual() is used to assert objects length property.

expect(files.length).toBe(1);

This rule is enabled by default.

The following patterns are considered warnings:

expect(files.length).toBe(1);

expect(files.length).toEqual(1);

expect(files.length).toStrictEqual(1);

The following pattern is not warning:

expect(files).toHaveLength(1);