yoda_test_linter {lintr}

Block obvious "yoda tests"

Description

Yoda tests use ⁠(expected, actual)⁠ instead of the more common ⁠(actual, expected)⁠. This is not always possible to detect statically; this linter focuses on the simple case of testing an expression against a literal value, e.g. ⁠(1L, foo(x))⁠ should be ⁠(foo(x), 1L)⁠.

Usage

yoda_test_linter()

Tags

best_practices, package_development, pkg_testthat, readability

See Also

linters for a complete list of linters available in lintr. https://en.wikipedia.org/wiki/Yoda_conditions

Examples

# will produce lints
lint(
  text = "expect_equal(2, x)",
  linters = yoda_test_linter()
)

lint(
  text = 'expect_identical("a", x)',
  linters = yoda_test_linter()
)

# okay
lint(
  text = "expect_equal(x, 2)",
  linters = yoda_test_linter()
)

lint(
  text = 'expect_identical(x, "a")',
  linters = yoda_test_linter()
)