GoogleTest

O crate GoogleTest permite assertividade de testes flexĂ­vel usando matchers (correspondentes):

use googletest::prelude::*;

#[googletest::test]
fn test_elements_are() {
    let value = vec!["foo", "bar", "baz"];
    expect_that!(value, elements_are!(eq("foo"), lt("xyz"), starts_with("b")));
}

Se mudarmos o Ășltimo elemento para "!", o teste falha com uma mensagem de erro estruturada apontando o erro:

---- test_elements_are stdout ----
Value of: value
Expected: has elements:
  0. is equal to "foo"
  1. is less than "xyz"
  2. starts with prefix "!"
Actual: ["foo", "bar", "baz"],
  where element #2 is "baz", which does not start with "!"
  at src/testing/googletest.rs:6:5
Error: See failure output above
This slide should take about 5 minutes.

  • GoogleTest nĂŁo faz parte do playground do Rust, entĂŁo vocĂȘ precisa executar este exemplo em um ambiente local. Use cargo add googletest para adicionĂĄ-lo rapidamente a um projeto Cargo existente.

  • A linha use googletest::prelude::*; importa uma sĂ©rie de macros e tipos comumente usados.

  • Isso apenas arranha a superfĂ­cie, hĂĄ muitos matchers embutidos.

  • A particularly nice feature is that mismatches in multi-line strings are shown as a diff:

#[test]
fn test_multiline_string_diff() {
    let haiku = "Memory safety found,\n\
                 Rust's strong typing guides the way,\n\
                 Secure code you'll write.";
    assert_that!(
        haiku,
        eq("Memory safety found,\n\
            Rust's silly humor guides the way,\n\
            Secure code you'll write.")
    );
}

mostra uma diferença usando cores (não mostradas aqui):

    Value of: haiku
Expected: is equal to "Memory safety found,\nRust's silly humor guides the way,\nSecure code you'll write."
Actual: "Memory safety found,\nRust's strong typing guides the way,\nSecure code you'll write.",
  which isn't equal to "Memory safety found,\nRust's silly humor guides the way,\nSecure code you'll write."
Difference(-actual / +expected):
 Memory safety found,
-Rust's strong typing guides the way,
+Rust's silly humor guides the way,
 Secure code you'll write.
  at src/testing/googletest.rs:17:5

  • O crate Ă© uma tradução para Rust do GoogleTest para C++.

  • GoogleTest estĂĄ disponĂ­vel para uso no AOSP.