GoogleTest
GoogleTest クレートにより、マッチャーを使用した柔軟なテスト アサーションが可能になります。
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")));
}
最後の要素を "!"
に変更すると、テストは失敗し、エラー箇所を示す構造化されたエラー メッセージが表示されます。
---- 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 は Rust プレイグラウンドの一部ではないため、この例はローカル環境で実行する必要があります。
cargo add googletest
を使用して、既存の Cargo プロジェクトにすばやく追加します。 -
use googletest::prelude::*;
行は、一般的に使用されるマクロと型をインポートします。 -
This just scratches the surface, there are many builtin matchers. Consider going through the first chapter of "Advanced testing for Rust applications", a self-guided Rust course: it provides a guided introduction to the library, with exercises to help you get comfortable with
googletest
macros, its matchers and its overall philosophy. -
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.")
);
}
これにより、差分が色分けされます(ここでは色分けされていません)。
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
- このクレートは GoogleTest for C++ をRustに移植したものです。