GoogleTest

The GoogleTest crate allows for flexible test assertions using matchers:

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"))); }

如果我们将最后一个元素更改为 "!",测试将失败,并会提供详细的错误消息来指出错误的位置:

---- 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

Speaker Notes

This slide should take about 5 minutes.
  • GoogleTest 不是 Rust Playground 的一部分,因此您需要在本地环境中运行此示例。使用 cargo add googletest 快速将其添加到现有 Cargo 项目中。

  • use googletest::prelude::*; 行会导入一些 常用的宏和类型

  • 这只是冰山一角,还有很多内置匹配器。

  • 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.") ); }

显示用颜色标识的差异(此处未显示颜色):

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