如何使用内联文档进行 Rust 测试

Question

我正在尝试让 Rust 来测试我的内联文档中的示例。我写了以下代码：

#[derive(Clone)]
#[derive(PartialEq)]
#[derive(Debug)]
enum Color {
    Black = 1,
    Empty = 0,
    White = -1
}
/// Chages Color to the next player
///
/// Returns: White if player is Black, Black if player is White and Empty if
/// player is Empty.
///
/// Examlple
/// ```
/// assert_eq!(flip(&Color::White),Color::Black);
///```

// Invariant Color must represent Black as 1, Empty as 0 and White as -1!
fn flip(player: &Color)->Color{
    let intrepresentation :i8 = (player.clone() as i8) * (-1);
    unsafe{
        std::mem::transmute(intrepresentation)
    }
}
fn  main() {
    assert_eq!(flip(&Color::White),Color::Black);
}
  

然后我跑

rustdoc --test src/main.rs 

这给了我：

running 1 test
test src/main.rs - flip (line 16) ... FAILED

failures:

---- src/main.rs - flip (line 16) stdout ----
error[E0433]: failed to resolve: use of undeclared type or module `Color`
 --> src/main.rs:17:18
  |
3 | assert_eq!(flip(&Color::White),Color::Black);
  |                  ^^^^^ use of undeclared type or module `Color`

error[E0433]: failed to resolve: use of undeclared type or module `Color`
 --> src/main.rs:17:32
  |
3 | assert_eq!(flip(&Color::White),Color::Black);
  |                                ^^^^^ use of undeclared type or module `Color`

error[E0425]: cannot find function `flip` in this scope
 --> src/main.rs:17:12
  |
3 | assert_eq!(flip(&Color::White),Color::Black);
  |            ^^^^ not found in this scope

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0425, E0433.
For more information about an error, try `rustc --explain E0425`.
Couldn't compile the test.

failures:
    src/main.rs - flip (line 16)

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out

我怎样才能让 rustc 找到翻转和颜色。测试在主函数中运行良好。我也尝试过命令：

cargo test

但没有运行任何测试。

我尝试将以下行添加到示例中：

   /// use crate::{flip, Color};

制作：

// Chages Color to the next player
///
/// Returns: White if player is Black, Black if player is White and Empty if
/// player is Empty.
///
/// Examlple
/// ```
/// use crate::{flip, Color};
/// assert_eq!(flip(&Color::White),Color::Black);
///``` 

但这给出了一个错误

martin@martin-laptop:~/test_code$ rustdoc --test src/main.rs 

running 1 test
test src/main.rs - main (line 23) ... FAILED

failures:

---- src/main.rs - main (line 23) stdout ----
error[E0432]: unresolved import `crate::Color`
 --> src/main.rs:24:14
  |
3 | use crate::{ Color};
  |              ^^^^^ no `Color` in the root

error[E0425]: cannot find function `flip` in this scope
 --> src/main.rs:25:12
  |
4 | assert_eq!(flip(&Color::White),Color::Black);
  |            ^^^^ not found in this scope

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0425, E0432.
For more information about an error, try `rustc --explain E0425`.
Couldn't compile the test.

failures:
    src/main.rs - main (line 23)

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out 

我还尝试过将颜色和翻转公开：

#[derive(Clone)]
#[derive(PartialEq)]
#[derive(Debug)]
pub enum Color {
    Black = 1,
    Empty = 0,
    White = -1
}

/// Chages Color to the next player
///
/// Returns: White if player is Black, Black if player is White and Empty if
/// player is Empty.
///
/// Examlple
/// ```
/// use crate::{flip, Color};
/// use std::env;
/// assert_eq!(flip(&Color::White),Color::Black);
///```

// Invariant Color must represent Black as 1, Empty as 0 and White as -1!

pub fn flip(player: &Color)->Color{
    let intrepresentation :i8 = (player.clone() as i8) * (-1);
    unsafe{
        std::mem::transmute(intrepresentation)
    }
}
fn  main() {
    assert_eq!(flip(&Color::White),Color::Black);
}

但这给出了同样的错误。

Answer 1

文档测试（内部测试/// ```）被单独编译为自己的小程序。所以：

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• 他们只能访问公共项目：pub mod, pub fn, pub struct, ...
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• 他们只能访问导出项目供其他板条箱使用的库板条箱main.rs\xe2\x80\x94\xc2\xa0 如果您的程序在其中，那么它是一个二进制板条箱。
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• 您必须完全限定名称或use名称，例如use my_library::Color;.
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如果你想测试不适合这个的东西，那么你应该使用#[test]测试来代替：

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#[test]\nfn flip_test() {\n    assert_eq!(flip(&Color::White), Color::Black);\n}\n

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位于程序中任何位置且具有该属性的任何函数#[test]都将作为测试运行。因此，它们可以访问私有项目，因为它们位于同一模块（或子模块；通常将它们放在tests同一文件中命名的模块中，使用mod tests { ... }）。

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您可以在Rust 编程语言：如何编写测试中找到有关如何编写测试函数和组织测试的更多信息。

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我还尝试过将颜色和翻转公开：

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/// use crate::{flip, Color};\n

\n

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这不起作用，因为crate引用当前的板条箱，对于文档测试来说，它是测试程序，而不是您的主板条箱。

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