googletest 0.14.2

// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// There are no visible documentation elements in this module; the declarative
// macro is documented in the matchers module.
#![doc(hidden)]

/// Matches a container whose elements in any order have a 1:1 correspondence
/// with the provided element matchers.
///
/// ```
/// # use googletest::prelude::*;
/// # fn should_pass() -> Result<()> {
/// verify_that!(vec![3, 2, 1], unordered_elements_are![eq(&1), ge(&2), anything()])?;   // Passes
/// #     Ok(())
/// # }
/// # fn should_fail_1() -> Result<()> {
/// verify_that!(vec![1], unordered_elements_are![eq(&1), ge(&2)])?;              // Fails: container has wrong size
/// #     Ok(())
/// # }
/// # fn should_fail_2() -> Result<()> {
/// verify_that!(vec![3, 2, 1], unordered_elements_are![eq(&1), ge(&4), eq(&2)])?; // Fails: second matcher not matched
/// #     Ok(())
/// # }
/// # fn should_fail_3() -> Result<()> {
/// verify_that!(vec![3, 2, 1], unordered_elements_are![ge(&3), ge(&3), ge(&3)])?; // Fails: no 1:1 correspondence
/// #     Ok(())
/// # }
/// # should_pass().unwrap();
/// # should_fail_1().unwrap_err();
/// # should_fail_2().unwrap_err();
/// # should_fail_3().unwrap_err();
/// ```
///
/// The actual value must be a container such as a `&Vec`, an array, or a
/// slice. More precisely, the actual value must implement [`IntoIterator`].
///
/// This can also be omitted in [`verify_that!`] macros and replaced with curly
/// brackets.
///
/// ```
/// # use googletest::prelude::*;
///  verify_that!(vec![1, 2], {eq(&2), eq(&1)})
/// #     .unwrap();
/// ```
///
/// Note: This behavior is only possible in [`verify_that!`] macros. In any
/// other cases, it is still necessary to use the
/// [`unordered_elements_are!`][crate::matchers::unordered_elements_are] macro.
///
/// ```compile_fail
/// # use googletest::prelude::*;
/// verify_that!(vec![vec![1,2], vec![3]], {{eq(2), eq(1)}, {eq(3)}})
/// # .unwrap();
/// ```
///
/// Use this instead:
/// ```
/// # use googletest::prelude::*;
/// verify_that!(vec![vec![1,2], vec![3]],
///   {unordered_elements_are![eq(&2), eq(&1)], unordered_elements_are![eq(&3)]})
/// # .unwrap();
/// ```
///
///  If an inner matcher is `eq(...)`, it can be omitted:
///
/// ```
/// # use googletest::prelude::*;
///
/// verify_that!(vec![1,2,3], unordered_elements_are![lt(&2), gt(&1), &3])
/// #     .unwrap();
/// ```
///
/// The matcher proceeds in three stages:
///
/// 1. It first checks whether the actual value is of the right size to possibly
///    be matched by each of the given matchers. If not, then it immediately
///    fails explaining that the size is incorrect.
///
/// 2. It then checks whether each matcher matches at least one corresponding
///    element in the actual container and each element in the actual container
///    is matched by at least one matcher. If not, it fails with a message
///    indicating which matcher respectively container elements had no
///    counterparts.
///
/// 3. Finally, it checks whether the mapping of matchers to corresponding
///    actual elements is a 1-1 correspondence and fails if that is not the
///    case. The failure message then shows the best matching it could find,
///    including which matchers did not have corresponding unique elements in
///    the container and which container elements had no corresponding matchers.
///
/// [`IntoIterator`]: std::iter::IntoIterator
/// [`Iterator`]: std::iter::Iterator
/// [`Iterator::collect`]: std::iter::Iterator::collect
/// [`Vec`]: std::vec::Vec
#[macro_export]
#[doc(hidden)]
macro_rules! __unordered_elements_are {
    ($(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [],
            $crate::matchers::__internal_unstable_do_not_depend_on_these::
            Requirements::PerfectMatch)
    }};

    ($($matcher:expr),* $(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [$(Box::new(
                $crate::matcher_support::__internal_unstable_do_not_depend_on_these::auto_eq!(
                    $matcher
                )
            )),*],
            $crate::matchers::__internal_unstable_do_not_depend_on_these::
            Requirements::PerfectMatch)
    }};
}

/// Matches a container containing elements matched by the given matchers.
///
/// To match, each given matcher must have a corresponding element in the
/// container which it matches. There must be a mapping uniquely matching each
/// matcher to a container element. The container can, however, contain
/// additional elements that don't correspond to any matcher.
///
/// Put another way, `contains_each!` matches if there is a subset of the actual
/// container which
/// [`unordered_elements_are`][crate::matchers::unordered_elements_are] would
/// match.
///
/// ```
/// # use googletest::prelude::*;
/// # fn should_pass() -> Result<()> {
/// verify_that!(vec![3, 2, 1], contains_each![eq(&2), ge(&3)])?;   // Passes
/// verify_that!(vec![3, 2, 1], contains_each![ge(&2), ge(&2)])?;   // Passes
/// #     Ok(())
/// # }
/// # fn should_fail_1() -> Result<()> {
/// verify_that!(vec![1], contains_each![eq(&1), ge(&2)])?;         // Fails: container too small
/// #     Ok(())
/// # }
/// # fn should_fail_2() -> Result<()> {
/// verify_that!(vec![3, 2, 1], contains_each![eq(&1), ge(&4)])?;   // Fails: second matcher unmatched
/// #     Ok(())
/// # }
/// # fn should_fail_3() -> Result<()> {
/// verify_that!(vec![3, 2, 1], contains_each![ge(&3), ge(&3), ge(&3)])?; // Fails: no matching
/// #     Ok(())
/// # }
/// # should_pass().unwrap();
/// # should_fail_1().unwrap_err();
/// # should_fail_2().unwrap_err();
/// # should_fail_3().unwrap_err();
/// ```
///
/// The actual value must be a container such as a `&Vec`, an array, or a
/// slice. More precisely, the actual value must implement [`IntoIterator`].
///
///  If an inner matcher is `eq(...)`, it can be omitted:
///
/// ```
/// # use googletest::prelude::*;
///
/// verify_that!(vec![1,2,3], contains_each![lt(&2), &3])
/// #     .unwrap();
/// ```
///
/// The matcher proceeds in three stages:
///
/// 1. It first checks whether the actual value is large enough to possibly be
///    matched by each of the given matchers. If not, then it immediately fails
///    explaining that the size is too small.
///
/// 2. It then checks whether each matcher matches at least one corresponding
///    element in the actual container and fails if that is not the case. The
///    failure message indicates which matcher had no corresponding element.
///
/// 3. Finally, it checks whether the mapping of matchers to corresponding
///    actual elements is 1-1 and fails if that is not the case. The failure
///    message then shows the best matching it could find, including which
///    matchers did not have corresponding unique elements in the container.
///
/// [`IntoIterator`]: std::iter::IntoIterator
/// [`Iterator`]: std::iter::Iterator
/// [`Iterator::collect`]: std::iter::Iterator::collect
/// [`Vec`]: std::vec::Vec
#[macro_export]
#[doc(hidden)]
macro_rules! __contains_each {
    ($(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [],
            $crate::matchers::__internal_unstable_do_not_depend_on_these::Requirements::Superset)
    }};

    ($($matcher:expr),* $(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [$(Box::new(
                $crate::matcher_support::__internal_unstable_do_not_depend_on_these::auto_eq!(
                    $matcher
                )
            )),*],
            $crate::matchers::__internal_unstable_do_not_depend_on_these::Requirements::Superset)
    }}
}

/// Matches a container all of whose elements are matched by the given matchers.
///
/// To match, each element in the container must have a corresponding matcher
/// which matches it. There must be a 1-1 mapping from container elements to
/// matchers, so that no matcher has more than one corresponding element.
///
/// There may, however, be matchers not corresponding to any elements in the
/// container.
///
/// Put another way, `is_contained_in!` matches if there is a subset of the
/// matchers which would match with
/// [`unordered_elements_are`][crate::matchers::unordered_elements_are].
///
/// ```
/// # use googletest::prelude::*;
/// # fn should_pass() -> Result<()> {
/// verify_that!(vec![2, 1], is_contained_in![eq(&1), ge(&2)])?;   // Passes
/// verify_that!(vec![2, 1], is_contained_in![ge(&1), ge(&1)])?;   // Passes
/// #     Ok(())
/// # }
/// # fn should_fail_1() -> Result<()> {
/// verify_that!(vec![1, 2, 3], is_contained_in![eq(&1), ge(&2)])?; // Fails: container too large
/// #     Ok(())
/// # }
/// # fn should_fail_2() -> Result<()> {
/// verify_that!(vec![2, 1], is_contained_in![eq(&1), ge(&4)])?;    // Fails: second matcher unmatched
/// #     Ok(())
/// # }
/// # fn should_fail_3() -> Result<()> {
/// verify_that!(vec![3, 1], is_contained_in![ge(&3), ge(&3), ge(&3)])?; // Fails: no matching
/// #     Ok(())
/// # }
/// # should_pass().unwrap();
/// # should_fail_1().unwrap_err();
/// # should_fail_2().unwrap_err();
/// # should_fail_3().unwrap_err();
/// ```
///
/// The actual value must be a container such as a `&Vec`, an array, or a slice.
/// More precisely, the actual value must implement [`IntoIterator`].
///
///  If an inner matcher is `eq(...)`, it can be omitted:
///
/// ```
/// # use googletest::prelude::*;
///
/// verify_that!(vec![1,2,3], is_contained_in![lt(&2), &3, &4, gt(&0)])
/// #     .unwrap();
/// ```
///
/// The matcher proceeds in three stages:
///
/// 1. It first checks whether the actual value is too large to possibly be
///    matched by each of the given matchers. If so, it immediately fails
///    explaining that the size is too large.
///
/// 2. It then checks whether each actual container element is matched by at
///    least one matcher and fails if that is not the case. The failure message
///    indicates which element had no corresponding matcher.
///
/// 3. Finally, it checks whether the mapping of elements to corresponding
///    matchers is 1-1 and fails if that is not the case. The failure message
///    then shows the best matching it could find, including which container
///    elements did not have corresponding matchers.
///
/// [`IntoIterator`]: std::iter::IntoIterator
/// [`Iterator`]: std::iter::Iterator
/// [`Iterator::collect`]: std::iter::Iterator::collect
/// [`Vec`]: std::vec::Vec
#[macro_export]
#[doc(hidden)]
macro_rules! __is_contained_in {
    ($(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [], $crate::matchers::__internal_unstable_do_not_depend_on_these::Requirements::Subset)
    }};

    ($($matcher:expr),* $(,)?) => {{
        $crate::matchers::__internal_unstable_do_not_depend_on_these::
        UnorderedElementsAreMatcher::new(
            [$(Box::new(
                $crate::matcher_support::__internal_unstable_do_not_depend_on_these::auto_eq!(
                    $matcher
                )
            )),*],
            $crate::matchers::__internal_unstable_do_not_depend_on_these::Requirements::Subset)
    }}
}

/// Module for use only by the macros in this module.
///
/// **For internal use only. API stablility is not guaranteed!**
#[doc(hidden)]
pub mod internal {
    use crate::description::Description;
    use crate::matcher::{Matcher, MatcherBase, MatcherResult};
    use crate::matcher_support::match_matrix::internal::{MatchMatrix, Requirements};
    use std::fmt::Debug;

    /// This struct is meant to be used only through the
    /// `unordered_elements_are![...]` macro.
    ///
    /// **For internal use only. API stablility is not guaranteed!**
    #[doc(hidden)]
    #[derive(MatcherBase)]
    pub struct UnorderedElementsAreMatcher<'a, T: Debug + Copy, const N: usize> {
        elements: [Box<dyn Matcher<T> + 'a>; N],
        requirements: Requirements,
    }

    impl<'a, T: Debug + Copy, const N: usize> UnorderedElementsAreMatcher<'a, T, N> {
        pub fn new(elements: [Box<dyn Matcher<T> + 'a>; N], requirements: Requirements) -> Self {
            Self { elements, requirements }
        }
    }

    // This matcher performs the checks in three different steps in both `matches`
    // and `explain_match`. This is useful for performance but also to produce
    // an actionable error message.
    // 1. `UnorderedElementsAreMatcher` verifies that both collections have the same
    // size
    // 2. `UnorderedElementsAreMatcher` verifies that each actual element matches at
    // least one expected element and vice versa.
    // 3. `UnorderedElementsAreMatcher` verifies that a perfect matching exists
    // using Ford-Fulkerson.
    impl<T: Debug + Copy, ContainerT: Debug + Copy, const N: usize> Matcher<ContainerT>
        for UnorderedElementsAreMatcher<'_, T, N>
    where
        ContainerT: IntoIterator<Item = T>,
    {
        fn matches(&self, actual: ContainerT) -> MatcherResult {
            let match_matrix = MatchMatrix::generate(actual, &self.elements);
            match_matrix.is_match_for(self.requirements).into()
        }

        fn explain_match(&self, actual: ContainerT) -> Description {
            if let Some(size_mismatch_explanation) =
                self.requirements.explain_size_mismatch(actual, N)
            {
                return size_mismatch_explanation;
            }

            let match_matrix = MatchMatrix::generate(actual, &self.elements);
            if let Some(unmatchable_explanation) =
                match_matrix.explain_unmatchable(self.requirements)
            {
                return unmatchable_explanation;
            }

            let best_match = match_matrix.find_best_match();
            best_match
                .get_explanation(actual, &self.elements, self.requirements)
                .unwrap_or("whose elements all match".into())
        }

        fn describe(&self, matcher_result: MatcherResult) -> Description {
            format!(
                "{} elements matching in any order:\n{}",
                if matcher_result.into() { "contains" } else { "doesn't contain" },
                self.elements
                    .iter()
                    .map(|matcher| matcher.describe(MatcherResult::Match))
                    .collect::<Description>()
                    .enumerate()
                    .indent()
            )
            .into()
        }
    }
}

#[cfg(test)]
mod tests {
    use crate as googletest;
    use crate::matcher::MatcherResult;
    use crate::prelude::*;
    use indoc::indoc;
    use std::collections::HashMap;

    #[test]
    fn has_correct_description_for_map() -> googletest::Result<()> {
        // UnorderedElementsAreMatcher maintains references to the matchers, so the
        // constituent matchers must live longer. Inside a verify_that! macro, the
        // compiler takes care of that, but when the matcher is created separately,
        // we must create the constitute matchers separately so that they
        // aren't dropped too early.
        let matchers = ((eq(&2), eq(&"Two")), (eq(&1), eq(&"One")), (eq(&3), eq(&"Three")));
        let matcher = unordered_elements_are![
            (matchers.0 .0, matchers.0 .1),
            (matchers.1 .0, matchers.1 .1),
            (matchers.2 .0, matchers.2 .1)
        ];
        verify_that!(
            Matcher::<&HashMap<i32, String>>::describe(&matcher, MatcherResult::Match),
            displays_as(eq(indoc!(
                "
                contains elements matching in any order:
                  0. is a tuple whose values respectively match:
                       is equal to 2
                       is equal to \"Two\"
                  1. is a tuple whose values respectively match:
                       is equal to 1
                       is equal to \"One\"
                  2. is a tuple whose values respectively match:
                       is equal to 3
                       is equal to \"Three\""
            )))
        )
    }

    #[test]
    fn unordered_elements_are_description_no_full_match_with_map() -> googletest::Result<()> {
        // UnorderedElementsAreMatcher maintains references to the matchers, so the
        // constituent matchers must live longer. Inside a verify_that! macro, the
        // compiler takes care of that, but when the matcher is created separately,
        // we must create the constitute matchers separately so that they
        // aren't dropped too early.
        let value: HashMap<u32, u32> = HashMap::from_iter([(0, 1), (1, 1), (2, 2)]);
        let matchers = ((anything(), eq(&1)), (anything(), eq(&2)), (anything(), eq(&2)));
        let matcher = unordered_elements_are![
            (matchers.0 .0, matchers.0 .1),
            (matchers.1 .0, matchers.1 .1),
            (matchers.2 .0, matchers.2 .1),
        ];
        verify_that!(
            matcher.explain_match(&value),
            all![
                displays_as(contains_regex(
                    "Actual element \\(2, 2\\) at index [0-2] matched expected element `is a tuple whose values respectively match:\n    is anything\n    is equal to 2` at index [0-2]."
                )),
                displays_as(contains_regex(
                    "Actual element \\(\n      [0-1],\n      [0-1],\n  \\) at index [0-2] did not match any remaining expected element."
                )),
                displays_as(contains_substring(
                    "Expected element `is a tuple whose values respectively match:\n    is anything\n    is equal to 2` at index 2 did not match any remaining actual element."
                ))
            ]
        )
    }
}