expectest 0.12.0

use crate::core::{Join, Matcher};
use std::fmt;

/// A matcher for `be_some` assertions for `Option<T>` types.
pub struct BeSome;

/// Returns a new `BeSome` matcher.
pub fn be_some() -> BeSome {
    BeSome
}

impl BeSome {
    /// Returns a new `BeSomeValue` matcher.
    pub fn value<E>(self, v: E) -> BeSomeValue<E> {
        BeSomeValue { value: v }
    }
}

impl<A> Matcher<Option<A>, ()> for BeSome
where
    A: fmt::Debug,
{
    fn failure_message(&self, join: Join, actual: &Option<A>) -> String {
        format!("expected {} be Some, got <{:?}>", join, actual)
    }

    fn matches(&self, actual: &Option<A>) -> bool {
        actual.is_some()
    }
}

/// A matcher for `be_some` assertions with value for `Option<T>` types.
pub struct BeSomeValue<E> {
    value: E,
}

impl<A, E> Matcher<Option<A>, E> for BeSomeValue<E>
where
    A: PartialEq<E> + fmt::Debug,
    E: fmt::Debug,
{
    fn failure_message(&self, join: Join, actual: &Option<A>) -> String {
        format!(
            "expected {} be equal to <Some({:?})>, got <{:?}>",
            join, self.value, actual
        )
    }

    fn matches(&self, actual: &Option<A>) -> bool {
        if let Some(a) = actual.as_ref() {
            a == &self.value
        } else {
            false
        }
    }
}

/// A matcher for `be_none` assertions for `Option<T>` types.
pub struct BeNone;

/// Returns a new `BeNone` matcher.
pub fn be_none() -> BeNone {
    BeNone
}

impl<A> Matcher<Option<A>, ()> for BeNone
where
    A: fmt::Debug,
{
    fn failure_message(&self, join: Join, actual: &Option<A>) -> String {
        format!("expected {} be None, got <{:?}>", join, actual)
    }

    fn matches(&self, actual: &Option<A>) -> bool {
        actual.is_none()
    }
}

#[cfg(test)]
mod tests {
    use super::{be_none, be_some};
    use crate::core::expect;

    #[test]
    fn be_some_failure_message() {
        expect(None::<u8>)
            .to(be_some())
            .assert_eq_message("expected to be Some, got <None>");
    }

    #[test]
    fn be_some_value_failure_message_1() {
        expect(None::<u8>)
            .to(be_some().value(1))
            .assert_eq_message("expected to be equal to <Some(1)>, got <None>");
    }

    #[test]
    fn be_some_value_failure_message_2() {
        expect(Some(2))
            .to(be_some().value(1))
            .assert_eq_message("expected to be equal to <Some(1)>, got <Some(2)>");
    }

    #[test]
    fn be_none_failure_message() {
        expect(Some(2))
            .to(be_none())
            .assert_eq_message("expected to be None, got <Some(2)>");
    }
}