1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87

// Copyright (c) 2018 The predicates-rs Project Developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::fmt;
use std::path;

use crate::reflection;
use crate::utils;
use crate::Predicate;

/// Predicate that checks if a file is present
///
/// This is created by the `predicate::path::exists` and `predicate::path::missing`.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct ExistencePredicate {
    exists: bool,
}

impl Predicate<path::Path> for ExistencePredicate {
    fn eval(&self, path: &path::Path) -> bool {
        path.exists() == self.exists
    }

    fn find_case<'a>(
        &'a self,
        expected: bool,
        variable: &path::Path,
    ) -> Option<reflection::Case<'a>> {
        utils::default_find_case(self, expected, variable).map(|case| {
            case.add_product(reflection::Product::new(
                "var",
                variable.display().to_string(),
            ))
        })
    }
}

impl reflection::PredicateReflection for ExistencePredicate {}

impl fmt::Display for ExistencePredicate {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let palette = crate::Palette::current();
        write!(
            f,
            "{}({})",
            palette
                .description
                .paint(if self.exists { "exists" } else { "missing" }),
            palette.var.paint("var")
        )
    }
}

/// Creates a new `Predicate` that ensures the path exists.
///
/// # Examples
///
/// ```
/// use std::path::Path;
/// use predicates::prelude::*;
///
/// let predicate_fn = predicate::path::exists();
/// assert_eq!(true, predicate_fn.eval(Path::new("Cargo.toml")));
/// ```
pub fn exists() -> ExistencePredicate {
    ExistencePredicate { exists: true }
}

/// Creates a new `Predicate` that ensures the path doesn't exist.
///
/// # Examples
///
/// ```
/// use std::path::Path;
/// use predicates::prelude::*;
///
/// let predicate_fn = predicate::path::missing();
/// assert_eq!(true, predicate_fn.eval(Path::new("non-existent-file.foo")));
/// ```
pub fn missing() -> ExistencePredicate {
    ExistencePredicate { exists: false }
}