1// Copyright (c) 2018 The predicates-rs Project Developers.
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9use std::fmt;
10use std::path;
11
12use crate::reflection;
13use crate::utils;
14use crate::Predicate;
15
16/// Predicate that checks if a file is present
17///
18/// This is created by the `predicate::path::exists` and `predicate::path::missing`.
19#[derive(Debug, Clone, Copy, PartialEq, Eq)]
20pub struct ExistencePredicate {
21 exists: bool,
22}
23
24impl Predicate<path::Path> for ExistencePredicate {
25 fn eval(&self, path: &path::Path) -> bool {
26 path.exists() == self.exists
27 }
28
29 fn find_case<'a>(
30 &'a self,
31 expected: bool,
32 variable: &path::Path,
33 ) -> Option<reflection::Case<'a>> {
34 utils::default_find_case(self, expected, variable).map(|case| {
35 case.add_product(reflection::Product::new(
36 "var",
37 variable.display().to_string(),
38 ))
39 })
40 }
41}
42
43impl reflection::PredicateReflection for ExistencePredicate {}
44
45impl fmt::Display for ExistencePredicate {
46 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
47 let palette = crate::Palette::current();
48 write!(
49 f,
50 "{}({})",
51 palette
52 .description
53 .paint(if self.exists { "exists" } else { "missing" }),
54 palette.var.paint("var")
55 )
56 }
57}
58
59/// Creates a new `Predicate` that ensures the path exists.
60///
61/// # Examples
62///
63/// ```
64/// use std::path::Path;
65/// use predicates::prelude::*;
66///
67/// let predicate_fn = predicate::path::exists();
68/// assert_eq!(true, predicate_fn.eval(Path::new("Cargo.toml")));
69/// ```
70pub fn exists() -> ExistencePredicate {
71 ExistencePredicate { exists: true }
72}
73
74/// Creates a new `Predicate` that ensures the path doesn't exist.
75///
76/// # Examples
77///
78/// ```
79/// use std::path::Path;
80/// use predicates::prelude::*;
81///
82/// let predicate_fn = predicate::path::missing();
83/// assert_eq!(true, predicate_fn.eval(Path::new("non-existent-file.foo")));
84/// ```
85pub fn missing() -> ExistencePredicate {
86 ExistencePredicate { exists: false }
87}
88