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
9 use std::fmt;
10 use std::path;
11
12 use crate::reflection;
13 use crate::utils;
14 use 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)]
20 pub struct ExistencePredicate {
21 exists: bool,
22 }
23
24 impl Predicate<path::Path> for ExistencePredicate {
eval(&self, path: &path::Path) -> bool25 fn eval(&self, path: &path::Path) -> bool {
26 path.exists() == self.exists
27 }
28
find_case<'a>( &'a self, expected: bool, variable: &path::Path, ) -> Option<reflection::Case<'a>>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
43 impl reflection::PredicateReflection for ExistencePredicate {}
44
45 impl fmt::Display for ExistencePredicate {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result46 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
47 let palette = crate::Palette::new(f.alternate());
48 write!(
49 f,
50 "{}({})",
51 palette.description(if self.exists { "exists" } else { "missing" }),
52 palette.var("var")
53 )
54 }
55 }
56
57 /// Creates a new `Predicate` that ensures the path exists.
58 ///
59 /// # Examples
60 ///
61 /// ```
62 /// use std::path::Path;
63 /// use predicates::prelude::*;
64 ///
65 /// let predicate_fn = predicate::path::exists();
66 /// assert_eq!(true, predicate_fn.eval(Path::new("Cargo.toml")));
67 /// ```
exists() -> ExistencePredicate68 pub fn exists() -> ExistencePredicate {
69 ExistencePredicate { exists: true }
70 }
71
72 /// Creates a new `Predicate` that ensures the path doesn't exist.
73 ///
74 /// # Examples
75 ///
76 /// ```
77 /// use std::path::Path;
78 /// use predicates::prelude::*;
79 ///
80 /// let predicate_fn = predicate::path::missing();
81 /// assert_eq!(true, predicate_fn.eval(Path::new("non-existent-file.foo")));
82 /// ```
missing() -> ExistencePredicate83 pub fn missing() -> ExistencePredicate {
84 ExistencePredicate { exists: false }
85 }
86