1 files changed, 85 insertions, 0 deletions
diff --git a/src/path/existence.rs b/src/path/existence.rs
new file mode 100644
index 0000000..343a9c1
--- /dev/null
+++ b/src/path/existence.rs
@@ -0,0 +1,85 @@
+// 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::new(f.alternate());
+        write!(
+            f,
+            "{}({})",
+            palette.description(if self.exists { "exists" } else { "missing" }),
+            palette.var("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 }
+}