1 files changed, 92 insertions, 0 deletions
diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..c75fe4c
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,92 @@
+#[cfg(feature = "failure")]
+use failure::{Backtrace, Context, Fail};
+use std;
+use std::fmt::{self, Display};
+
+#[derive(Debug)]
+pub struct Error {
+    #[cfg(feature = "failure")]
+    inner: Context<ErrorKind>,
+    #[cfg(not(feature = "failure"))]
+    inner: ErrorKind,
+}
+
+// To suppress false positives from cargo-clippy
+#[cfg_attr(feature = "cargo-clippy", allow(empty_line_after_outer_attr))]
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+pub enum ErrorKind {
+    BadAbsolutePath,
+    BadRelativePath,
+    CannotFindBinaryPath,
+    CannotGetCurrentDir,
+    CannotCanonicalize,
+}
+
+#[cfg(feature = "failure")]
+impl Fail for ErrorKind {}
+
+impl Display for ErrorKind {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let display = match *self {
+            ErrorKind::BadAbsolutePath => "Bad absolute path",
+            ErrorKind::BadRelativePath => "Bad relative path",
+            ErrorKind::CannotFindBinaryPath => "Cannot find binary path",
+            ErrorKind::CannotGetCurrentDir => "Cannot get current directory",
+            ErrorKind::CannotCanonicalize => "Cannot canonicalize path",
+        };
+        f.write_str(display)
+    }
+}
+
+#[cfg(feature = "failure")]
+impl Fail for Error {
+    fn cause(&self) -> Option<&dyn Fail> {
+        self.inner.cause()
+    }
+
+    fn backtrace(&self) -> Option<&Backtrace> {
+        self.inner.backtrace()
+    }
+}
+
+#[cfg(not(feature = "failure"))]
+impl std::error::Error for Error {}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.inner, f)
+    }
+}
+
+impl Error {
+    pub fn kind(&self) -> ErrorKind {
+        #[cfg(feature = "failure")]
+        {
+            *self.inner.get_context()
+        }
+        #[cfg(not(feature = "failure"))]
+        {
+            self.inner
+        }
+    }
+}
+
+impl From<ErrorKind> for Error {
+    fn from(kind: ErrorKind) -> Error {
+        Error {
+            #[cfg(feature = "failure")]
+            inner: Context::new(kind),
+            #[cfg(not(feature = "failure"))]
+            inner: kind,
+        }
+    }
+}
+
+#[cfg(feature = "failure")]
+impl From<Context<ErrorKind>> for Error {
+    fn from(inner: Context<ErrorKind>) -> Error {
+        Error { inner }
+    }
+}
+
+pub type Result<T> = std::result::Result<T, Error>;