decode_datetime(): Return a `Result`

Make a custom error type because it's trickier to integrate with
'error-chain' given that 'magic-crypt''s `Error` type doesn't implement
the `std::error::Error` trait.

For the same reason, we can't use that as the `cause` for
`DateCryptError::Decrypt`.

This allows us to capture the errors without panicking.

Include some additional cleanups as a result of removing the `use
std::result` and `use errors::*` imports.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/errors.rs b/src/errors.rs
index 5f09c27..c2048e9 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -1,3 +1,5 @@
+use chrono;
+use magic_crypt;
 use xdg;
 
 error_chain! {
@@ -15,3 +17,18 @@ quick_error! {
         }
     }
 }
+
+quick_error! {
+    #[derive(Debug)]
+    pub enum DateCryptError {
+        DateParse(err: chrono::format::ParseError) {
+            from()
+            cause(err)
+            display("unable to parse timestamp")
+        }
+        Decrypt(err: magic_crypt::Error) {
+            from()
+            display("unable to read trial key")
+        }
+    }
+}