flashrom_tester: Refactor Error type

Use a type implementing Error instead of a string for errors. Error
implements Display so can be easily converted to a String. This will
allow libflashrom to be more easily integrated.

BUG=b:230545739
BRANCH=None
TEST=cargo test

Change-Id: Id166053c7edfd07576e7823692cfa0ea4d438948
Signed-off-by: Evan Benn <evanbenn@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/65277
Reviewed-by: Peter Marheine <pmarheine@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/util/flashrom_tester/flashrom/src/lib.rs b/util/flashrom_tester/flashrom/src/lib.rs
index fff5863bc..e01acbb9b 100644
--- a/util/flashrom_tester/flashrom/src/lib.rs
+++ b/util/flashrom_tester/flashrom/src/lib.rs
@@ -38,6 +38,8 @@ extern crate log;
 
 mod cmd;
 
+use std::{error, fmt};
+
 pub use cmd::{dut_ctrl_toggle_wp, FlashromCmd};
 
 #[derive(Copy, Clone, PartialEq, Debug)]
@@ -81,7 +83,27 @@ impl FlashChip {
     }
 }
 
-pub type FlashromError = String;
+#[derive(Debug, PartialEq)]
+pub struct FlashromError {
+    msg: String,
+}
+
+impl fmt::Display for FlashromError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.msg)
+    }
+}
+
+impl error::Error for FlashromError {}
+
+impl<T> From<T> for FlashromError
+where
+    T: Into<String>,
+{
+    fn from(msg: T) -> Self {
+        FlashromError { msg: msg.into() }
+    }
+}
 
 pub struct ROMWriteSpecifics<'a> {
     pub layout_file: Option<&'a str>,