patches/0001-Support-RUST_BACKTRACE-settings-in-test_fmt.patch

From 7a58c3792b5f844514036b1f098eda228ba0ab8f Mon Sep 17 00:00:00 2001
From: Matthew Maurer <mmaurer@google.com>
Date: Tue, 23 Nov 2021 22:39:07 +0000
Subject: [PATCH] Support RUST_BACKTRACE settings in test_fmt

Setting `RUST_BACKTRACE` when running tests is useful so that the logs
will contain backtraces when a test fails. `anyhow` uses this
environment variable as well when formatting its errors. `test_fmt`
currently tests that formatting is an exact match, so adding a trailing
backtrace causes them to fail.

This patch checks that the formatted error *starts with* the intended
result, thus allowing it to pass when a backtrace is appended.

Change-Id: I7ea8bcded841558d845f0cba4a92a2339a6db3f5
---
 tests/test_fmt.rs | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tests/test_fmt.rs b/tests/test_fmt.rs
index cc49291..5703ebb 100644
--- a/tests/test_fmt.rs
+++ b/tests/test_fmt.rs
@@ -68,27 +68,27 @@ Error {
 
 #[test]
 fn test_display() {
-    assert_eq!("g failed", h().unwrap_err().to_string());
+    assert!(h().unwrap_err().to_string().starts_with("g failed"));
 }
 
 #[test]
 fn test_altdisplay() {
-    assert_eq!(EXPECTED_ALTDISPLAY_F, format!("{:#}", f().unwrap_err()));
-    assert_eq!(EXPECTED_ALTDISPLAY_G, format!("{:#}", g().unwrap_err()));
-    assert_eq!(EXPECTED_ALTDISPLAY_H, format!("{:#}", h().unwrap_err()));
+    assert!(format!("{:#}", f().unwrap_err()).starts_with(EXPECTED_ALTDISPLAY_F));
+    assert!(format!("{:#}", g().unwrap_err()).starts_with(EXPECTED_ALTDISPLAY_G));
+    assert!(format!("{:#}", h().unwrap_err()).starts_with(EXPECTED_ALTDISPLAY_H));
 }
 
 #[test]
 #[cfg_attr(not(backtrace), ignore)]
 fn test_debug() {
-    assert_eq!(EXPECTED_DEBUG_F, format!("{:?}", f().unwrap_err()));
-    assert_eq!(EXPECTED_DEBUG_G, format!("{:?}", g().unwrap_err()));
-    assert_eq!(EXPECTED_DEBUG_H, format!("{:?}", h().unwrap_err()));
+    assert!(format!("{:?}", f().unwrap_err()).starts_with(EXPECTED_DEBUG_F));
+    assert!(format!("{:?}", g().unwrap_err()).starts_with(EXPECTED_DEBUG_G));
+    assert!(format!("{:?}", h().unwrap_err()).starts_with(EXPECTED_DEBUG_H));
 }
 
 #[test]
 fn test_altdebug() {
-    assert_eq!(EXPECTED_ALTDEBUG_F, format!("{:#?}", f().unwrap_err()));
-    assert_eq!(EXPECTED_ALTDEBUG_G, format!("{:#?}", g().unwrap_err()));
-    assert_eq!(EXPECTED_ALTDEBUG_H, format!("{:#?}", h().unwrap_err()));
+    assert!(format!("{:#?}", f().unwrap_err()).starts_with(EXPECTED_ALTDEBUG_F));
+    assert!(format!("{:#?}", g().unwrap_err()).starts_with(EXPECTED_ALTDEBUG_G));
+    assert!(format!("{:#?}", h().unwrap_err()).starts_with(EXPECTED_ALTDEBUG_H));
 }
-- 
2.34.0.rc2.393.gf8c9666880-goog