Merge pull request #3112 from Ad115/Ad115

Added emphasis to the error source

news/prompt_error.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* Errors while formatting the prompt are highlighted for easier debugging.
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

tests/test_prompt.py

@@ -94,7 +94,7 @@ def test_format_prompt_with_invalid_func(formatter, xonsh_builtins):
 def test_format_prompt_with_func_that_raises(formatter, capsys, xonsh_builtins):
     xonsh_builtins.__xonsh__.env = Env()
     template = "tt {zerodiv} tt"
-    exp = "tt (ERROR:zerodiv) tt"
+    exp = "tt {BACKGROUND_RED}{ERROR:zerodiv}{NO_COLOR} tt"
     fields = {"zerodiv": lambda: 1 / 0}
     obs = formatter(template, fields)
     assert exp == obs

xonsh/prompt/base.py

@@ -83,7 +83,7 @@ class PromptFormatter:
         except Exception:
             print("prompt: error: on field {!r}" "".format(field), file=sys.stderr)
             xt.print_exception()
-            value = "(ERROR:{})".format(field)
+            value = "{{BACKGROUND_RED}}{{ERROR:{}}}{{NO_COLOR}}".format(field)
         return value