fixup! fixup! fixup! fixup! fixup! fixup! Add syntactic highlighting to the error explanations

src/_pytest/_io/terminalwriter.py

@@ -223,12 +223,14 @@ class TerminalWriter:
                         style=os.getenv("PYTEST_THEME"),
                     ),
                 )
+                # pygments terminal formatter may add a newline when there wasn't one.
+                # We don't want this, remove.
                 if highlighted[-1] == "\n" and source[-1] != "\n":
                     highlighted = highlighted[:-1]
 
                 # Some lexers will not set the initial color explicitly
                 # which may lead to the previous color being propagated to the
-                # start of the expression
+                # start of the expression, so reset first.
                 return "\x1b[0m" + highlighted
             except pygments.util.ClassNotFound:
                 raise UsageError(

src/_pytest/assertion/util.py

@@ -513,7 +513,6 @@ def _compare_eq_dict(
         )
         explanation.extend(
             highlighter(pprint.pformat({k: left[k] for k in extra_left}))
-            .strip()
             .splitlines()
         )
     extra_right = set_right - set_left
@@ -525,7 +524,6 @@ def _compare_eq_dict(
         )
         explanation.extend(
             highlighter(pprint.pformat({k: right[k] for k in extra_right}))
-            .strip()
             .splitlines()
         )
     return explanation