Merge pull request #20941 from zeertzjq/vim-8.2.1183

vim-patch:8.2.{partial:1183,1184,1199,1479,1484,1631,1632}: assert_fails() patches

1 files changed, 33 insertions, 5 deletions

diff --git a/runtime/doc/testing.txt b/runtime/doc/testing.txt
index f4375c3363..56e0dad656 100644
--- a/runtime/doc/testing.txt
+++ b/runtime/doc/testing.txt
@@ -98,18 +98,46 @@ assert_exception({error} [, {msg}])			*assert_exception()*
 			catch
 			  call assert_exception('E492:')
 			endtry
-
-assert_fails({cmd} [, {error} [, {msg}]])			*assert_fails()*
+<
+							*assert_fails()*
+assert_fails({cmd} [, {error} [, {msg} [, {lnum} [, {context}]]]])
 		Run {cmd} and add an error message to |v:errors| if it does
-		NOT produce an error.  Also see |assert-return|.
-		When {error} is given it must match in |v:errmsg|.
+		NOT produce an error or when {error} is not found in the
+		error message.  Also see |assert-return|.
+
+		When {error} is a string it must be found literally in the
+		first reported error. Most often this will be the error code,
+		including the colon, e.g. "E123:". >
+			assert_fails('bad cmd', 'E987:')
+<
+		When {error} is a |List| with one or two strings, these are
+		used as patterns.  The first pattern is matched against the
+		first reported error: >
+			assert_fails('cmd', ['E987:.*expected bool'])
+<		The second pattern, if present, is matched against the last
+		reported error.  To only match the last error use an empty
+		string for the first error: >
+			assert_fails('cmd', ['', 'E987:'])
+<
+		If {msg} is empty then it is not used.  Do this to get the
+		default message when passing the {lnum} argument.
+
+		When {lnum} is present and not negative, and the {error}
+		argument is present and matches, then this is compared with
+		the line number at which the error was reported. That can be
+		the line number in a function or in a script.
+
+		When {context} is present it is used as a pattern and matched
+		against the context (script name or function name) where
+		{lnum} is located in.
+
 		Note that beeping is not considered an error, and some failing
 		commands only beep.  Use |assert_beeps()| for those.
 
 		Can also be used as a |method|: >
 			GetCmd()->assert_fails('E99:')
 
-assert_false({actual} [, {msg}])				*assert_false()*
+assert_false({actual} [, {msg}])			*assert_false()*
 		When {actual} is not false an error message is added to
 		|v:errors|, like with |assert_equal()|.
 		Also see |assert-return|.