Vim documentation: testing
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*testing.txt* For Vim version 9.1. Last change: 2023 May 18
VIM REFERENCE MANUAL by Bram Moolenaar
Testing Vim and Vim script *testing-support*
Expression evaluation is explained in |eval.txt|. This file goes into details
about writing tests in Vim script. This can be used for testing Vim itself
and for testing plugins.
1. Testing Vim |testing|
2. Test functions |test-functions-details|
3. Assert functions |assert-functions-details|
==============================================================================
1. Testing Vim *testing*
Vim can be tested after building it, usually with "make test".
The tests are located in the directory "src/testdir".
There are two types of tests added over time:
test20.in oldest, only for tiny builds
test_something.vim new style tests
*new-style-testing*
New tests should be added as new style tests. The test scripts are named
test_<feature>.vim (replace <feature> with the feature under test). These use
functions such as |assert_equal()| to keep the test commands and the expected
result in one place.
*old-style-testing*
These tests are used only for testing Vim without the |+eval| feature.
Find more information in the file src/testdir/README.txt.
==============================================================================
2. Test functions *test-functions-details*
test_alloc_fail({id}, {countdown}, {repeat}) *test_alloc_fail()*
This is for testing: If the memory allocation with {id} is
called, then decrement {countdown}, and when it reaches zero
let memory allocation fail {repeat} times. When {repeat} is
smaller than one it fails one time.
Can also be used as a YXXYmethod|:
GetAllocId()->test_alloc_fail()
test_autochdir() *test_autochdir()*
Set a flag to enable the effect of 'autochdir' before Vim
startup has finished.
test_feedinput({string}) *test_feedinput()*
Characters in {string} are queued for processing as if they
were typed by the user. This uses a low level input buffer.
This function works only when with |+unix| or GUI is running.
Can also be used as a YXXYmethod|:
GetText()->test_feedinput()
test_garbagecollect_now() *test_garbagecollect_now()*
Like garbagecollect(), but executed right away. This must
only be called directly to avoid any structure to exist
internally, and |v:testing| must have been set before calling
any function. *E1142*
This will not work when called from a :def function, because
variables on the stack will be freed.
test_garbagecollect_soon() *test_garbagecollect_soon()*
Set the flag to call the garbagecollector as if in the main
loop. Only to be used in tests.
test_getvalue({name}) *test_getvalue()*
Get the value of an internal variable. These values for
{name} are supported:
need_fileinfo
Can also be used as a YXXYmethod|:
GetName()->test_getvalue()
*test_gui_event()*
test_gui_event({event}, {args})
Generate a GUI {event} with arguments {args} for testing Vim
functionality. This function works only when the GUI is
running.
{event} is a String and the supported values are:
"dropfiles" drop one or more files in a window.
"findrepl" search and replace text.
"mouse" mouse button click event.
"scrollbar" move or drag the scrollbar.
"key" send a low-level keyboard event.
"tabline" select a tab page by mouse click.
"tabmenu" select a tabline menu entry.
{args} is a Dict and contains the arguments for the event.
"dropfiles":
Drop one or more files in a specified window. The supported
items in {args} are:
files: List of file names
row: window row number
col: window column number
modifiers: key modifiers. The supported values are:
0x4 Shift
0x8 Alt
0x10 Ctrl
The files are added to the |argument-list| and the first
file in {files} is edited in the window. See |drag-n-drop|
for more information. This event works only when the
|drop_file| feature is present.
"findrepl":
{only available when the GUI has a find/replace dialog}
Perform a search and replace of text. The supported items
in {args} are:
find_text: string to find.
repl_text: replacement string.
flags: flags controlling the find/replace. Supported
values are:
1 search next string (find dialog)
2 search next string (replace dialog)
3 replace string once
4 replace all matches
8 match whole words only
16 match case
forward: set to 1 for forward search.
"mouse":
Inject either a mouse button click, or a mouse move, event.
The supported items in {args} are:
button: mouse button. The supported values are:
0 left mouse button
1 middle mouse button
2 right mouse button
3 mouse button release
4 scroll wheel down
5 scroll wheel up
6 scroll wheel left
7 scroll wheel right
row: mouse click row number. The first row of the
Vim window is 1 and the last row is 'lines'.
col: mouse click column number. The maximum value
of {col} is 'columns'.
multiclick: set to 1 to inject a multiclick mouse event.
modifiers: key modifiers. The supported values are:
4 shift is pressed
8 alt is pressed
16 ctrl is pressed
move: Optional; if used and TRUE then a mouse move
event can be generated.
Only {args} row: and col: are used and
required; they are interpreted as pixels or
screen cells, depending on "cell".
Only results in an event when 'mousemoveevent'
is set or a popup uses mouse move events.
cell: Optional: when present and TRUE then "move"
uses screen cells instead of pixel positions
"scrollbar":
Set or drag the left, right or horizontal scrollbar. Only
works when the scrollbar actually exists. The supported
items in {args} are:
which: Selects the scrollbar. The supported values
are:
left Left scrollbar of the current window
right Right scrollbar of the current window
hor Horizontal scrollbar
value: Amount to scroll. For the vertical scrollbars
the value can be between 0 to the line-count
of the buffer minus one. For the horizontal
scrollbar the value can be between 1 and the
maximum line length, assuming 'wrap' is not
set.
dragging: 1 to drag the scrollbar and 0 to click in the
scrollbar.
"key":
Send a low-level keyboard event (e.g. key-up or down).
Currently only supported on MS-Windows.
The supported items in {args} are:
event: The supported string values are:
keyup generate a keyup event
keydown generate a keydown event
keycode: Keycode to use for a keyup or a keydown event.
*E1291*
"tabline":
Inject a mouse click event on the tabline to select a
tabpage. The supported items in {args} are:
tabnr: tab page number
"tabmenu":
Inject an event to select a tabline menu entry. The
supported items in {args} are:
tabnr: tab page number
item: tab page menu item number. 1 for the first
menu item, 2 for the second item and so on.
After injecting the GUI events you probably should call
|feedkeys()| to have them processed, e.g.:
call feedkeys("y", 'Lx!')
Returns TRUE if the event is successfully added, FALSE if
there is a failure.
Can also be used as a YXXYmethod|:
GetEvent()->test_gui_event({args})
test_ignore_error({expr}) *test_ignore_error()*
Ignore any error containing {expr}. A normal message is given
instead.
This is only meant to be used in tests, where catching the
error with try/catch cannot be used (because it skips over
following code).
{expr} is used literally, not as a pattern.
When the {expr} is the string "RESET" then the list of ignored
errors is made empty.
Can also be used as a YXXYmethod|:
GetErrorText()->test_ignore_error()
test_mswin_event({event}, {args}) *test_mswin_event()*
Generate a low-level MS-Windows {event} with arguments {args}
for testing Vim functionality. It works for MS-Windows GUI
and for the console.
{event} is a String and the supported values are:
"mouse" mouse event.
"key" keyboard event.
"mouse":
Inject either a mouse button click, or a mouse move, event.
The supported items in {args} are:
button: mouse button. The supported values are:
0 right mouse button
1 middle mouse button
2 left mouse button
3 mouse button release
4 scroll wheel down
5 scroll wheel up
6 scroll wheel left
7 scroll wheel right
row: mouse click row number. The first row of the
Vim window is 1 and the last row is 'lines'.
col: mouse click column number. The maximum value
of {col} is 'columns'.
Note: row and col are always interpreted as
screen cells for the console application.
But, they may be interpreted as pixels
for the GUI, depending on "cell".
multiclick: set to 1 to inject a double-click mouse event.
modifiers: key modifiers. The supported values are:
4 shift is pressed
8 alt is pressed
16 ctrl is pressed
move: Optional; if used and TRUE then a mouse move
event can be generated.
Only {args} row: and col: are used and
required.
Only results in an event when 'mousemoveevent'
is set or a popup uses mouse move events.
cell: Optional for the GUI: when present and TRUE
then "move" uses screen cells instead of pixel
positions. Not used by the console.
"key":
Send a low-level keyboard event (e.g. keyup or keydown).
The supported items in {args} are:
event: The supported string values are:
keyup generate a keyup event
keydown generate a keydown event
keycode: Keycode to use for a keyup or a keydown event.
modifiers: Optional; key modifiers.
The supported values are:
2 shift is pressed
4 ctrl is pressed
8 alt is pressed
Note: These values are different from the
mouse modifiers.
execute: Optional. Similar to |feedkeys()| mode x.
When this is included and set to true
(non-zero) then Vim will process any buffered
unprocessed key events. All other {args}
items are optional when this is set and true.
Returns TRUE if the event is successfully added or executed,
FALSE if there is a failure.
Can also be used as a YXXYmethod|:
GetEvent()->test_mswin_event({args})
test_null_blob() *test_null_blob()*
Return a |Blob| that is null. Only useful for testing.
test_null_channel() *test_null_channel()*
Return a |Channel| that is null. Only useful for testing.
{only available when compiled with the +channel feature}
test_null_dict() *test_null_dict()*
Return a |Dict| that is null. Only useful for testing.
test_null_function() *test_null_function()*
Return a |Funcref| that is null. Only useful for testing.
test_null_job() *test_null_job()*
Return a |Job| that is null. Only useful for testing.
{only available when compiled with the +job feature}
test_null_list() *test_null_list()*
Return a |List| that is null. Only useful for testing.
test_null_partial() *test_null_partial()*
Return a |Partial| that is null. Only useful for testing.
test_null_string() *test_null_string()*
Return a |String| that is null. Only useful for testing.
test_option_not_set({name}) *test_option_not_set()*
Reset the flag that indicates option {name} was set. Thus it
looks like it still has the default value. Use like this:
set ambiwidth=double
call test_option_not_set('ambiwidth')
Now the 'ambiwidth' option behaves like it was never changed,
even though the value is "double".
Only to be used for testing!
Can also be used as a YXXYmethod|:
GetOptionName()->test_option_not_set()
test_override({name}, {val}) *test_override()*
Overrides certain parts of Vim's internal processing to be able
to run tests. Only to be used for testing Vim!
The override is enabled when {val} is non-zero and removed
when {val} is zero.
Current supported values for {name} are:
{name} effect when {val} is non-zero
alloc_lines make a copy of every buffer line into allocated
memory, so that memory access errors can be found
by valgrind
autoload `import autoload` will load the script right
away, not postponed until an item is used
char_avail disable the char_avail() function
nfa_fail makes the NFA regexp engine fail to force a
fallback to the old engine
no_query_mouse do not query the mouse position for "dec"
terminals
no_wait_return set the "no_wait_return" flag. Not restored
with "ALL".
redraw disable the redrawing() function
redraw_flag ignore the RedrawingDisabled flag
starting reset the "starting" variable, see below
term_props reset all terminal properties when the version
string is detected
ui_delay time in msec to use in ui_delay(); overrules a
wait time of up to 3 seconds for messages
unreachable no error for code after `:throw` and `:return`
uptime overrules sysinfo.uptime
vterm_title setting the window title by a job running in a
terminal window
ALL clear all overrides, except alloc_lines ({val} is
not used)
"starting" is to be used when a test should behave like
startup was done. Since the tests are run by sourcing a
script the "starting" variable is non-zero. This is usually a
good thing (tests run faster), but sometimes this changes
behavior in a way that the test doesn't work properly.
When using:
call test_override('starting', 1)
The value of "starting" is saved. It is restored by:
call test_override('starting', 0)
To make sure the flag is reset later using `:defer` can be
useful:
call test_override('unreachable', 1)
defer call test_override('unreachable', 0)
Can also be used as a YXXYmethod|:
GetOverrideVal()-> test_override('starting')
test_refcount({expr}) *test_refcount()*
Return the reference count of {expr}. When {expr} is of a
type that does not have a reference count, returns -1. Only
to be used for testing.
Can also be used as a YXXYmethod|:
GetVarname()->test_refcount()
test_setmouse({row}, {col}) *test_setmouse()*
Set the mouse position to be used for the next mouse action.
{row} and {col} are one based.
For example:
call test_setmouse(4, 20)
call feedkeys("\<LeftMouse>", "xt")
test_settime({expr}) *test_settime()*
Set the time Vim uses internally. Currently only used for
timestamps in the history, as they are used in viminfo, and
for undo.
Using a value of 1 makes Vim not sleep after a warning or
error message.
{expr} must evaluate to a number. When the value is zero the
normal behavior is restored.
Can also be used as a YXXYmethod|:
GetTime()->test_settime()
test_srand_seed([seed]) *test_srand_seed()*
When [seed] is given this sets the seed value used by
`srand()`. When omitted the test seed is removed.
test_unknown() *test_unknown()*
Return a value with unknown type. Only useful for testing.
test_void() *test_void()*
Return a value with void type. Only useful for testing.
==============================================================================
3. Assert functions *assert-functions-details*
assert_beeps({cmd}) *assert_beeps()*
Run {cmd} and add an error message to |v:errors| if it does
NOT produce a beep or visual bell.
Also see |assert_fails()|, |assert_nobeep()| and
|assert-return|.
Can also be used as a YXXYmethod|:
GetCmd()->assert_beeps()
*assert_equal()*
assert_equal({expected}, {actual} [, {msg}])
When {expected} and {actual} are not equal an error message is
added to |v:errors| and 1 is returned. Otherwise zero is
returned. |assert-return|
The error is in the form "Expected {expected} but got
{actual}". When {msg} is present it is prefixed to that.
There is no automatic conversion, the String "4" is different
from the Number 4. And the number 4 is different from the
Float 4.0. The value of 'ignorecase' is not used here, case
always matters.
Example:
assert_equal('foo', 'bar')
Will result in a string to be added to YXXYv:errors|:
test.vim line 12: Expected 'foo' but got 'bar'
Can also be used as a |method|, the base is passed as the
second argument:
mylist->assert_equal([1, 2, 3])
*assert_equalfile()*
assert_equalfile({fname-one}, {fname-two} [, {msg}])
When the files {fname-one} and {fname-two} do not contain
exactly the same text an error message is added to |v:errors|.
Also see |assert-return|.
When {fname-one} or {fname-two} does not exist the error will
mention that.
Mainly useful with |terminal-diff|.
Can also be used as a YXXYmethod|:
GetLog()->assert_equalfile('expected.log')
assert_exception({error} [, {msg}]) *assert_exception()*
When v:exception does not contain the string {error} an error
message is added to |v:errors|. Also see |assert-return|.
This can be used to assert that a command throws an exception.
Using the error number, followed by a colon, avoids problems
with translations:
try
commandthatfails
call assert_false(1, 'command should have failed')
catch
call assert_exception('E492:')
endtry
*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 or when {error} is not found in the
error message. Also see |assert-return|.
*E856*
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.
If there is only one error then both patterns must match. This
can be used to check that there is only one 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.
*E1115*
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.
*E1116*
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 YXXYmethod|:
GetCmd()->assert_fails('E99:')
assert_false({actual} [, {msg}]) *assert_false()*
When {actual} is not false an error message is added to
|v:errors|, like with |assert_equal()|.
The error is in the form "Expected False but got {actual}".
When {msg} is present it is prepended to that.
Also see |assert-return|.
A value is false when it is zero. When {actual} is not a
number the assert fails.
Can also be used as a YXXYmethod|:
GetResult()->assert_false()
assert_inrange({lower}, {upper}, {actual} [, {msg}]) *assert_inrange()*
This asserts number and |Float| values. When {actual} is lower
than {lower} or higher than {upper} an error message is added
to |v:errors|. Also see |assert-return|.
The error is in the form "Expected range {lower} - {upper},
but got {actual}". When {msg} is present it is prefixed to
that.
*assert_match()*
assert_match({pattern}, {actual} [, {msg}])
When {pattern} does not match {actual} an error message is
added to |v:errors|. Also see |assert-return|.
The error is in the form "Pattern {pattern} does not match
{actual}". When {msg} is present it is prefixed to that.
{pattern} is used as with |=~|: The matching is always done
like 'magic' was set and 'cpoptions' is empty, no matter what
the actual value of 'magic' or 'cpoptions' is.
{actual} is used as a string, automatic conversion applies.
Use "^" and "$" to match with the start and end of the text.
Use both to match the whole text.
Example:
assert_match('^f.*o$', 'foobar')
Will result in a string to be added to YXXYv:errors|:
test.vim line 12: Pattern '^f.*o$' does not match 'foobar'
Can also be used as a YXXYmethod|:
getFile()->assert_match('foo.*')
assert_nobeep({cmd}) *assert_nobeep()*
Run {cmd} and add an error message to |v:errors| if it
produces a beep or visual bell.
Also see |assert_beeps()|.
Can also be used as a YXXYmethod|:
GetCmd()->assert_nobeep()
*assert_notequal()*
assert_notequal({expected}, {actual} [, {msg}])
The opposite of `assert_equal()`: add an error message to
|v:errors| when {expected} and {actual} are equal.
Also see |assert-return|.
Can also be used as a YXXYmethod|:
mylist->assert_notequal([1, 2, 3])
*assert_notmatch()*
assert_notmatch({pattern}, {actual} [, {msg}])
The opposite of `assert_match()`: add an error message to
|v:errors| when {pattern} matches {actual}.
Also see |assert-return|.
Can also be used as a YXXYmethod|:
getFile()->assert_notmatch('bar.*')
assert_report({msg}) *assert_report()*
Report a test failure directly, using String {msg}.
Always returns one.
Can also be used as a YXXYmethod|:
GetMessage()->assert_report()
assert_true({actual} [, {msg}]) *assert_true()*
When {actual} is not true an error message is added to
|v:errors|, like with |assert_equal()|.
Also see |assert-return|.
A value is TRUE when it is a non-zero number. When {actual}
is not a number the assert fails.
When {msg} is given it precedes the default message.
Can also be used as a YXXYmethod|:
GetResult()->assert_true()
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