Vimscript Built-in Functions: `assert_exception()`, `assert_fails()`, `assert_false()`, and `assert

the following to |v:errors|: test.vim line 12: baz: Expected 'foo' but got 'bar' ~ Parameters: ~ • {expected} (`any`) • {actual} (`any`) • {msg} (`any?`) Return: ~ (`0|1`) assert_equalfile({fname_one}, {fname_two}) *assert_equalfile()* 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. Parameters: ~ • {fname_one} (`string`) • {fname_two} (`string`) Return: ~ (`0|1`) 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: >vim try commandthatfails call assert_false(1, 'command should have failed') catch call assert_exception('E492:') endtry < Parameters: ~ • {error} (`any`) • {msg} (`any?`) Return: ~ (`0|1`) *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|. 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:". >vim call 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: >vim call 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: >vim call 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. Parameters: ~ • {cmd} (`string`) • {error} (`any?`) • {msg} (`any?`) • {lnum} (`integer?`) • {context} (`any?`) Return: ~ (`0|1`) 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 prefixed to that, along with the location of the assert when run from a script. Also see |assert-return|. A value is false when it is zero. When {actual} is not a number the assert fails. Parameters: ~ • {actual} (`any`) • {msg} (`any?`) Return: ~ (`0|1`) assert_inrange({lower}, {upper}, {actual} [, {msg}]) *assert_inrange()* This asserts number

This section of the Vimscript documentation details the `assert_exception()`, `assert_fails()`, and `assert_false()` functions. `assert_exception()` verifies if `v:exception` contains a specific error string. `assert_fails()` checks if a command produces an error and if the error message contains a specific string. `assert_false()` verifies if a given value is false (zero). Each function's syntax, parameters, return values, and usage examples are provided. There is also a description of the `assert_inrange()` function, which checks if a number is within a certain range.