Before the change, every Emacs test ran in a separate Emacs
instance. Starting Emacs many times wastes considerable time and
it gets worse as the test suite grows. The patch solves this by
using a single Emacs server and emacsclient(1) to run multiple
tests. Emacs server is started on the first test_emacs call and
stopped when test_done is called. We take care not to leave
orphan Emacs processes behind when test is terminated by whatever
reason: Emacs server runs a watchdog that periodically checks
that the test is still running.
Some tests need to provide user input. Before the change, this
was done using echo(1) to Emacs stdin. This no longer works and
instead `standard-input' variable is set accordingly to make
`read' return the appropriate string.
Before the change, the common Emacs test scheme was to print
buffer content to stdout and redirect it to a file or capture it
in a shell variable. This does not work if we switch to using
emacsclient(1) for running the tests, because you can not print
to the stdout in this case. (Actually, you can print to stdout
from Emacs server, but you can not capture the output on
emacsclient(1)).
The patch introduces new Emacs test auxiliary functions:
`test-output' and `test-visible-output'. These functions are
used to save buffer content to a file directly from Emacs. For
most tests the changes are trivial, because Emacs stdout output
was redirected to a file anyway. But some tests captured the
output in a shell variable and compare it with the expected
output using test_expect_equal. These tests are changed to use
files and test_expect_equal_file instead.
Note: even if we do not switch Emacs tests to emacsclient(1), the
patch makes tests cleaner and is an improvement.
The patch adds test-lib.el file for Emacs tests auxiliary stuff.
Currently, it implements two functions: `visible-buffer-string'
and `visible-buffer-substring'. These are similar to standard
counterparts without "visible-" prefix but exclude invisible
text. The functions are not used anywhere at the moment but
should be useful for testing hiding/showing in the Emacs
interface.
Edited-by: Carl Worth <cworth@cworth.org> Fixed "basic" test to ignore
new test-lib.el file.
