test: update documentation for test_emacs in test/README

[notmuch] / test / README

diff --git a/test/README b/test/README
index 8fbf78da57618f613e5ebb26736f5ef16b1fd7ad..a245bf121fec9b77c95325d9d2f51b9c4a933124 100644 (file)
--- a/test/README
+++ b/test/README
@@ -156,6 +156,13 @@ library for your script to use.
    will generate a failure and print the difference of the two
    strings.
 
+ test_expect_equal_file <output> <expected>
+
+   Identical to test_exepect_equal, except that <output> and
+   <expected> are files instead of strings.  This is a much more
+   robust method to compare formatted textual information, since it
+   also notices whitespace and closing newline differences.
+
  test_expect_equal_failure <output> <expected>
 
    This works similar to test_expect_equal (see above) but is used to
@@ -174,9 +181,13 @@ library for your script to use.
 
    This function executes the provided emacs lisp script within
    emacs. The script can be a sequence of emacs lisp expressions,
-   (that is, they will be evaluated within a progn form). The lisp
-   expressions can call `message' to generate output on stdout to be
-   examined by the calling test script.
+   (that is, they will be evaluated within a progn form). Emacs
+   stdout and stderr is not available, the common way to get output
+   is to save it to a file. There are some auxiliary functions
+   useful in emacs tests provided in test-lib.el. Do not use `setq'
+   for setting variables in Emacs tests because it affects other
+   tests that may run in the same Emacs instance.  Use `let' instead
+   so the scope of the changed variables is limited to a single test.
 
  test_done