master 3b40501: Replace Unix commands with Emacs in process tests.

[Philipp Stephani]

branch: master
commit 3b4050154e3f72c06501cd9a5ad83841b92c7bd6
Author: Philipp Stephani <phst@google.com>
Commit: Philipp Stephani <phst@google.com>

    Replace Unix commands with Emacs in process tests.
    
    That way, the tests only depend on Emacs, and not on utilities that
    might not be available during test time.
    
    * test/src/process-tests.el (process-tests--eval)
    (process-tests--emacs-command, process-tests--emacs-binary)
    (process-tests--dump-file)
    (process-tests--usable-file-for-reinvoke): New helper functions.
    (process-tests/sentinel-called)
    (process-tests/sentinel-with-multiple-processes): Use them.
---
 test/src/process-tests.el | 80 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 71 insertions(+), 9 deletions(-)

diff --git a/test/src/process-tests.el b/test/src/process-tests.el
index d2a98dc..949f735 100644
--- a/test/src/process-tests.el
+++ b/test/src/process-tests.el
@@ -736,15 +736,16 @@ Return nil if that can't be determined."
 
 (ert-deftest process-tests/sentinel-called ()
   "Check that sentinels are called after processes finish"
-  (let ((echo (executable-find "echo")))
-    (skip-unless echo)
+  (let ((command (process-tests--emacs-command)))
+    (skip-unless command)
     (dolist (conn-type '(pipe pty))
       (ert-info ((format "Connection type: %s" conn-type))
         (process-tests--with-processes processes
           (let* ((calls ())
                  (process (make-process
                            :name "echo"
-                           :command (list echo "first")
+                           :command (process-tests--eval
+                                     command '(print "first"))
                            :noquery t
                            :connection-type conn-type
                            :coding 'utf-8-unix
@@ -759,17 +760,16 @@ Return nil if that can't be determined."
 (ert-deftest process-tests/sentinel-with-multiple-processes ()
   "Check that sentinels are called in time even when other processes
 have written output."
-  (let ((echo (executable-find "echo"))
-        (bash (executable-find "bash")))
-    (skip-unless echo)
-    (skip-unless bash)
+  (let ((command (process-tests--emacs-command)))
+    (skip-unless command)
     (dolist (conn-type '(pipe pty))
       (ert-info ((format "Connection type: %s" conn-type))
         (process-tests--with-processes processes
           (let* ((calls ())
                  (process (make-process
                            :name "echo"
-                           :command (list echo "first")
+                           :command (process-tests--eval
+                                     command '(print "first"))
                            :noquery t
                            :connection-type conn-type
                            :coding 'utf-8-unix
@@ -779,7 +779,9 @@ have written output."
             (push process processes)
             (push (make-process
                    :name "bash"
-                   :command (list bash "-c" "sleep 10 && echo second")
+                   :command (process-tests--eval
+                             command
+                             '(progn (sleep-for 10) (print "second")))
                    :noquery t
                    :connection-type conn-type)
                   processes)
@@ -787,5 +789,65 @@ have written output."
             (should (equal calls
                            (list (list process "finished\n"))))))))))
 
+(defun process-tests--eval (command form)
+  "Return a command that evaluates FORM in an Emacs subprocess.
+COMMAND must be a list returned by
+`process-tests--emacs-command'."
+  (let ((print-gensym t)
+        (print-circle t)
+        (print-length nil)
+        (print-level nil)
+        (print-escape-control-characters t)
+        (print-escape-newlines t)
+        (print-escape-multibyte t)
+        (print-escape-nonascii t))
+    `(,@command "--quick" "--batch" ,(format "--eval=%S" form))))
+
+(defun process-tests--emacs-command ()
+  "Return a command to reinvoke the current Emacs instance.
+Return nil if that doesn't appear to be possible."
+  (when-let ((binary (process-tests--emacs-binary))
+             (dump (process-tests--dump-file)))
+    (cons binary
+          (unless (eq dump :not-needed)
+            (list (concat "--dump-file="
+                          (file-name-unquote dump)))))))
+
+(defun process-tests--emacs-binary ()
+  "Return the filename of the currently running Emacs binary.
+Return nil if that can't be determined."
+  (and (stringp invocation-name)
+       (not (file-remote-p invocation-name))
+       (not (file-name-absolute-p invocation-name))
+       (stringp invocation-directory)
+       (not (file-remote-p invocation-directory))
+       (file-name-absolute-p invocation-directory)
+       (when-let ((file (process-tests--usable-file-for-reinvoke
+                         (expand-file-name invocation-name
+                                           invocation-directory))))
+         (and (file-executable-p file) file))))
+
+(defun process-tests--dump-file ()
+  "Return the filename of the dump file used to start Emacs.
+Return nil if that can't be determined.  Return `:not-needed' if
+Emacs wasn't started with a dump file."
+  (if-let ((stats (and (fboundp 'pdumper-stats) (pdumper-stats))))
+      (when-let ((file (process-tests--usable-file-for-reinvoke
+                        (cdr (assq 'dump-file-name stats)))))
+        (and (file-readable-p file) file))
+    :not-needed))
+
+(defun process-tests--usable-file-for-reinvoke (filename)
+  "Return a version of FILENAME that can be used to reinvoke Emacs.
+Return nil if FILENAME doesn't exist."
+  (when (and (stringp filename)
+             (not (file-remote-p filename)))
+    (cl-callf file-truename filename)
+    (and (stringp filename)
+         (not (file-remote-p filename))
+         (file-name-absolute-p filename)
+         (file-regular-p filename)
+         filename)))
+
 (provide 'process-tests)
 ;;; process-tests.el ends here