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Diffstat (limited to 'tests/test-chime-async-lifecycle.el')
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diff --git a/tests/test-chime-async-lifecycle.el b/tests/test-chime-async-lifecycle.el new file mode 100644 index 0000000..9ee0bee --- /dev/null +++ b/tests/test-chime-async-lifecycle.el @@ -0,0 +1,184 @@ +;;; test-chime-async-lifecycle.el --- Tests for async process lifecycle -*- lexical-binding: t; -*- + +;; Copyright (C) 2024-2026 Craig Jennings + +;; Author: Craig Jennings <c@cjennings.net> + +;; This program is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; This program is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with this program. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; Unit tests for the async child's lifecycle: the spawn-generation guard +;; that discards a late callback, and the kill path that reaps a child the +;; watchdog abandoned. +;; +;; Two failure modes motivate these. +;; +;; A watchdog interrupt races a child that finishes just past the timeout. +;; The late callback nils `chime--process' -- which by then holds the +;; *replacement* child -- so the overlap guard breaks and a third child can +;; spawn. It also resets the failure counter the watchdog just incremented. +;; +;; `interrupt-process' only asks. A child stuck in a blocking read ignores +;; SIGINT and lives on as a zombie, invisible because `chime--process' was +;; already nil'd. And async.el only kills a child's process buffer on a +;; zero exit, so every signalled child leaks its buffer. A persistent hang +;; leaks one per `chime-async-timeout' until Emacs restarts. +;; +;; Tests cover normal cases, boundary cases, and error cases. + +;;; Code: + +(require 'test-bootstrap (expand-file-name "test-bootstrap.el")) + +;;; Helpers + +(defun test-chime-lifecycle--reset () + "Reset the async state these tests touch." + (setq chime--process nil) + (setq chime--process-start-time nil) + (setq chime--process-generation 0) + (setq chime--consecutive-async-failures 0)) + +(defun test-chime-lifecycle--sleeper () + "Spawn a real, long-running child with a process buffer." + (let ((process (start-process "chime-lifecycle-test" + (generate-new-buffer " *chime-test*") + "sleep" "60"))) + (set-process-query-on-exit-flag process nil) + process)) + +;;; Normal Cases + +(chime-deftest test-chime-lifecycle-fresh-result-is-processed () + "A result from the current generation is processed." + (test-chime-lifecycle--reset) + (let ((handled nil)) + (setq chime--process-generation 3) + (cl-letf (((symbol-function 'chime--handle-async-success) + (lambda (_callback events) (setq handled events)))) + (chime--handle-async-result 3 #'ignore '(:an-event)) + (should (equal handled '(:an-event)))))) + +(chime-deftest test-chime-lifecycle-fresh-result-clears-process-state () + "Processing a fresh result clears the process handle and its start time." + (test-chime-lifecycle--reset) + (setq chime--process 'a-process) + (setq chime--process-start-time '(1 2)) + (cl-letf (((symbol-function 'chime--handle-async-success) (lambda (&rest _) nil))) + (chime--handle-async-result 0 #'ignore '()) + (should-not chime--process) + (should-not chime--process-start-time))) + +;;; Boundary Cases + +(chime-deftest test-chime-lifecycle-stale-result-is-discarded () + "A result from a superseded generation is ignored entirely." + (test-chime-lifecycle--reset) + (let ((handled nil) + (failed nil)) + ;; Generation 1 was abandoned; generation 2 is the live child. + (setq chime--process-generation 2) + (setq chime--process 'the-replacement-child) + (setq chime--consecutive-async-failures 1) + (cl-letf (((symbol-function 'chime--handle-async-success) + (lambda (&rest _) (setq handled t))) + ((symbol-function 'chime--record-async-failure) + (lambda (&rest _) (setq failed t)))) + (chime--handle-async-result 1 #'ignore '(:late-events)) + (should-not handled) + (should-not failed) + ;; The replacement child's handle survives. + (should (eq chime--process 'the-replacement-child)) + ;; The watchdog's failure count is not reset by the straggler. + (should (= chime--consecutive-async-failures 1))))) + +(chime-deftest test-chime-lifecycle-stale-error-result-is-discarded () + "A late error sexp from a superseded child is ignored too." + (test-chime-lifecycle--reset) + (let ((failed nil)) + (setq chime--process-generation 5) + (cl-letf (((symbol-function 'chime--record-async-failure) + (lambda (&rest _) (setq failed t)))) + (chime--handle-async-result 4 #'ignore '(async-signal error "boom")) + (should-not failed)))) + +(chime-deftest test-chime-lifecycle-watchdog-supersedes-the-generation () + "Interrupting a stale child bumps the generation, orphaning its callback." + (test-chime-lifecycle--reset) + (let ((now (current-time)) + (chime-async-timeout 10)) + (setq chime--process 'stuck-child) + (setq chime--process-start-time (time-subtract now (seconds-to-time 60))) + (setq chime--process-generation 7) + (cl-letf (((symbol-function 'process-live-p) (lambda (_p) t)) + ((symbol-function 'chime--kill-async-process) (lambda (_p) nil)) + ((symbol-function 'chime--record-async-failure) (lambda (&rest _) nil))) + (chime--interrupt-stale-process) + (should (= chime--process-generation 8)) + (should-not chime--process) + (should-not chime--process-start-time)))) + +(chime-deftest test-chime-lifecycle-stop-supersedes-the-generation () + "`chime--stop' orphans an in-flight callback and clears the counters." + (test-chime-lifecycle--reset) + (setq chime--process 'a-child) + (setq chime--process-start-time '(1 2)) + (setq chime--process-generation 2) + (setq chime--consecutive-async-failures 4) + (cl-letf (((symbol-function 'chime--kill-async-process) (lambda (_p) nil))) + (chime--stop) + (should (= chime--process-generation 3)) + (should-not chime--process) + (should-not chime--process-start-time) + ;; A restart must not resume with the old failure count. + (should (= chime--consecutive-async-failures 0)))) + +;;; Error Cases + +(chime-deftest test-chime-lifecycle-kill-async-process-kills-child-and-buffer () + "`chime--kill-async-process' leaves neither a live child nor its buffer. +`interrupt-process' only asks; async.el only reaps the buffer on a zero exit." + (let* ((process (test-chime-lifecycle--sleeper)) + (buffer (process-buffer process))) + (should (process-live-p process)) + (should (buffer-live-p buffer)) + (chime--kill-async-process process) + (should-not (process-live-p process)) + (should-not (buffer-live-p buffer)))) + +(chime-deftest test-chime-lifecycle-kill-async-process-tolerates-a-dead-child () + "Killing an already-dead process is a no-op, not an error." + (let ((process (test-chime-lifecycle--sleeper))) + (chime--kill-async-process process) + (should-not (condition-case nil + (progn (chime--kill-async-process process) nil) + (error t))))) + +(chime-deftest test-chime-lifecycle-kill-async-process-tolerates-nil () + "Killing nil is a no-op. `chime--stop' calls it unconditionally." + (should-not (condition-case nil + (progn (chime--kill-async-process nil) nil) + (error t)))) + +(chime-deftest test-chime-lifecycle-kill-async-process-silences-the-sentinel () + "The killed child's sentinel does not run, so async.el can't act on it." + (let ((process (test-chime-lifecycle--sleeper)) + (sentinel-ran nil)) + (set-process-sentinel process (lambda (&rest _) (setq sentinel-ran t))) + (chime--kill-async-process process) + (should-not sentinel-ran))) + +(provide 'test-chime-async-lifecycle) +;;; test-chime-async-lifecycle.el ends here |