python-pytest.el

;;; python-pytest.el --- helpers to run pytest -*- lexical-binding: t; -*-

;; Author: wouter bolsterlee <wouter@bolsterl.ee>
;; Version: 3.3.0
;; Package-Requires: ((emacs "24.4") (dash "2.18.0") (transient "0.3.7") (projectile "0.14.0") (s "1.12.0"))
;; Keywords: pytest, test, python, languages, processes, tools
;; URL: https://github.com/wbolster/emacs-python-pytest
;;
;; This file is not part of GNU Emacs.

;;; License:

;; 3-clause "new bsd"; see readme for details.

;;; Commentary:

;; This package provides helpers to run pytest. See README for details.

;;; Code:

(require 'cl-lib)
(require 'comint)
(require 'compile)
(require 'python)

(require 'dash)
(require 'transient)
(require 'projectile)
(require 's)

(defgroup python-pytest nil
  "pytest integration"
  :group 'python
  :prefix "python-pytest-")

(defcustom python-pytest-confirm nil
  "Whether to edit the command in the minibuffer before execution.

By default, pytest will be executed without showing a minibuffer prompt.
This can be changed on a case by case basis by using a prefix argument
\(\\[universal-argument]\) when invoking a command.

When t, this toggles the behaviour of the prefix argument."
  :group 'python-pytest
  :type 'boolean)

(defcustom python-pytest-executable "pytest"
  "The name of the pytest executable."
  :group 'python-pytest
  :type 'string)

(defcustom python-pytest-setup-hook nil
  "Hooks to run before a pytest process starts."
  :group 'python-pytest
  :type 'hook)

(defcustom python-pytest-started-hook nil
  "Hooks to run after a pytest process starts."
  :group 'python-pytest
  :type 'hook)

(defcustom python-pytest-finished-hook nil
  "Hooks to run after a pytest process finishes."
  :group 'python-pytest
  :type 'hook)

(defcustom python-pytest-buffer-name "*pytest*"
  "Name of the pytest output buffer."
  :group 'python-pytest
  :type 'string)

(defcustom python-pytest-project-name-in-buffer-name t
  "Whether to include the project name in the buffer name.

This is useful when working on multiple projects simultaneously."
  :group 'python-pytest
  :type 'boolean)

(defcustom python-pytest-pdb-track t
  "Whether to automatically track output when pdb is spawned.

This results in automatically opening source files during debugging."
  :group 'python-pytest
  :type 'boolean)

(defcustom python-pytest-strict-test-name-matching nil
  "Whether to require a strict match for the ‘test this function’ heuristic.

This influences the ‘test this function’ behaviour when editing a
non-test function, e.g. ‘foo()’.

When nil (the default), the current function name will be used as
a pattern to run the corresponding tests, which will match
‘test_foo()’ as well as ‘test_foo_xyz()’.

When non-nil only ‘test_foo()’ will match, and nothing else."
  :group 'python-pytest
  :type 'boolean)

(defcustom python-pytest-unsaved-buffers-behavior 'ask-all
  "Whether to ask whether unsaved buffers should be saved before running pytest."
  :group 'python-pytest
  :type '(choice (const :tag "Ask for all project buffers" ask-all)
                 (const :tag "Ask for current buffer" ask-current)
                 (const :tag "Save all project buffers" save-all)
                 (const :tag "Save current buffer" save-current)
                 (const :tag "Ignore" nil)))

(defvar python-pytest--history nil
  "History for pytest invocations.")

(defvar python-pytest--project-last-command (make-hash-table :test 'equal)
  "Last executed command lines, per project.")

(defvar-local python-pytest--current-command nil
  "Current command; used in python-pytest-mode buffers.")

;;;###autoload (autoload 'python-pytest-dispatch "python-pytest" nil t)
(transient-define-prefix python-pytest-dispatch ()
  "Show popup for running pytest."
  :man-page "pytest"
  :incompatible '(("--exitfirst" "--maxfail="))
  :value '("--color")
  ["Output"
   [("-c" "color" "--color")
    ("-q" "quiet" "--quiet")
    ("-s" "no output capture" "--capture=no")
    (python-pytest:-v)]]
  ["Selection, filtering, ordering"
   [(python-pytest:-k)
    (python-pytest:-m)
    "                                          "] ;; visual alignment
   [("--dm" "run doctests" "--doctest-modules")
    ("--nf" "new first" "--new-first")
    ("--sw" "stepwise" "--stepwise")
    ("--co" "collect only" "--collect-only")]]
  ["Failures, errors, warnings, debugging"
   [("-l" "show locals" "--showlocals")
    ("-p" "debug on error" "--pdb")
    ("-x" "exit after first failure" "--exitfirst")
    (python-pytest:-W)]
   [("--ff" "failed first" "--failed-first")
    ("--ft" "full tracebacks" "--full-trace")
    ("--mf" "exit after N failures or errors" "--maxfail=")
    ("--rx" "run xfail tests" "--runxfail")
    (python-pytest:--tb)
    ("--tr" "debug on each test" "--trace")]]
  ["Options for pytest-xdist"
   [(python-pytest:-n)]
   [("-f" "loop on failure" "--looponfail")]]
  ["Run tests"
   [("t" "all" python-pytest)]
   [("r" "repeat" python-pytest-repeat)
    ("x" "last failed" python-pytest-last-failed)]
   [("f" "file (dwim)" python-pytest-file-dwim)
    ("F" "file (this)" python-pytest-file)]
   [("m" "files" python-pytest-files)
    ("M" "directories" python-pytest-directories)]
   [("d" "def/class (dwim)" python-pytest-function-dwim)
    ("D" "def/class (this)" python-pytest-function)]])

(define-obsolete-function-alias 'python-pytest-popup 'python-pytest-dispatch "2.0.0")

;;;###autoload
(defun python-pytest (&optional args)
  "Run pytest with ARGS.

With a prefix argument, allow editing."
  (interactive (list (transient-args 'python-pytest-dispatch)))
  (python-pytest--run
   :args args
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-file (file &optional args)
  "Run pytest on FILE, using ARGS.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (buffer-file-name)
    (transient-args 'python-pytest-dispatch)))
  (python-pytest--run
   :args args
   :file file
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-file-dwim (file &optional args)
  "Run pytest on FILE, intelligently finding associated test modules.

When run interactively, this tries to work sensibly using
the current file.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (buffer-file-name)
    (transient-args 'python-pytest-dispatch)))
  (python-pytest-file (python-pytest--sensible-test-file file) args))

;;;###autoload
(defun python-pytest-files (files &optional args)
  "Run pytest on FILES, using ARGS.

When run interactively, this allows for interactive file selection.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (python-pytest--select-test-files :type 'file)
    (transient-args 'python-pytest-dispatch)))
  (setq args (-concat args (-map 'python-pytest--shell-quote files)))
  (python-pytest--run
   :args args
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-directories (directories &optional args)
  "Run pytest on DIRECTORIES, using ARGS.

When run interactively, this allows for interactive directory selection.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (python-pytest--select-test-files :type 'directory)
    (transient-args 'python-pytest-dispatch)))
  (setq args (-concat args (-map 'python-pytest--shell-quote directories)))
  (python-pytest--run
   :args args
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-function (file func args)
  "Run pytest on FILE with FUNC (or class).

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (buffer-file-name)
    (python-pytest--current-defun)
    (transient-args 'python-pytest-dispatch)))
  (python-pytest--run
   :args args
   :file file
   :func func
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-function-dwim (file func args)
  "Run pytest on FILE with FUNC (or class).

When run interactively, this tries to work sensibly using
the current file and function around point.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive
   (list
    (buffer-file-name)
    (python-pytest--current-defun)
    (transient-args 'python-pytest-dispatch)))
  (unless (python-pytest--test-file-p file)
    (setq
     file (python-pytest--sensible-test-file file)
     func (python-pytest--make-test-name func))
    (unless python-pytest-strict-test-name-matching
      (let ((k-option (-first (-partial #'s-prefix-p "-k") args)))
        (when k-option
          ;; try to use the existing ‘-k’ option in a sensible way
          (setq args (-remove-item k-option args)
                k-option (-->
                          k-option
                          (s-chop-prefix "-k" it)
                          (s-trim it)
                          (if (s-contains-p " " it) (format "(%s)" it) it))))
        (setq args (-snoc
                    args
                    (python-pytest--shell-quote file)
                    (if k-option
                        (format "-k %s and %s" func k-option)
                      (format "-k %s" func)))
              file nil
              func nil))))
  (python-pytest--run
   :args args
   :file file
   :func func
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-last-failed (&optional args)
  "Run pytest, only executing previous test failures.

Additional ARGS are passed along to pytest.
With a prefix argument, allow editing."
  (interactive (list (transient-args 'python-pytest-dispatch)))
  (python-pytest--run
   :args (-snoc args "--last-failed")
   :edit current-prefix-arg))

;;;###autoload
(defun python-pytest-repeat ()
  "Run pytest with the same argument as the most recent invocation.

With a prefix ARG, allow editing."
  (interactive)
  (let ((command (gethash
                  (python-pytest--project-root)
                  python-pytest--project-last-command)))
    (when python-pytest--current-command
      ;; existing python-pytest-mode buffer; reuse command
      (setq command python-pytest--current-command))
    (unless command
      (user-error "No previous pytest run for this project"))
    (python-pytest--run-command
     :command command
     :edit current-prefix-arg)))


;; internal helpers

(define-derived-mode python-pytest-mode
  comint-mode "pytest"
  "Major mode for pytest sessions (derived from comint-mode)."
  (compilation-setup))

(defvar python-pytest-finished-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map compilation-minor-mode-map)
    (define-key map [remap recompile] #'python-pytest-repeat)
    map)
  "Keymap for `python-pytest-mode' major mode.")

(cl-defun python-pytest--run (&key args file func edit)
  "Run pytest for the given arguments."
  (setq args (python-pytest--transform-arguments args))
  (when (and file (file-name-absolute-p file))
    (setq file (python-pytest--relative-file-name file)))
  (when func
    (setq func (s-replace "." "::" func)))
  (let ((command)
        (thing (cond
                ((and file func) (format "%s::%s" file func))
                (file file))))
    (when thing
      (setq args (-snoc args (python-pytest--shell-quote thing))))
    (setq args (cons python-pytest-executable args)
          command (s-join " " args))
    (python-pytest--run-command
     :command command
     :edit edit)))

(cl-defun python-pytest--run-command (&key command edit)
  "Run a pytest command line."
  (python-pytest--maybe-save-buffers)
  (let* ((default-directory (python-pytest--project-root)))
    (when python-pytest-confirm
      (setq edit (not edit)))
    (when edit
      (setq command
            (read-shell-command
             "Command: "
             command 'python-pytest--history)))
    (add-to-history 'python-pytest--history command)
    (setq python-pytest--history (-uniq python-pytest--history))
    (puthash (python-pytest--project-root) command
             python-pytest--project-last-command)
    (python-pytest--run-as-comint :command command)))

(cl-defun python-pytest--run-as-comint (&key command)
  "Run a pytest comint session for COMMAND."
  (let* ((buffer (python-pytest--get-buffer))
         (process (get-buffer-process buffer)))
    (with-current-buffer buffer
      (display-buffer buffer)
      (when (comint-check-proc buffer)
        (unless (or compilation-always-kill
                    (yes-or-no-p "Kill running pytest process?"))
          (user-error "Aborting; pytest still running")))
      (when process
        (delete-process process))
      (let ((inhibit-read-only t))
        (erase-buffer))
      (unless (eq major-mode 'python-pytest-mode)
        (python-pytest-mode))
      (compilation-forget-errors)
      (insert (format "cwd: %s\ncmd: %s\n\n" default-directory command))
      (setq python-pytest--current-command command)
      (when python-pytest-pdb-track
        (add-hook
         'comint-output-filter-functions
         'python-pdbtrack-comint-output-filter-function
         nil t))
      (run-hooks 'python-pytest-setup-hook)
      (make-comint-in-buffer
       "pytest" buffer
       (if (eq system-type 'windows-nt) "cmdproxy" "sh")
       nil "-c" command)
      (run-hooks 'python-pytest-started-hook)
      (setq process (get-buffer-process buffer))
      (set-process-sentinel process #'python-pytest--process-sentinel))))

(defun python-pytest--shell-quote (s)
  "Quote S for use in a shell command. Like `shell-quote-argument', but prettier."
  (if (s-equals-p s (shell-quote-argument s))
      s
    (format "'%s'" (s-replace "'" "'\"'\"'" s))))

(defun python-pytest--get-buffer ()
  "Get a create a suitable compilation buffer."
  (if (eq major-mode 'python-pytest-mode)
      (current-buffer)  ;; re-use buffer
    (let ((name python-pytest-buffer-name))
      (when python-pytest-project-name-in-buffer-name
        (setq name (format "%s<%s>" name (python-pytest--project-name))))
      (get-buffer-create name))))

(defun python-pytest--process-sentinel (proc _state)
  "Process sentinel helper to run hooks after PROC finishes."
  (with-current-buffer (process-buffer proc)
    (compilation-mode)
    (read-only-mode -1)		  ;; required for python-pytest-repeat
    (use-local-map python-pytest-finished-mode-map)
    (run-hooks 'python-pytest-finished-hook)))

(defun python-pytest--transform-arguments (args)
  "Transform ARGS so that pytest understands them."
  (-->
   args
   (python-pytest--switch-to-option it "--color" "--color=yes" "--color=no")))

(defun python-pytest--switch-to-option (args name on-replacement off-replacement)
  "Look in ARGS for switch NAME and turn it into option with a value.

When present ON-REPLACEMENT is substituted, else OFF-REPLACEMENT is appended."
  (if (-contains-p args name)
      (-replace name on-replacement args)
    (-snoc args off-replacement)))

(defun python-pytest--quote-string-option (args option)
  "Quote all values in ARGS with the prefix OPTION as shell strings."
  (--map-when
   (s-prefix-p option it)
   (let ((s it))
     (--> s
          (substring it (length option))
          (s-trim it)
          (python-pytest--shell-quote it)
          (format "%s %s" option it)))
   args))

(defun python-pytest--read-quoted-argument-for-short-flag (prompt initial-input history)
  "Read a quoted string for use as a argument after a short-form command line flag."
  (let* ((input (read-from-minibuffer prompt initial-input nil nil history))
         (quoted-input (python-pytest--shell-quote input))
         (formatted-input (format " %s" quoted-input)))
    formatted-input))

(transient-define-argument python-pytest:-k ()
  :description "only names matching expression"
  :class 'transient-option
  :argument "-k"
  :allow-empty nil
  :key "-k"
  :reader 'python-pytest--read-quoted-argument-for-short-flag)

(transient-define-argument python-pytest:-m ()
  :description "only marks matching expression"
  :class 'transient-option
  :argument "-m"
  :allow-empty nil
  :key "-m"
  :reader 'python-pytest--read-quoted-argument-for-short-flag)

(transient-define-argument python-pytest:-v ()
  :description "verbosity"
  :class 'transient-switches
  :key "-v"
  :argument-format "%s"
  :argument-regexp "^\\(--verbose\\|--verbose --verbose\\)$"
  :choices '("--verbose" "--verbose --verbose"))

(transient-define-argument python-pytest:-W ()
  :description "warnings"
  :class 'transient-option
  :key "-W"
  :argument "-W "
  :choices '("default" "error" "always" "module" "once" "ignore"))

(transient-define-argument python-pytest:--tb ()
  :description "traceback style"
  :class 'transient-option
  :key "--tb"
  :argument "--tb="
  :choices '("long" "short" "line" "native" "no"))

(transient-define-argument python-pytest:-n ()
  :description "number of processes"
  :class 'transient-option
  :key "-n"
  :argument "--numprocesses="
  :choices '("auto" "0" "1" "2" "4" "8" "16"))


;; python helpers

(defun python-pytest--current-defun ()
  "Detect the current function/class (if any)."
  (let* ((name
          (or (python-info-current-defun)
              (save-excursion
                ;; As a fallback, jumping seems to make it work on empty lines.
                (python-nav-beginning-of-defun)
                (python-nav-forward-statement)
                (python-info-current-defun))
              (user-error "No class/function found")))
         (name
          ;; Keep at most two parts, e.g. MyClass.do_something
          (s-join "." (-slice (s-split-up-to "\\." name 2) 0 2)))
         (name
          ;; If the first part starts with a lowercase letter, it is likely
          ;; a function, not a class. Keep the first part and discard
          ;; nested function names or nested class names, if any.
          (if (s-lowercase? (substring name 0 1))
              (car (s-split-up-to "\\." name 1))
            name)))
    name))

(defun python-pytest--make-test-name (func)
  "Turn function name FUNC into a name (hopefully) matching its test name.

Example: ‘MyABCThingy.__repr__’ becomes ‘test_my_abc_thingy_repr’."
  (-->
   func
   (s-replace "." "_" it)
   (s-snake-case it)
   (s-replace-regexp "_\+" "_" it)
   (s-chop-suffix "_" it)
   (s-chop-prefix "_" it)
   (format "test_%s" it)))


;; file/directory helpers

(defun python-pytest--project-name ()
  "Find the project name."
  (projectile-project-name))

(defun python-pytest--project-root ()
  "Find the project root directory."
  (let ((projectile-require-project-root nil))
    (projectile-compilation-dir)))

(defun python-pytest--relative-file-name (file)
  "Make FILE relative to the project root."
  ;; Note: setting default-directory gives different results
  ;; than providing a second argument to file-relative-name.
  (let ((default-directory (python-pytest--project-root)))
    (file-relative-name file)))

(defun python-pytest--test-file-p (file)
  "Tell whether FILE is a test file."
  (projectile-test-file-p file))

(defun python-pytest--find-test-file (file)
  "Find a test file associated to FILE, if any."
  (let ((test-file (projectile-find-matching-test file)))
    (unless test-file
      (user-error "No test file found"))
    test-file))

(defun python-pytest--sensible-test-file (file)
  "Return a sensible test file name for FILE."
  (if (python-pytest--test-file-p file)
      (python-pytest--relative-file-name file)
    (python-pytest--find-test-file file)))

(cl-defun python-pytest--select-test-files (&key type)
  "Interactively choose test files."
  (let* ((test-files
          (->> (projectile-project-files (python-pytest--project-root))
               (-sort 'string<)
               (projectile-sort-by-recentf-first)
               ;; show test files if any found, otherwise show everything
               (funcall (-orfn #'projectile-test-files #'identity))))
         (test-directories
          (->> test-files
               (-map 'file-name-directory)
               (-uniq)
               (-sort 'string<)))
         (candidates (if (eq type 'file) test-files test-directories))
         (prompt (if (eq type 'file) "Choose test files: " "Choose test directories: ")))
    (unless candidates
      (user-error "No test files or directories found"))
    (completing-read-multiple prompt candidates nil t)))

(defun python-pytest--maybe-save-buffers ()
  "Maybe save modified buffers."
  (cond
   ((memq python-pytest-unsaved-buffers-behavior '(ask-current save-current))
    ;; check only current buffer
    (when (and (buffer-modified-p)
               (or (eq python-pytest-unsaved-buffers-behavior 'save-current)
                   (y-or-n-p
                    (format "Save modified buffer (%s)? " (buffer-name)))))
      (save-buffer)))
   ((memq python-pytest-unsaved-buffers-behavior '(ask-all save-all))
    ;; check all project buffers
    (-when-let*
        ((buffers
          (projectile-buffers-with-file (projectile-project-buffers)))
         (modified-buffers
          (-filter 'buffer-modified-p buffers))
         (confirmed
          (or (eq python-pytest-unsaved-buffers-behavior 'save-all)
              (y-or-n-p
               (format "Save modified project buffers (%d)? "
                       (length modified-buffers))))))
      (--each modified-buffers
        (with-current-buffer it
          (save-buffer)))))
   (t nil)))


;; third party integration

(with-eval-after-load 'direnv
  (defvar direnv-non-file-modes)
  (add-to-list 'direnv-non-file-modes 'python-pytest-mode))


(provide 'python-pytest)
;;; python-pytest.el ends here