Do not error normalizing a nil path under a container

`phpstan-get-command-args' starts with

    (config (or config (phpstan-normalize-path (phpstan-get-config-file))))

and `phpstan-get-config-file' returns nil when the project has no
phpstan.neon and `phpstan-config-file' is unset.  For a container
executable `phpstan-normalize-path' then passed that nil to
`replace-regexp-in-string', raising `(wrong-type-argument arrayp nil)'.
The local case was unaffected, since it returns `(or source
source-original)' without touching the path.

So `M-x phpstan-analyze-project', `phpstan-analyze-this-file', flycheck,
and flymake all errored under `(phpstan-executable . docker)' /
`container' whenever the project had no config file -- which
`phpstan-enable-on-no-config-file' explicitly allows (Composer autoload is
enough to enable PHPStan).

Guard `phpstan-normalize-path' at the source: a nil path falls through to
the `(or source source-original)' branch instead of the container
rewrite, so it returns nil (or the optional SOURCE fallback) rather than
erroring.  Fixing it in the one function protects every caller.  With
config nil the command line now simply omits `-c', which is correct.

Author: zonuexe

CHANGELOG.md

@@ -37,6 +37,7 @@ All notable changes of the `phpstan.el` are documented in this file using the [K
 * Fix editor mode detection asking the wrong program for its version.  Only the first element of the command line was probed, which is the container runtime for `(phpstan-executable . docker)` / `container` and `php` for a PHAR without the executable bit — so `docker --version` and `php --version` were parsed as PHPStan versions (`d1c06ef`, `Technologies`) and editor mode was silently disabled for every setup except a directly executable `phpstan`.
 * `phpstan-version` and `phpstan-editor-mode-available-p` now take the whole command line, as returned by `phpstan-get-executable-and-args`.  A bare string is still accepted.  `phpstan-version` no longer merges STDERR into the version string, which a container runtime pollutes with its progress report.
 * Fix `declare-function` forms for `tramp` that quoted the function name and argument list (and misspelled `tramp` as `tamp`), so the byte compiler warned that `tramp-dissect-file-name` might not be defined at runtime.
+* Fix a container run erroring when the project has no configuration file.  `phpstan-normalize-path` was handed the nil from `phpstan-get-config-file` and passed it to `replace-regexp-in-string`; it now returns nil for a nil path, so the command line simply omits `-c`.
 
 ### Removed
 

phpstan.el

@@ -393,16 +393,19 @@ such a command line still needs project paths rewritten to its mount point."
 
 If neither `phpstan-replace-path-prefix' nor a container executable is set,
 it returns the value of `SOURCE' as it is."
-  (let ((root-directory (expand-file-name (php-project-get-root-dir)))
-        (prefix
+  (let ((prefix
          (or phpstan-replace-path-prefix
              (and (phpstan--container-executable-p) "/app"))))
-    (if prefix
-        (expand-file-name
-         (replace-regexp-in-string (concat "\\`" (regexp-quote root-directory))
-                                   ""
-                                   source-original t t)
-         prefix)
+    ;; SOURCE-ORIGINAL is nil when there is no path to normalize, e.g. when
+    ;; `phpstan-get-config-file' finds no configuration.  Fall through rather
+    ;; than passing nil to `replace-regexp-in-string', which would error.
+    (if (and prefix source-original)
+        (let ((root-directory (expand-file-name (php-project-get-root-dir))))
+          (expand-file-name
+           (replace-regexp-in-string (concat "\\`" (regexp-quote root-directory))
+                                     ""
+                                     source-original t t)
+           prefix))
       (or source source-original))))
 
 (defun phpstan-get-level ()

test/phpstan-test.el

@@ -122,6 +122,20 @@
               (phpstan-replace-path-prefix nil))
           (should (equal src (phpstan-normalize-path src))))))))
 
+(ert-deftest phpstan-test-normalize-path-nil ()
+  "A nil path yields nil rather than erroring, even under a container.
+`phpstan-get-config-file' returns nil when a project has no configuration,
+and a containerized run would otherwise pass that nil to
+`replace-regexp-in-string'."
+  (cl-letf (((symbol-function 'php-project-get-root-dir) (lambda () "/proj/")))
+    (let ((phpstan-replace-path-prefix nil))
+      (dolist (exe '(docker container ("docker" "run" "img") nil "/bin/phpstan"))
+        (let ((phpstan-executable exe))
+          (should-not (phpstan-normalize-path nil))))
+      ;; The optional SOURCE fallback still applies when it is given.
+      (let ((phpstan-executable 'docker))
+        (should (equal "fallback" (phpstan-normalize-path nil "fallback")))))))
+
 ;;; Command line construction
 
 (defmacro phpstan-test--with-stubbed-project (&rest body)
@@ -184,5 +198,16 @@ survive `expand-file-name' on every platform."
         (should (member (expand-file-name "phpstan.neon" "/app") args))
         (should-not (member (phpstan-get-config-file) args))))))
 
+(ert-deftest phpstan-test-command-args-without-config-under-container ()
+  "A container run with no configuration file must not error.
+`phpstan-get-config-file' returns nil then, and normalizing it used to
+error; the command line should simply omit the `-c' flag."
+  (phpstan-test--with-stubbed-project
+    (cl-letf (((symbol-function 'phpstan-get-config-file) (lambda () nil)))
+      (let ((phpstan-executable 'docker))
+        (let ((args (phpstan-get-command-args :include-executable t)))
+          (should-not (member "-c" args))
+          (should (member "analyze" args)))))))
+
 (provide 'phpstan-test)
 ;;; phpstan-test.el ends here