Fix file/directory handling in cider-expected-ns

* Use `file-truename` to relax the need for the given path to be absolute
* Only consider actual directories on the classpath
* Use `file-in-directory-p` and `file-relative-name` rather than
  `string-prefix-p` and `substring`

Author: cichli

CHANGELOG.md

@@ -10,6 +10,7 @@
 * Fix values for `cider-preferred-build-tool` variable.
 * Fix value and safe property for `cider-allow-jack-in-without-project` variable.
 * `cider-ns-save-files-on-refresh` will now save any modified buffers visiting files on the classpath, rather than just in the current project.
+* `cider-expected-ns` no longer requires an absolute path as its argument, and now internally handles paths canonically and consistently.
 
 ## 0.20.0 (2019-01-14)
 
@@ -41,7 +42,6 @@
 
 ### Bug fixes
 
-* `cider-expected-ns` no longer requires an absolute path as its argument, and now internally handles paths canonically and consistently.
 * [#2474](https://github.com/clojure-emacs/cider/issues/2474): Fix incorrect detection of output and out-of-order printing.
 * [#2514](https://github.com/clojure-emacs/cider/issues/2514): Don't auto-jump to warnings when `cider-auto-jump-to-error` is set to 'errors-only.
 * [#2453](https://github.com/clojure-emacs/cider/issues/2453): Make it possible to debug deftype methods by direct insertion of #dbg and #break readers into the deftype methods.

cider-client.el

@@ -114,22 +114,22 @@ will return nil instead of \"user\"."
 
 (defun cider-expected-ns (&optional path)
   "Return the namespace string matching PATH, or nil if not found.
-PATH is expected to be an absolute file path.  If PATH is nil, use the path
-to the file backing the current buffer.  The command falls back to
-`clojure-expected-ns' in the absence of an active nREPL connection."
+If PATH is nil, use the path to the file backing the current buffer.  The
+command falls back to `clojure-expected-ns' in the absence of an active
+nREPL connection."
   (if (cider-connected-p)
-      (let* ((path (or path (file-truename (buffer-file-name))))
+      (let* ((path (file-truename (or path buffer-file-name)))
              (relpath (thread-last (cider-sync-request:classpath)
-                        (seq-map
-                         (lambda (cp)
-                           (when (string-prefix-p cp path)
-                             (substring path (length cp)))))
+                        (seq-filter #'file-directory-p)
+                        (seq-map (lambda (dir)
+                                   (when (file-in-directory-p path dir)
+                                     (file-relative-name path dir))))
                         (seq-filter #'identity)
                         (seq-sort (lambda (a b)
                                     (< (length a) (length b))))
                         (car))))
         (if relpath
-            (thread-last (substring relpath 1) ; remove leading /
+            (thread-last relpath
               (file-name-sans-extension)
               (replace-regexp-in-string "/" ".")
               (replace-regexp-in-string "_" "-"))

test/cider-client-tests.el

@@ -109,10 +109,15 @@
             :to-throw 'user-error)))
 
 (describe "cider-expected-ns"
-  (before-all
+  (before-each
     (spy-on 'cider-connected-p :and-return-value t)
     (spy-on 'cider-sync-request:classpath :and-return-value
-            '("/a" "/b" "/c" "/c/inner" "/base/clj" "/base/clj-dev")))
+            '("/a" "/b" "/c" "/c/inner" "/base/clj" "/base/clj-dev"))
+    (spy-on 'file-directory-p :and-return-value t)
+    (spy-on 'file-in-directory-p :and-call-fake (lambda (file dir)
+                                                  (string-prefix-p dir file)))
+    (spy-on 'file-relative-name :and-call-fake (lambda (file dir)
+                                                 (substring file (+ 1 (length dir))))))
 
   (it "returns the namespace matching the given string path"
     (expect (cider-expected-ns "/a/foo/bar/baz_utils.clj") :to-equal