[Fix #1061] Add cider-find-ns

Provide a completing read of available namespaces and jump to the file
containing its definition.

Author: expez

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### New features
 
+* [#1061](https://github.com/clojure-emacs/cider/issues/1061) New command `cider-find-ns`, bound to <kbd>c-c c-.</kbd>, which prompts for an ns and jumps to the corresponding source file.
 * [#1019](https://github.com/clojure-emacs/cider/pull/1019): New file, cider-debug.el.
   Provides a new command, `cider-debug-defun-at-point`, bound to <kbd>C-u C-M-x</kbd>.
   Interactively debug top-level clojure forms.

README.md

@@ -763,6 +763,7 @@ Keyboard shortcut                    | Description
 <kbd>C-c C-t</kbd>                   | Show the test report buffer.
 <kbd>M-.</kbd>                       | Jump to the definition of a symbol.  If invoked with a prefix argument, or no symbol is found at point, prompt for a symbol.
 <kbd>C-c M-.</kbd>                   | Jump to the resource referenced by the string at point.
+<kbd>C-c C-.</kbd>                   | Jump to some namespace on the classpath.
 <kbd>M-,</kbd>                       | Return to your pre-jump location.
 <kbd>M-TAB</kbd>                     | Complete the symbol at point.
 <kbd>C-c C-d g</kbd>                 | Lookup symbol in Grimoire.
@@ -793,6 +794,7 @@ Keyboard shortcut                    | Description
 <kbd>C-c C-z</kbd> | Switch to the previous Clojure buffer. This complements <kbd>C-c C-z</kbd> used in cider-mode.
 <kbd>C-c M-i</kbd> | Inspect expression. Will act on expression at point if present.
 <kbd>C-c M-n</kbd> | Select a namespace and switch to it.
+<kbd>C-c C-.</kbd> | Jump to some namespace on the classpath.
 <kbd>C-c M-t v</kbd> | Toggle var tracing.
 <kbd>C-c M-t n</kbd> | Toggle namespace tracing.
 

cider-interaction.el

@@ -214,7 +214,7 @@ if the candidate is not namespace-qualified."
 (defvar cider-required-nrepl-ops
   '("apropos" "classpath" "complete" "eldoc" "format-code" "format-edn" "info"
     "inspect-pop" "inspect-push" "inspect-refresh"
-    "macroexpand" "ns-list" "ns-vars" "refresh"
+    "macroexpand" "ns-list" "ns-vars" "ns-path" "refresh"
     "resource" "stacktrace" "toggle-trace-var" "toggle-trace-ns" "undef")
   "A list of nREPL ops required by CIDER to function properly.
 
@@ -924,6 +924,31 @@ thing at point."
                  #'cider--find-var-other-window
                #'cider--find-var))))
 
+(defun cider-sync-request:ns-path (ns)
+  "Get the path to the file containing NS."
+  (-> (list "op" "ns-path"
+            "ns" ns)
+      nrepl-send-sync-request
+      (nrepl-dict-get "path")))
+
+(defun cider--find-ns (ns &optional other-window)
+  (-if-let (path (cider-sync-request:ns-path ns))
+      (cider-jump-to (cider-find-file path) nil other-window)
+    (error "Can't find %s" ns)))
+
+(defun cider-find-ns (&optional arg ns)
+  "Find the file containing NS.
+
+A prefix of `-` or a double prefix argument causes
+the results to be displayed in a different window."
+  (interactive "P")
+  (cider-ensure-op-supported "ns-path")
+  (if ns
+      (cider--find-ns ns)
+    (let* ((namespaces (cider-sync-request:ns-list))
+           (ns (completing-read "Find namespace: " namespaces)))
+      (cider--find-ns ns (cider--open-other-window-p arg)))))
+
 (define-obsolete-function-alias 'cider-jump-to-resource 'cider-find-resource "0.9.0")
 (define-obsolete-function-alias 'cider-jump-to-var 'cider-find-var "0.9.0")
 (defalias 'cider-jump-back 'pop-tag-mark)

cider-mode.el

@@ -55,6 +55,7 @@ entirely."
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "C-c C-d") #'cider-doc-map)
     (define-key map (kbd "M-.") #'cider-find-var)
+    (define-key map (kbd "C-c C-.") #'cider-find-ns)
     (define-key map (kbd "M-,") #'cider-jump-back)
     (define-key map (kbd "C-c M-.") #'cider-find-resource)
     (define-key map (kbd "M-TAB") #'complete-symbol)

cider-repl.el

@@ -1003,6 +1003,7 @@ constructs."
     (set-keymap-parent map clojure-mode-map)
     (define-key map (kbd "C-c C-d") 'cider-doc-map)
     (define-key map (kbd "M-.") 'cider-find-var)
+    (define-key map (kbd "C-c C-.") #'cider-find-ns)
     (define-key map (kbd "M-,") 'cider-jump-back)
     (define-key map (kbd "C-c M-.") 'cider-find-resource)
     (define-key map (kbd "RET") 'cider-repl-return)