Add ns-path op

This op returns the file path to the file containing some ns on classpath.

The new op is meant to be the basis for cider-find-ns

README.md

@@ -104,7 +104,7 @@ Middleware        | Op(s)      | Description
 `wrap-info`       | `info/eldoc` | File/line, arglists, docstrings and other metadata for vars.
 `wrap-inspect`    |`inspect-(start/refresh/pop/push/reset)` | Inspect a Clojure expression.
 `wrap-macroexpand`| `macroexpand/macroexpand-1/macroexpand-all` | Macroexpand a Clojure form.
-`wrap-ns`         | `ns-list/ns-vars` | Namespace browsing.
+`wrap-ns`         | `ns-list/ns-vars/ns-path` | Namespace browsing.
 `wrap-pprint`     | | Adds pretty-printing support to code evaluation. It also installs a dummy `pprint-middleware` op. Thus `wrap-pprint` is discoverable through the `describe` op.
 `wrap-refresh`    | `refresh/refresh-all` | Code reloading.
 `wrap-resource`   | `resource` | Return resource path.

src/cider/nrepl/middleware/ns.clj

@@ -1,9 +1,16 @@
 (ns cider.nrepl.middleware.ns
-  (:require [clojure.tools.nrepl.transport :as transport]
-            [clojure.tools.nrepl.middleware :refer [set-descriptor!]]
-            [clojure.tools.nrepl.misc :refer [response-for]]
-            [cider.nrepl.middleware.util.cljs :as cljs]
-            [cljs-tooling.util.analysis :as cljs-analysis]))
+  (:require [cider.nrepl.middleware.util.cljs :as cljs]
+            [cljs-tooling.util.analysis :as cljs-analysis]
+            [clojure.java.classpath :as cp]
+            [clojure.java.io :as io]
+            [clojure.tools.namespace
+             [file :refer [read-file-ns-decl]]
+             [find :refer [clojure-sources-in-jar find-clojure-sources-in-dir]]]
+            [clojure.tools.nrepl
+             [middleware :refer [set-descriptor!]]
+             [misc :refer [response-for]]
+             [transport :as transport]])
+  (:import java.util.jar.JarFile))
 
 (defn ns-list-clj []
   (->> (all-ns)
@@ -51,13 +58,50 @@
   (transport/send transport (response-for msg :ns-vars (ns-vars msg)))
   (transport/send transport (response-for msg :status :done)))
 
+(defn- jar-file?
+  "Returns true if file is a normal file with a .jar or .JAR extension."
+  [f]
+  (let [file (io/file f)]
+    (and (.isFile file)
+         (.endsWith (.. file getName toLowerCase) ".jar"))))
+
+(defn- get-clojure-sources-in-jar
+  [^JarFile jar]
+  (let [path-to-jar (.getName jar)]
+    (map #(str "jar:file:" path-to-jar "!/" %) (clojure-sources-in-jar jar))))
+
+(defn- all-clj-files-on-cp []
+  (let [dirs-on-cp (filter #(.isDirectory %) (cp/classpath))
+        jars-on-cp (map #(JarFile. %) (filter jar-file? (cp/classpath)))]
+    (concat (->> dirs-on-cp
+                 (mapcat find-clojure-sources-in-dir)
+                 (map #(.getAbsolutePath %)))
+            (mapcat get-clojure-sources-in-jar jars-on-cp))))
+
+(defn- ns-path
+  [{:keys [ns]}]
+  (let [ns (symbol ns)]
+    (loop [paths (all-clj-files-on-cp)]
+      (when (seq paths)
+        (let [file-ns (second (read-file-ns-decl (first paths)))]
+          (if (= file-ns ns)
+            (first paths)
+            (recur (rest paths))))))))
+
+(defn- ns-path-reply
+  [{:keys [transport] :as msg}]
+  (when-let [path (ns-path msg)]
+    (transport/send transport (response-for msg :path (ns-path msg))))
+  (transport/send transport (response-for msg :status :done)))
+
 (defn wrap-ns
   "Middleware that provides ns listing/browsing functionality."
   [handler]
   (fn [{:keys [op] :as msg}]
     (case op
       "ns-list" (ns-list-reply msg)
       "ns-vars" (ns-vars-reply msg)
+      "ns-path" (ns-path-reply msg)
       (handler msg))))
 
 (set-descriptor!
@@ -69,5 +113,9 @@
      :returns {"status" "done"}}
     "ns-vars"
     {:doc "Returns a sorted list of all vars in a namespace."
-     :requires {"ns" "The namespace to browse"}
-     :returns {"status" "done"}}}}))
+     :requires {"ns" "The namespace to browse."}
+     :returns {"status" "done"}}
+    "ns-path"
+    {:doc "Returns the path to the file containing ns."
+     :requires {"ns" "The namespace to find."}
+     :return {"status" "done" "path" "The path to the file containing ns."}}}}))

test/clj/cider/nrepl/middleware/ns_test.clj

@@ -25,3 +25,11 @@
                                             :ns "clojure.walk"}))]
     (is (sequential? ns-vars))
     (is (every? string? ns-vars))))
+
+(deftest ns-path-integration-test
+  (let [ns-path (:path (session/message {:op "ns-path"
+                                         :ns "cider.nrepl.middleware.ns"}))
+        core-path (:path (session/message {:op "ns-path"
+                                           :ns "clojure.core"}))]
+    (is (.endsWith ns-path "cider/nrepl/middleware/ns.clj"))
+    (is (.endsWith core-path "clojure/core.clj"))))