Update README/CHANGELOG, use find instead of first+filter

Author: plexus

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* [#251](https://github.com/clojure-emacs/refactor-nrepl/pull/251) `clean-ns` support extra message key `relative-path`, which will be used if `path` does not exist.
+
 ## 2.4.0
 
 * [#231](https://github.com/clojure-emacs/refactor-nrepl/issues/231) hotload-dependencies temporarily disabled due to java 10 issues.

README.md

@@ -161,7 +161,7 @@ The `clean-ns` op will perform the following cleanups on an ns form:
 * Use the shorthand version of metadata found if possible, and sort it
   alphabetically
 
-The `clean-ns` requires a `path` which is the path to the file containing the `ns` to be operated upon.
+The `clean-ns` requires a `path` which must be the absolute path to the file containing the `ns` to be operated upon. A client should also pass in a `relative-path`, which is the path relative to the project root, and which is used as a fallback when the `path` does not exist. (see [clj-refactor.el #380](https://github.com/clojure-emacs/clj-refactor.el/issues/380)).
 
 The return value, `ns` is the entire `(ns ..)` form in prestine condition, or `nil` if nothing was done (so the client doesn't update the timestamp on files when nothing actually needs doing).
 

src/refactor_nrepl/ns/clean_ns.clj

@@ -36,10 +36,14 @@
   (assert-no-exclude-clause (core/get-ns-component ns-form :use))
   ns-form)
 
+(defn- find
+  "Find the first element in coll that satisfies pred?"
+  [pred? coll]
+  (reduce (fn [_ x] (when (pred? x) (reduced x))) nil coll))
+
 (defn clean-ns [{:keys [path relative-path]}]
-  {:pre [(seq path) (string? path)]}
-  ;; Try first the absolute, then the relative path
-  (let [path (first (filter #(some-> % io/file .exists) [path relative-path]))]
+  (let [path (find #(and % (.exists (io/file %)))
+                   [path relative-path])]
     (assert (core/source-file? path))
     ;; Prefix notation not supported in cljs.
     ;; We also turn it off for cljc for reasons of symmetry