Add configuration file to CLI

The cljfmt.main function searches the current directory and all parent
directories for a configuration file named either .cljfmt.edn or
.cljfmt.clj. The first configuration file found is used.

Command line options override the options in the configuration file,
except for the indents, which are merged with the defaults.

README.md

@@ -101,13 +101,21 @@ clojure -Sdeps '{:deps {cljfmt {:mvn/version "0.9.0"}}}' \
 
 ## Configuration
 
+### Leiningen
 You can configure lein-cljfmt by adding a `:cljfmt` map to your
 project:
 
 ```clojure
 :cljfmt {}
 ```
 
+### Command line
+You can configure `cljfmt` by placing a `.cljfmt.edn` or `.cljfmt.clj`
+file in the directory where you run the command, or any parent
+directory. The first file in the hierarchy will be used, files in
+higher up parent directories are ignored.
+
+### Rules
 cljfmt has several different formatting rules, and these can be
 selectively enabled or disabled:
 

cljfmt/src/cljfmt/main.clj

@@ -1,12 +1,12 @@
 (ns cljfmt.main
   "Functionality to apply formatting to a given project."
   (:require [cljfmt.core :as cljfmt]
-            [clojure.string :as str]
+            [cljfmt.diff :as diff]
             [clojure.edn :as edn]
             [clojure.java.io :as io]
             [clojure.stacktrace :as st]
-            [clojure.tools.cli :as cli]
-            [cljfmt.diff :as diff])
+            [clojure.string :as str]
+            [clojure.tools.cli :as cli])
   (:gen-class))
 
 (defn- abort [& msg]
@@ -154,68 +154,89 @@
       (read-string contents)
       (edn/read-string contents))))
 
-(def default-options
+(defn- parent-dirs [^String root]
+  (->> (.getAbsoluteFile (io/file root))
+       (iterate #(.getParentFile ^java.io.File %))
+       (take-while some?)))
+
+(defn- find-file-in-dir ^java.io.File [^java.io.File dir ^String name]
+  (let [f (io/file dir name)]
+    (when (.exists f) f)))
+
+(defn- find-config-file-in-dir ^java.io.File [^java.io.File dir]
+  (or (find-file-in-dir dir ".cljfmt.edn")
+      (find-file-in-dir dir ".cljfmt.clj")))
+
+(defn- load-configuration []
+  (some->> (parent-dirs "")
+           (some find-config-file-in-dir)
+           (#(.getPath ^java.io.File %))
+           cli-file-reader))
+
+(defn- load-default-options []
   (merge cljfmt/default-options
          {:project-root "."
           :file-pattern #"\.clj[csx]?$"
           :ansi?        true
-          :parallel?    false}))
+          :parallel?    false}
+         (load-configuration)))
 
-(defn merge-default-options [options]
-  (-> (merge default-options options)
-      (assoc :indents (merge (:indents default-options)
+(defn merge-default-options [defaults options]
+  (-> (merge defaults options)
+      (assoc :indents (merge (:indents defaults)
                              (:indents options {})))))
 
 (def default-paths ["src" "test" "project.clj"])
 
-(def ^:private cli-options
+(defn- cli-options [defaults]
   [[nil "--help"]
    [nil "--parallel"
     :id :parallel?]
    [nil "--project-root PROJECT_ROOT"
-    :default (:project-root default-options)]
+    :default (:project-root defaults)]
    [nil "--file-pattern FILE_PATTERN"
-    :default (:file-pattern default-options)
+    :default (:file-pattern defaults)
     :parse-fn re-pattern]
    [nil "--indents INDENTS_PATH"
     :parse-fn cli-file-reader]
    [nil "--alias-map ALIAS_MAP_PATH"
     :parse-fn cli-file-reader]
    [nil "--[no-]ansi"
-    :default (:ansi? default-options)
+    :default (:ansi? defaults)
     :id :ansi?]
    [nil "--[no-]indentation"
-    :default (:indentation? cljfmt/default-options)
+    :default (:indentation? defaults)
     :id :indentation?]
    [nil "--[no-]remove-multiple-non-indenting-spaces"
-    :default (:remove-multiple-non-indenting-spaces? cljfmt/default-options)
+    :default (:remove-multiple-non-indenting-spaces? defaults)
     :id :remove-multiple-non-indenting-spaces?]
    [nil "--[no-]remove-surrounding-whitespace"
-    :default (:remove-surrounding-whitespace? cljfmt/default-options)
+    :default (:remove-surrounding-whitespace? defaults)
     :id :remove-surrounding-whitespace?]
    [nil "--[no-]remove-trailing-whitespace"
-    :default (:remove-trailing-whitespace? cljfmt/default-options)
+    :default (:remove-trailing-whitespace? defaults)
     :id :remove-trailing-whitespace?]
    [nil "--[no-]insert-missing-whitespace"
-    :default (:insert-missing-whitespace? cljfmt/default-options)
+    :default (:insert-missing-whitespace? defaults)
     :id :insert-missing-whitespace?]
    [nil "--[no-]remove-consecutive-blank-lines"
-    :default (:remove-consecutive-blank-lines? cljfmt/default-options)
+    :default (:remove-consecutive-blank-lines? defaults)
     :id :remove-consecutive-blank-lines?]
    [nil "--[no-]split-keypairs-over-multiple-lines"
-    :default (:split-keypairs-over-multiple-lines? cljfmt/default-options)
+    :default (:split-keypairs-over-multiple-lines? defaults)
     :id :split-keypairs-over-multiple-lines?]
    [nil "--[no-]sort-ns-references"
-    :default (:sort-ns-references? cljfmt/default-options)
+    :default (:sort-ns-references? defaults)
     :id :sort-ns-references?]])
 
 (defn- file-exists? [path]
   (.exists (io/as-file path)))
 
 (defn -main [& args]
-  (let [parsed-opts   (cli/parse-opts args cli-options)
+  (let [defaults      (load-default-options)
+        parsed-opts   (cli/parse-opts args (cli-options defaults))
         [cmd & paths] (:arguments parsed-opts)
-        options       (merge-default-options (:options parsed-opts))
+        options       (merge-default-options defaults (:options parsed-opts))
         paths         (or (seq paths) (filter file-exists? default-paths))]
     (if (:errors parsed-opts)
       (abort (:errors parsed-opts))