log with clojure.tools.logging if it's installed. Run tests with and without the c.t.l dependency. Fixes #172

Author: ikitommi

project.clj

@@ -30,7 +30,6 @@
                              [lein-ring "0.9.7"]
                              [funcool/codeina "0.3.0"]]
                    :dependencies [[org.clojure/clojure "1.7.0"]
-                                  [org.clojure/tools.logging "0.3.1"]
                                   [peridot "0.4.1"]
                                   [javax.servlet/servlet-api "2.5"]
                                   [midje "1.8.2"]
@@ -44,14 +43,15 @@
                           :reload-paths ["src" "examples/src"]}
                    :source-paths ["examples/src" "examples/dev-src"]
                    :main examples.server}
+             :logging {:dependencies [[org.clojure/tools.logging "0.3.1"]]}
              :1.8 {:dependencies [[org.clojure/clojure "1.8.0-RC2"]]}}
   :eastwood {:namespaces [:source-paths]
              :add-linters [:unused-namespaces]}
   :codeina {:sources ["src"]
             :target "gh-pages/doc"
             :src-dir-uri "http://github.com/metosin/compojure-api/blob/master/"
             :src-linenum-anchor-prefix "L"}
-  :aliases {"all" ["with-profile" "dev:dev,1.8"]
+  :aliases {"all" ["with-profile" "dev:dev,logging:dev,1.8"]
             "start-thingie" ["run"]
             "aot-uberjar" ["with-profile" "uberjar" "do" "clean," "ring" "uberjar"]
             "test-ancient" ["midje"]

src/compojure/api/exception.clj

@@ -1,6 +1,7 @@
 (ns compojure.api.exception
   (:require [ring.util.http-response :refer [internal-server-error bad-request]]
             [clojure.walk :refer [postwalk]]
+            [compojure.api.logging :as log]
             [schema.utils :as su])
   (:import [schema.utils ValidationError NamedError]
            [com.fasterxml.jackson.core JsonParseException]
@@ -11,12 +12,12 @@
 ;;
 
 (defn safe-handler
-  "Prints stacktrace to console and returns safe error response.
+  "Writes :error to log with the exception message & stacktrace.
 
    Error response only contains class of the Exception so that it won't accidentally
    expose secret details."
   [^Exception e _ _]
-  (.printStackTrace e)
+  (log/log! :error e (.getMessage e))
   (internal-server-error {:type "unknown-exception"
                           :class (.getName (.getClass e))}))
 

src/compojure/api/logging.clj

@@ -1,21 +1,20 @@
-(ns compojure.api.logging)
+(ns compojure.api.logging
+  (:require [clojure.string :as str]))
 
-(defn resolve-logger []
-  (if (find-ns 'clojure.tools.logging)
-    (do
-      (require 'clojure.tools.logging)
-      (fn [level x]
-        (clojure.tools.logging/spy level x)))
-    (fn [level x & more]
-      (let [log (fn [level more]
-                  (println (.toUpperCase (name level)) (apply str more)))]
-        (if (instance? Throwable x)
-          (do
-            (log level (cons (.getMessage x) more))
-            (.printStackTrace x))
-          (log level (cons x more)))))))
+;; default to console logging
+(defn log! [level x & more]
+  (let [log (fn [level more] (println (.toUpperCase (name level)) (str/join " - " more)))]
+    (if (instance? Throwable x)
+      (do
+        (log level more)
+        (.printStackTrace x))
+      (log level (into [x] more)))))
 
-(def log (resolve-logger))
-
-(comment
-  (log :info (RuntimeException. "kosh")))
+;; use c.t.l logging if available
+(if (find-ns 'clojure.tools.logging)
+  (eval
+    `(do
+       (require 'clojure.tools.logging)
+       (defmacro ~'log! [& ~'args]
+         `(do
+            (clojure.tools.logging/log ~@~'args))))))

test/compojure/api/middleware_test.clj

@@ -3,7 +3,21 @@
             [midje.sweet :refer :all]
             [ring.util.http-response :refer [ok]]
             [ring.util.http-status :as status]
-            ring.util.test))
+            ring.util.test)
+  (:import [java.io PrintStream ByteArrayOutputStream]))
+
+(defmacro without-err
+  "Evaluates exprs in a context in which *err* is bound to a fresh
+  StringWriter.  Returns the string created by any nested printing
+  calls."
+  [& body]
+  `(let [s# (PrintStream. (ByteArrayOutputStream.))
+         err# (System/err)]
+     (System/setErr s#)
+     (try
+       ~@body
+       (finally
+         (System/setErr err#)))))
 
 (facts serializable?
   (tabular
@@ -25,14 +39,14 @@
     (ring.util.test/string-input-stream "foobar") false false))
 
 (facts "wrap-exceptions"
-  (let [exception (proxy [RuntimeException] [] (printStackTrace []))
-        exception-class (.getName (.getClass exception))
-        failure (fn [_] (throw exception))
-        success (fn [_] (ok "SUCCESS"))
-        request irrelevant]
+  (with-out-str
+    (without-err
+      (let [exception (RuntimeException. "kosh")
+            exception-class (.getName (.getClass exception))
+            failure (fn [_] (throw exception))]
 
-    (fact "converts exceptions into safe internal server errors"
-      ((wrap-exceptions failure (:handlers (:exceptions api-middleware-defaults))) request)
-      => (contains {:status status/internal-server-error
-                    :body (contains {:class exception-class
-                                     :type "unknown-exception"})}))))
+        (fact "converts exceptions into safe internal server errors"
+          ((wrap-exceptions failure (:handlers (:exceptions api-middleware-defaults))) ..request..)
+          => (contains {:status status/internal-server-error
+                        :body (contains {:class exception-class
+                                         :type "unknown-exception"})}))))))