New tests and updated docs around validation pipelining

.gitignore

@@ -8,3 +8,4 @@ pom.xml
 .lein-deps-sum
 .lein-failures
 .lein-plugins
+.lein-repl-history

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.2.3 (UNRELEASED)
 
 - Validator sets can now be used at the top level call to `validate` and `valid?`.
+- Added tested and a doc section around validation pipelining. It was an undocumented invariant. See discussion [here](https://github.com/leonardoborges/bouncer/pull/4). 
 
 ## 0.2.2 (16/01/2013)
 

README.md

@@ -4,14 +4,15 @@ A validation DSL for Clojure apps
 
 ## Table of Contents
 
-* [API Docs](http://leonardoborges.github.com/bouncer/)
+* [Annotated Source](http://leonardoborges.github.com/bouncer/)
 * [Motivation](#motivation)
 * [Setup](#setup)
 * [Usage](#usage)
     * [Basic validations](#basic-validations)
     * [Validating nested maps](#validating-nested-maps)
     * [Multiple validation errors](#multiple-validation-errors)
     * [Validating collections](#validating-collections)
+    * [Validation pipelining](#validation-pipelining)    
 * [Composability: validator sets](#composability-validator-sets)
 * [Customization support](#customization-support)
     * [Custom validators using arbitrary functions](#custom-validations-using-arbitrary-functions)
@@ -184,6 +185,21 @@ Let's see it in action:
 
 All we need to do is provide a predicate function to `every`. It will be invoked for every item in the collection, making sure they all pass.
 
+### Validation pipelining
+
+Note that if a map if pipelined through multiple validators, bouncer will leave it's errors map untouched and simply add new validation errors to it:
+
+```clojure
+(-> {:age "NaN"}
+    (core/validate :name v/required)
+    second
+    (core/validate :age v/number)
+    second
+    ::core/errors)
+
+;; {:age ("age must be a number"), :name ("name must be present")}
+```
+
 ## Composability: validator sets
 
 If you find yourself repeating a set of validators over and over, chances are you will want to group and compose them somehow. The macro `bouncer.validators/defvalidatorset` does just that:

project.clj

@@ -8,4 +8,5 @@
   :plugins [[lein-marginalia "0.7.1"]]
   :profiles {:1.3 {:dependencies [[org.clojure/clojure "1.3.0"]]}
              :1.4 {:dependencies [[org.clojure/clojure "1.4.0"]]}
-             :1.5 {:dependencies [[org.clojure/clojure "1.5.0-RC1"]]}})
+             :1.5 {:dependencies [[org.clojure/clojure "1.5.0"]]}}
+  :aliases {"all-tests" ["with-profile" "1.3:1.4:1.5" "test"]})

test/bouncer/core_test.clj

@@ -232,3 +232,15 @@
                                    :dob v/number
                                    [:passport :number] v/positive 
                                    [:address :past] (v/every #(not (nil? (:country %)))))))))))
+
+
+(deftest pipelining-validations
+  (testing "should preserve the existing errors map if there is one"
+    (let [validation-errors (-> {:age "NaN"}
+                            (core/validate :name v/required)
+                            second
+                            (core/validate :age v/number)
+                            second
+                            ::core/errors)]
+      (is (= 2
+             (count (select-keys validation-errors [:age :name])))))))