Add first pass at configurable components.

project.clj

@@ -17,9 +17,11 @@
             [lein-bikeshed "0.5.2"]
             [jonase/eastwood "1.4.0"]]
 
-  :dependencies [[io.logicblocks/jason "1.0.0"]
-                 [clj-commons/clj-yaml "1.0.27"]
+  :dependencies [[clj-commons/clj-yaml "1.0.27"]
+                 [com.stuartsierra/component "1.1.0"]
+                 [com.stuartsierra/dependency "1.0.0"]
                  [environ "1.2.0"]
+                 [io.logicblocks/jason "1.0.0"]
                  [medley "1.4.0"]]
 
   :profiles

src/configurati/component.clj

@@ -0,0 +1,45 @@
+(ns configurati.component
+  (:require
+   [clojure.string :as string]
+   [com.stuartsierra.component :as comp]
+   [com.stuartsierra.component.platform :as comp-platform]))
+
+(defprotocol Configurable
+  (configure [component]))
+
+(defn- attempt-configure-system [system]
+  (comp/update-system system (keys system)
+    (fn [component]
+      (if (satisfies? Configurable component)
+        (try
+          (configure component)
+          (catch Throwable t
+            (assoc component
+              ::configuration-error t)))
+        component))))
+
+(defn- collect-configuration-errors [system]
+  (reduce-kv
+    (fn [error-context key component]
+      (let [error (::configuration-error component)]
+        (if error (assoc error-context key error) error-context)))
+    nil
+    system))
+
+(defn configure-system [system]
+  (let [configured-system
+        (attempt-configure-system system)
+        component-errors
+        (collect-configuration-errors configured-system)]
+    (if component-errors
+      (throw
+        (ex-info
+          (str "Error during configuration of system "
+            (comp-platform/type-name system)
+            " in components #{"
+            (string/join " " (vec (keys component-errors)))
+            "}")
+          {:reason ::system-configuration-threw-exception
+           :system configured-system
+           :components component-errors}))
+      configured-system)))

test/configurati/component_test.clj

@@ -0,0 +1,192 @@
+(ns configurati.component-test
+  (:require
+   [clojure.test :refer [deftest is]]
+   [com.stuartsierra.component :as comp]
+   [configurati.core :as conf]
+   [configurati.component :as conf-comp]))
+
+(defrecord NonConfigurableComponent [])
+
+(defrecord ConfigurableComponent [configuration-definition configuration]
+           conf-comp/Configurable
+           (configure [component]
+             (assoc component
+               :configuration
+               (conf/resolve configuration-definition))))
+
+(defrecord DependentComponent
+  [configurable-component configuration-selector value]
+  conf-comp/Configurable
+  (configure [component]
+    (assoc component
+      :value (configuration-selector
+               (:configuration configurable-component)))))
+
+(deftest configures-single-component-system
+  (let [config-def
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-parameter :second)
+          (conf/with-source
+            (conf/map-source
+              {:first 1 :second 2 :third 3})))
+        component (map->ConfigurableComponent
+                    {:configuration-definition config-def})
+        initial-system (comp/system-map
+                         :component component)
+        configured-system (conf-comp/configure-system initial-system)]
+    (is (= {:first 1 :second 2}
+          (get-in configured-system [:component :configuration])))))
+
+(deftest configures-multi-component-system
+  (let [config-def-1
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-source {:first 1 :second 2}))
+        config-def-2
+        (conf/configuration
+          (conf/with-parameter :second)
+          (conf/with-source {:second 2 :third 3}))
+        component-1 (map->ConfigurableComponent
+                      {:configuration-definition config-def-1})
+        component-2 (map->ConfigurableComponent
+                      {:configuration-definition config-def-2})
+        initial-system (comp/system-map
+                         :component-1 component-1
+                         :component-2 component-2)
+        configured-system (conf-comp/configure-system initial-system)]
+    (is (= {:first 1}
+          (get-in configured-system [:component-1 :configuration])))
+    (is (= {:second 2}
+          (get-in configured-system [:component-2 :configuration])))))
+
+(deftest configures-dependent-component-system
+  (let [config-def
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-parameter :second)
+          (conf/with-source {:first 1 :second 2 :third 3}))
+        configurable-component
+        (map->ConfigurableComponent
+          {:configuration-definition config-def})
+        dependent-component
+        (map->DependentComponent
+          {:configuration-selector (fn [config] (:second config))})
+        initial-system
+        (comp/system-map
+          :configurable-component
+          configurable-component
+
+          :dependent-component
+          (comp/using dependent-component
+            [:configurable-component]))
+        configured-system (conf-comp/configure-system initial-system)]
+    (is (= 2 (get-in configured-system [:dependent-component :value])))))
+
+(deftest ignores-non-configurable-components
+  (let [config-def
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-source {:first 1 :second 2}))
+        configurable-component
+        (map->ConfigurableComponent
+          {:configuration-definition config-def})
+        non-configurable-component
+        (map->NonConfigurableComponent {})
+        initial-system
+        (comp/system-map
+          :configurable-component configurable-component
+          :non-configurable-component non-configurable-component)
+        configured-system (conf-comp/configure-system initial-system)]
+    (is (= {:first 1}
+          (get-in configured-system
+            [:configurable-component :configuration])))
+    (is (= non-configurable-component
+          (get configured-system :non-configurable-component)))))
+
+(deftest throws-on-resolution-failure-on-single-component
+  (let [config-def
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-parameter :second)
+          (conf/with-source
+            (conf/map-source
+              {:third 3})))
+        config-resolution-error
+        (try (conf/resolve config-def) (catch Throwable t t))
+        component (map->ConfigurableComponent
+                    {:configuration-definition config-def})
+        initial-system (comp/system-map
+                         :component component)
+        configuration-error
+        (try
+          (conf-comp/configure-system initial-system)
+          (catch Exception e e))
+        configuration-error-data
+        (ex-data configuration-error)]
+    (is (= (str "Error during configuration of system "
+             "com.stuartsierra.component.SystemMap "
+             "in components #{:component}")
+          (ex-message configuration-error)))
+    (is (= ::conf-comp/system-configuration-threw-exception
+          (:reason configuration-error-data)))
+    (is (some? (:system configuration-error-data)))
+    (is (= (ex-message config-resolution-error)
+          (ex-message (get-in configuration-error-data
+                        [:components :component]))))
+    (is (= (ex-data config-resolution-error)
+          (ex-data (get-in configuration-error-data
+                     [:components :component]))))))
+
+(deftest throws-on-resolution-failure-on-many-components
+  (let [config-def-1
+        (conf/configuration
+          (conf/with-parameter :first)
+          (conf/with-parameter :second)
+          (conf/with-source
+            (conf/map-source
+              {:third 3})))
+        config-def-2
+        (conf/configuration
+          (conf/with-parameter :second)
+          (conf/with-parameter :third)
+          (conf/with-source
+            (conf/map-source
+              {:first 1})))
+        config-resolution-error-1
+        (try (conf/resolve config-def-1) (catch Throwable t t))
+        config-resolution-error-2
+        (try (conf/resolve config-def-2) (catch Throwable t t))
+
+        component-1 (map->ConfigurableComponent
+                      {:configuration-definition config-def-1})
+        component-2 (map->ConfigurableComponent
+                      {:configuration-definition config-def-2})
+        initial-system (comp/system-map
+                         :component-1 component-1
+                         :component-2 component-2)
+        configuration-error
+        (try
+          (conf-comp/configure-system initial-system)
+          (catch Exception e e))
+        configuration-error-data
+        (ex-data configuration-error)]
+    (is (= (str "Error during configuration of system "
+             "com.stuartsierra.component.SystemMap "
+             "in components #{:component-1 :component-2}")
+          (ex-message configuration-error)))
+    (is (= ::conf-comp/system-configuration-threw-exception
+          (:reason configuration-error-data)))
+    (is (some? (:system configuration-error-data)))
+    (is (= (ex-message config-resolution-error-1)
+          (ex-message (get-in configuration-error-data
+                        [:components :component-1]))))
+    (is (= (ex-data config-resolution-error-1)
+          (ex-data (get-in configuration-error-data
+                     [:components :component-1]))))
+    (is (= (ex-message config-resolution-error-2)
+          (ex-message (get-in configuration-error-data
+                        [:components :component-2]))))
+    (is (= (ex-data config-resolution-error-2)
+          (ex-data (get-in configuration-error-data
+                     [:components :component-2]))))))