Feature/validate xref (#39)

* not needed anymore

* add more documentation

* fix markup

* implement xref validation

src/crucible/core.clj

@@ -1,6 +1,7 @@
 (ns crucible.core
   "Commonly used template construction functions"
   (:require [clojure.spec :as s]
+            [clojure.walk :as walk]
             [crucible.values :as v]
             [crucible.parameters :as p]
             [crucible.resources :as r]
@@ -17,6 +18,18 @@
 (s/def ::template (s/cat :description ::description
                          :elements (s/nilable (s/map-of keyword? ::element))))
 
+(defn validate [template]
+  (walk/prewalk
+   (fn [x]
+     (cond
+       (and (vector? x)
+            (= 2 (count x))
+            (= ::v/ref (first x))) (if-not (contains? (:elements template) (second x))
+                                     (throw (ex-info "Missing reference" {:ref (second x)}))
+                                     x)
+       :else x))
+   template))
+
 (defn template
   "Make a template structure with the given description and elements"
   [description & {:as elements}]
@@ -25,7 +38,9 @@
         parsed (s/conform spec input)]
     (if (= parsed ::s/invalid)
       (throw (ex-info "Invalid input" (s/explain-data spec input)))
-      (with-meta parsed {::template true}))))
+      (-> parsed
+          validate
+          (with-meta {::template true})))))
 
 (defn parameter
   "Make a template parameter element"

src/crucible/encoding.clj

@@ -8,9 +8,6 @@
 (defmethod ->key :aws-template-format-version [_]
   "AWSTemplateFormatVersion")
 
-(defn validate-element [_ element]
-  element)
-
 (defmulti rewrite-element-data (fn [[type _]] type))
 
 (defn unqualify-keyword [kw] (-> kw name keyword))
@@ -55,7 +52,6 @@
 (defn elements->template [elements-map empty-template]
   (->> elements-map
        seq
-       (map (partial validate-element elements-map))
        (map rewrite-element)
        (reduce assemble-template empty-template)))
 

test-resources/aws/cloudwatch/alarm.json

@@ -1,6 +1,10 @@
 {
     "AWSTemplateFormatVersion" : "2010-09-09",
     "Description": "sample",
+    "Parameters": {
+        "WebServerScaleUpPolicy": {"Type": "String"},
+        "WebServerGroup": {"Type": "String"}
+    },
     "Resources": {
         "CpuAlarmHigh": {
             "Type": "AWS::CloudWatch::Alarm",

test/crucible/aws/cloudwatch_test.clj

@@ -12,6 +12,8 @@
             (cru/encode
              (cru/template
               "sample"
+              :web-server-scale-up-policy (cru/parameter)
+              :web-server-group (cru/parameter)
               :cpu-alarm-high (cw/alarm #::cw{:alarm-description "Scale-up if CPU is greater than 90% for 10 minutes"
                                               :metric-name "CPUUtilization"
                                               :namespace "AWS/EC2"

test/crucible/encoding/template_test.clj

@@ -118,20 +118,6 @@
              (template "t"
                        :my-resource (ec2/vpc {::ec2/cidr-block notification-arns}))))))))
 
-#_(deftest resource-reference-validation-test
-    (testing "reference non-existent parameter from resource property throws"
-      (is (thrown? AssertionError (make-template {:resources
-                                                  {:my-resource
-                                                   {:name "Custom::Test"
-                                                    :properties {:test [:ref :foo]}}}})))))
-
-#_(deftest references-match-template-keys
-    (testing "references in values match template keys"
-      (let [t (make-template {:parameters {:foo nil}
-                              :resources {:bar {:name "Custom::Test"
-                                                :properties {:baz [:ref :foo]}}}})]
-        (is (contains? (get t "Parameters") (get-in t ["Resources"
-                                                       "Bar"
-                                                       "Properties"
-                                                       "Baz"
-                                                       "Ref"]))))))
+(deftest resource-reference-validation-test
+  (testing "reference non-existent parameter from resource property throws"
+    (is (thrown? Exception (template "t" :my-resource (ec2/vpc {::ec2/cidr-block (xref :foo)}))))))

test/crucible/template_test.clj

@@ -7,6 +7,12 @@
             [crucible.resources :as res]
             [crucible.aws.ec2 :as ec2]))
 
+(deftest template-metadata-tag
+  (is (true? (-> "t"
+                 template
+                 meta
+                 :crucible.core/template))))
+
 (deftest minimal-template
   (is (= {:description "t"
           :elements
@@ -28,11 +34,11 @@
                                           #::ec2{:cidr-block "1.2.3.4/16"
                                                  :vpc-id
                                                  #::v{:type ::v/xref,
-                                                      :ref :foo}}}}}}
+                                                      :ref :subnet}}}}}}
          (template "t"
                    :vpc (ec2/vpc {::ec2/cidr-block "1.2.3.4/24"})
                    :subnet (ec2/subnet {::ec2/cidr-block "1.2.3.4/16"
-                                        ::ec2/vpc-id (xref :foo)})))))
+                                        ::ec2/vpc-id (xref :subnet)})))))
 
 (deftest template-with-param
   (is (= {:description "t"
@@ -48,37 +54,40 @@
                    :vpc (ec2/vpc {::ec2/cidr-block (xref :vpc-cidr)})))))
 
 (deftest template-with-output
-  (is (= {:description "t",
+  (is (= {:description "t"
           :elements
-          {:vpc-id
+          {:vpc-cidr {:type :parameter
+                      :specification #::param{:type ::param/string}}
+           :vpc-id
            {:type :output
-            :specification #::out{:description "the vpc id",
-                                  :value #::v{:type ::v/xref,
-                                              :ref :vpc}}},
+            :specification #::out{:description "the vpc id"
+                                  :value #::v{:type ::v/xref
+                                              :ref :vpc}}}
            :vpc
            {:type :resource
-            :specification #::res{:type "AWS::EC2::VPC",
+            :specification #::res{:type "AWS::EC2::VPC"
                                   :properties {::ec2/cidr-block
-                                               #::v{:type ::v/xref,
+                                               #::v{:type ::v/xref
                                                     :ref :vpc-cidr}}}}}}
          (template "t"
+                   :vpc-cidr (parameter)
                    :vpc (ec2/vpc {::ec2/cidr-block (xref :vpc-cidr)})
                    :vpc-id (output (xref :vpc) "the vpc id")))))
 
 (deftest join-fn-in-value-position
-  (is (= {:description "t",
+  (is (= {:description "t"
           :elements
           {:vpc-cidr
            {:type :parameter
-            :specification #::param{:type ::param/string}},
+            :specification #::param{:type ::param/string}}
            :vpc
            {:type :resource
-            :specification #::res{:type "AWS::EC2::VPC",
+            :specification #::res{:type "AWS::EC2::VPC"
                                   :properties
                                   {::ec2/cidr-block
-                                   #::v{:type ::v/join,
-                                        :fn-values ["foo" #::v{:type ::v/xref,
-                                                               :ref :vpc-cidr}],
+                                   #::v{:type ::v/join
+                                        :fn-values ["foo" #::v{:type ::v/xref
+                                                               :ref :vpc-cidr}]
                                         :delimiter "-"}}}}}}
          (template "t"
                    :vpc-cidr (parameter)