Can fake functions in other namespaces (Wilkes Joiner)

CONTRIBUTORS.md

@@ -1 +1,2 @@
 * Brian Marick
+* Wilkes Joiner

HISTORY.md

@@ -0,0 +1,3 @@
+= 0.2.0
+
+* Can fake functions from other namespaces. (Wilkes Joiner)

examples/semi-sweet-examples/lein-expected-output

@@ -11,7 +11,7 @@
      [null] FAIL at (core_test.clj:40)
      [null] Actual result did not pass expected function.
      [null] expected function: (exactly odd?)
-     [null]     actual result: #<core$even_QMARK___4680 clojure.core$even_QMARK___4680@7c33788d>
+     [null]     actual result: #<core$even_QMARK___4680 clojure.core$even_QMARK___4680@c163956>
      [null] ^^^^ The previous failure was expected ^^^^
      [null] FAIL at (core_test.clj:51)
      [null] Actual result did not pass expected function.
@@ -22,9 +22,9 @@
      [null] This expectation was never satisfied:
      [null] (first-fake 3) should be called at least once.
      [null] ^^^^ The previous failure was expected ^^^^
-     [null] Ran 9 tests containing 10 assertions.
+     [null] Ran 10 tests containing 12 assertions.
      [null] 5 failures, 0 errors.
      [null] --------------------
      [null] Total:
-     [null] Ran 9 tests containing 10 assertions.
+     [null] Ran 10 tests containing 12 assertions.
      [null] 5 failures, 0 errors.

examples/semi-sweet-examples/project.clj

@@ -1,7 +1,7 @@
-(defproject semi-sweet-simple "0.2.0"
+(defproject semi-sweet-simple "0.3.0"
   :description "An example of using Midje semi-sweet mocking"
   :dependencies [[org.clojure/clojure "1.1.0"]
                  [org.clojure/clojure-contrib "1.1.0"]]
-  :dev-dependencies [[midje "0.1.1"]]
+  :dev-dependencies [[midje "0.2.0"]]
 )
 

examples/semi-sweet-examples/run

@@ -1,2 +1,2 @@
 cd test
-java -cp ../lib/clojure-1.1.0.jar:../lib/clojure-contrib-1.1.0.jar:../lib/midje-0.1.1.jar clojure.main -i semi_sweet_simple/core_test.clj -e '(ns semi-sweet-simple.core-test)(run-tests)'
+java -cp ../lib/clojure-1.1.0.jar:../lib/clojure-contrib-1.1.0.jar:../lib/midje-0.2.0.jar clojure.main -i semi_sweet_simple/core_test.clj -e '(ns semi-sweet-simple.core-test)(run-tests)'

examples/semi-sweet-examples/run-expected-output

@@ -15,7 +15,7 @@ expected function: odd?
 FAIL at (core_test.clj:40)
 Actual result did not pass expected function.
 expected function: (exactly odd?)
-    actual result: #<core$even_QMARK___4680 clojure.core$even_QMARK___4680@19e09a4>
+    actual result: #<core$even_QMARK___4680 clojure.core$even_QMARK___4680@1dfd868>
 ^^^^ The previous failure was expected ^^^^
 
 FAIL at (core_test.clj:51)
@@ -29,6 +29,6 @@ This expectation was never satisfied:
 (first-fake 3) should be called at least once.
 ^^^^ The previous failure was expected ^^^^
 
-Ran 9 tests containing 10 assertions.
+Ran 10 tests containing 12 assertions.
 5 failures, 0 errors.
-{:type :summary, :test 9, :pass 5, :fail 5, :error 0}
+{:type :summary, :test 10, :pass 7, :fail 5, :error 0}

examples/semi-sweet-examples/test/semi_sweet_simple/core_test.clj

@@ -117,19 +117,30 @@
 ;; for that. If you do, let me know.
 
 
-;; Right now, you can't fake a function outside the current
-;; namespace. There's a saying from the OO world: "don't mock objects
-;; you don't own", so maybe this limitation is OK. If you want it, let
-;; me know, but I'm not sure it's possible.
-(comment 
-    (defn function-under-test-5 [arg]
-      (inc arg))
-
-    (deftest example-of-mocking-functions-from-another-namespace
-      (expect (function-under-test-5 1) => 5
-   	   (fake (clojure.core/inc 1) => 5)))
+;; You can fake a function outside the current namespace. Suppose we 
+;; have a function that operates on two sets. We want to override 
+;; clojure.set/intersection so that our tests can only talk about properties
+;; of tests, rather than have to laboriously construct actual sets with those
+;; properties. So we pass in descriptive strings and fake out intersection.
+;;
+;; There is (will be) more support for this style in midje.sweet.
+
+(use 'clojure.set)
+(defn set-handler [set1 set2]
+  (if (empty? (intersection set1 set2))
+    set1
+    (intersection set1 set2)))
+
+(deftest example-of-faking-function-from-another-namespace
+  "For disjoint sets, return the first."
+  (expect (set-handler "some set" "some disjoint set") => "some set"
+	  (fake (intersection "some set" "some disjoint set") => #{}))
+  "For overlapping sets, return the intersection"
+  (expect (set-handler "set" "overlapping set") => #{"intersection"}
+	  (fake (intersection "set" "overlapping set") => #{"intersection"}))
 )
 
+
 ;; My development style is "programming by wishful thinking"
 ;; (Sussman). Suppose I'm writing function (quux). If I hit anything
 ;; hard, I say "I really really believe there's already a function
@@ -162,5 +173,6 @@
   (example-of-a-simple-fake-failure)
   (example-of-multiple-faked-functions)
   (example-of-interesting-functional-args)
+  (example-of-faking-function-from-another-namespace)
 )
 

project.clj

@@ -1,4 +1,4 @@
-(defproject midje "0.1.1"
+(defproject midje "0.2.0"
   :description "A mock/stubbing library for Clojure"
   :dependencies [[org.clojure/clojure "1.1.0"]
                  [org.clojure/clojure-contrib "1.1.0"]])

test/midje/semi_sweet_test.clj

@@ -140,3 +140,18 @@
   (let [myfun (fn [x] (list x))]
     (expect (myfun 1) => :list-called
             (fake (list 1) => :list-called))))
+
+(use 'clojure.set)
+(defn set-handler [set1 set2]
+  (if (empty? (intersection set1 set2))
+    set1
+    (intersection set1 set2)))
+
+(deftest fake-function-from-other-namespace-used-in-var
+  (expect (set-handler 'set 'disjoint-set) => 'set
+	  (fake (intersection 'set 'disjoint-set) => #{}))
+  (expect (set-handler 'set 'overlapping-set) => #{'intersection}
+	  (fake (intersection 'set 'overlapping-set) => #{'intersection}))
+)
+
+