issue-2: support mocking private functions

Author: zhming0

README.md

@@ -19,7 +19,9 @@ Temporarily redefines `var` while executing `body`.
 If the right-hand side of a spec is a value, then it will create a function constantly returning the value (stub).
 If the right-hand side of a spec is a function, then the var-symbol will temporarily be replaced by the function.
 
-### Example 
+### Features & Example 
+
+#### Track mock's invocation history
 
 ```clojure
 
@@ -43,6 +45,22 @@ If the right-hand side of a spec is a function, then the var-symbol will tempora
 
 ```
 
+#### Mock private functions with ease
+
+```clojure
+(ns ns-a)
+(defn- g [] true)
+(defn f [a] (g))
+
+(ns ns-b)
+(deftest mock-private-test
+  (with-mock [#'ns-a/g "baz"]
+    (is (= (f "foo") "baz"))))
+
+```
+
+(Note: generally, it's not a good idea to mock private functions)
+
 ## License
 
 Copyright © 2017 Ming

project.clj

@@ -1,4 +1,4 @@
-(defproject mock-clj "0.1.0"
+(defproject mock-clj "0.2.0"
   :description "A minimalist & non-invasive API for mocking in Clojure"
   :url "https://github.com/zhming0/mock-clj"
   :license {:name "Eclipse Public License"

src/mock_clj/core.clj

@@ -5,30 +5,49 @@
   Internal functions - ignore these
 """
 
+; Check if input is like '(var x) or #'x
+(defn- var-symbol? [v] 
+  (and
+    (seq? v)
+    (= 2 (count v))
+    (= (first v) 'var)))
+
+(defn- try-strip-var [v]
+  (if (var-symbol? v)
+    (second v)
+    v))
+
 (defmacro make-mock 
-  ([m] `(make-mock ~m nil))
-  ([m stub] 
-   `(with-meta
-      (fn [& ~'args] 
-        (swap! (-> ~m meta :args) conj ~'args)
-        ; If stub is a function, execute it
-        (if (fn? ~stub) 
-          (apply ~stub ~'args)
-          ~stub))
-      {:args (atom [])})))
-
-(defn gen-redefs [[m stub & spec]]
-  (into 
-    [m `(make-mock ~m ~stub)]
-    (when spec
-      (gen-redefs spec))))
+  ([] `(make-mock nil))
+  ([stub] 
+   `(let [~'state (atom [])]
+     (with-meta
+       (fn [& ~'args] 
+         (swap! ~'state conj ~'args)
+         ; If stub is a function, execute it
+         (if (fn? ~stub) 
+           (apply ~stub ~'args)
+           ~stub))
+       {:args ~'state}))))
+
+(defn- gen-redefs [[m stub & spec]]
+  (let [sm (try-strip-var m)]
+   (into 
+     [sm `(make-mock ~stub)]
+     (when spec
+       (gen-redefs spec)))))
+
+(defn- if-var->obj [m]
+  (if (var? m)
+    (deref m)
+    m))
 
 """
 ------------------------------------
   APIs
 """
 
-(defn calls [m] @(-> m meta :args))
+(defn calls [m] @(-> m if-var->obj meta :args))
 
 (defn last-call [m] (last (calls m)))
 

test/mock_clj/core_test.clj

@@ -1,6 +1,7 @@
 (ns mock-clj.core-test
   (:require [clojure.test :refer :all]
-            [mock-clj.core :refer :all]))
+            [mock-clj.core :refer :all]
+            [mock-clj.sample-private-ns]))
 
 (defn foo [a & rst] 
   (str "foo" a))
@@ -66,3 +67,9 @@
     (is (called? foo))
     (reset-calls! foo)
     (is (not (called? foo)))))
+
+(deftest private-fn-test
+  (with-mock [mock-clj.sample-private-ns/private-fn (constantly "ok")]
+    (= "ok" (#'mock-clj.sample-private-ns/private-fn 2))
+    (is (called? #'mock-clj.sample-private-ns/private-fn))
+    (is (= (last-call #'mock-clj.sample-private-ns/private-fn) [2]))))

test/mock_clj/sample_private_ns.clj

@@ -0,0 +1,3 @@
+(ns mock-clj.sample-private-ns)
+
+(defn- private-fn [a] "bar")