Don't let inlined functions be faked.

HISTORY.md

@@ -1,4 +1,5 @@
 1.3-alpha5
+* Prevents you from overriding functions that the compiler inlines.
 * Now works properly with aot-compilation. More properly, at least.
 * partial prerequisites
   https://github.com/marick/Midje/wiki/Partial-prerequisites

src/midje/error_handling/semi_sweet_errors.clj

@@ -8,13 +8,23 @@
     [midje.ideas.metaconstants :only [metaconstant-symbol?]]
     [midje.ideas.arrow-symbols :only [=contains=>]]))
 
+(defn- compiler-will-inline-fn? [fn]
+  (contains? (meta (resolve fn)) :inline))
+
 (defmethod validate "fake" [[_fake_ & fake-form :as form]]
   (let [funcall (first fake-form)]
     (cond (not (list? funcall))
           (user-error-report-form
             form
             "The left-hand-side of a prerequisite must look like a function call."
             (cl-format nil "`~S` doesn't." funcall))
+
+          (compiler-will-inline-fn? (first funcall))
+          (user-error-report-form
+           form
+           (cl-format nil "You cannot override the function `~S`: it is inlined by the Clojure compiler." (first funcall)))
+
+
           :else
           fake-form)))
 

test/midje/error_handling/t_semi_sweet_errors.clj

@@ -25,11 +25,6 @@
 
 ;;; Full-bore tests.
 
-(defmacro user-error-with-notes [& notes]
-  `(just (contains {:notes (just ~@notes)
-                    :type :user-error})))
-
-
 (after-silently
  (expect (+ 1 2) =>)
  (expect @reported => (user-error-with-notes

test/midje/internal_ideas/t_fakes.clj

@@ -158,6 +158,17 @@
      text => #"clojure\.core/every\?"
      text => #"interferes with.*Midje")))
 
+;; And inlined functions can't be faked
+
+(defn doubler [n] (+ n n))
+
+(after-silently
+ (fact
+   (doubler 3) => 0
+   (provided
+     (+ 3 3) => 0))
+  (fact @reported => (user-error-with-notes #"inlined")))
+
 ;; How it works
 
 (defn ^{:dynamic true} function-symbol-of-interest [n] n)

test/midje/test_util.clj

@@ -68,3 +68,8 @@
 
 (defn at-line [line-no form] (with-meta form {:line line-no}))
 
+(defmacro user-error-with-notes [& notes]
+  `(just (contains {:notes (just ~@notes)
+                    :type :user-error})))
+
+