Mutation testing functionality

demo-repository/exercises/demo/descr.html

@@ -9,18 +9,52 @@ <h2>The task</h2>
   integer-arithmetic functions.
 </p>
 
+<p>
+  You are also asked to write test suites for these functions. A test
+  suite is specified as a list of input/expected output pairs. These
+  tests will be run against some buggy programs to test their coverage.
+</p>
+
 <ol>
   <li>
     Write a function <code>plus</code> of type <code>int -> int -> int</code>.
+    <ul>
+      <li>
+        Write some test cases for this function in the variable
+        <code>plus_tests</code>. Your test cases should be pairs of type
+        <code>(int * int) * int</code>.
+      </li>
+    </ul>
   </li>
   <li>
     Write a function <code>minus</code> of type <code>int -> int -> int</code>.
+    <ul>
+      <li>
+        Write some test cases for this function in the variable
+        <code>minus_tests</code>. Your test cases should be pairs of type
+        <code>(int * int) * int</code>.
+      </li>
+    </ul>
   </li>
   <li>
     Write a function <code>times</code> of type <code>int -> int -> int</code>.
+    <ul>
+      <li>
+        Write some test cases for this function in the variable
+        <code>times_tests</code>. Your test cases should be pairs of type
+        <code>(int * int) * int</code>.
+      </li>
+    </ul>
   </li>
   <li>
     Write a function <code>divide</code> of type <code>int -> int -> int</code>.
+    <ul>
+      <li>
+        Write some test cases for this function in the variable
+        <code>divide_tests</code>. Your test cases should be pairs of type
+        <code>(int * int) * int</code>.
+      </li>
+    </ul>
   </li>
 </ol>
 

demo-repository/exercises/demo/solution.ml

@@ -1,4 +1,11 @@
 let plus = (+)
+let plus_tests = [((1, 1), 2)]
+
 let times = ( * )
+let times_tests = [((2, 2), 4)]
+
 let minus = ( - )
+let minus_tests = [((1, 1), 0)]
+
 let divide = ( / )
+let divide_tests = [((2, 2), 1)]

demo-repository/exercises/demo/template.ml

@@ -1,6 +1,13 @@
 
 let plus x y = x + y ;;
+let plus_tests = [
+  ((1, 1), 2);
+  ((1, 0), 1)
+];;
 
 let minus x y = y - x ;;
+let minus_tests = [
+  ((1, 2), 1)
+];;
 
 let times x y = x *

demo-repository/exercises/demo/test.ml

@@ -1,26 +1,57 @@
 open Test_lib
 open Report
 
+module Mutation_test = Mutation_test.Make (Test_lib)
+open Mutation_test
+
+let test_plus () =
+  test_function_2_against_solution
+    [%ty : int -> int -> int ] "plus"
+    [ (1, 1) ; (2, 2) ; (10, -10) ]
+  @
+  test_unit_tests_2
+    [%ty : int -> int -> int ] "plus"
+    [ ("Subtracts instead of adding", 1, fun x y -> x - y) ]
+
+let test_minus () =
+  test_function_2_against_solution
+    [%ty : int -> int -> int ] "minus"
+    [ (1, 1) ; (4, -2) ; (0, 10) ]
+  @
+  test_unit_tests_2
+    [%ty : int -> int -> int ] "minus"
+    [ ("Adds instead of subtracting", 1, fun x y -> x + y) ]
+
+let test_times () =
+  test_function_2_against_solution
+    [%ty : int -> int -> int ] "times"
+    [ (1, 3) ; (2, 4) ; (3, 0) ]
+  @
+  test_unit_tests_2
+    [%ty: int -> int -> int ] "times"
+    [ ("Divides instead of multiplying", 1, fun x y -> x / y) ]
+
+let test_divide () =
+  test_function_2_against_solution
+    [%ty : int -> int -> int ] "divide"
+    [ (12, 4) ; (12, 5) ; (3, 0) ]
+  @
+  test_unit_tests_2
+    [%ty : int -> int -> int ] "divide"
+    [ ("Multiplies instead of dividing", 1, fun x y -> x * y) ]
+
 let () =
   set_result @@
   ast_sanity_check code_ast @@ fun () ->
   [ Section
       ([ Text "Function:" ; Code "plus" ],
-       test_function_2_against_solution
-         [%ty : int -> int -> int ] "plus"
-         [ (1, 1) ; (2, 2) ; (10, -10) ]) ;
+       test_plus ()) ;
     Section
       ([ Text "Function:" ; Code "minus" ],
-       test_function_2_against_solution
-         [%ty : int -> int -> int ] "minus"
-         [ (1, 1) ; (4, -2) ; (0, 10) ]) ;
+       test_minus ()) ;
     Section
       ([ Text "Function:" ; Code "times" ],
-       test_function_2_against_solution
-         [%ty : int -> int -> int ] "times"
-         [ (1, 3) ; (2, 4) ; (3, 0) ]) ;
+       test_times ()) ;
     Section
       ([ Text "Function:" ; Code "divide" ],
-       test_function_2_against_solution
-         [%ty : int -> int -> int ] "divide"
-         [ (12, 4) ; (12, 5) ; (3, 0) ]) ]
+       test_divide ()) ]

src/grader/dune

@@ -27,7 +27,8 @@
             learnocaml_repository)
  (modules Introspection_intf
           Introspection
-          Test_lib)
+          Test_lib
+          Mutation_test)
  (modules_without_implementation Introspection_intf)
  (preprocess (pps learnocaml_ppx_metaquot))
 )
@@ -106,7 +107,8 @@
         ../ppx-metaquot/.ty.objs/ty.cmi
         .testing.objs/introspection_intf.cmi
         .learnocaml_report.objs/learnocaml_report.cmi
-        .testing.objs/test_lib.cmi))
+        .testing.objs/test_lib.cmi
+        .testing.objs/mutation_test.cmi))
  (action (with-stdout-to %{targets}
            (run ocp-ocamlres -format ocamlres %{compiler-cmis} %{generated-cmis})))
 )