test: Add demo3/demo exercise with a nonempty prepare.ml

Author: erikmd

demo-repository/exercises/demo3/demo/descr.md

@@ -0,0 +1,22 @@
+# id: `demo3/demo`
+
+This example demonstrates the ability to put exercises in sub-directories.
+
+## Questions
+
+Define four functions matching the usual arithmetic operations:
+
+```
+plus : int -> int -> int
+times : int -> int -> int
+minus : int -> int -> int
+divide : int -> int -> int
+```
+
+## Bonus question
+
+The hidden prelude (so-called `prepare.ml`) contains a predicate
+
+`mystere_int : int -> bool`
+
+so could you find for which `n` we get `mystere_int n = true` ?

demo-repository/exercises/demo3/demo/meta.json

@@ -0,0 +1,2 @@
+{"learnocaml_version":"1","kind":"exercise","stars":0,
+ "title":"Demo exercise (in a sub-directory)"}

demo-repository/exercises/demo3/demo/prelude.ml

@@ -0,0 +1,2 @@
+(* Some code is loaded in the toplevel before your code. *)
+let greetings = "Hello world!"

demo-repository/exercises/demo3/demo/prepare.ml

@@ -0,0 +1 @@
+let mystere_int n = n = 12345

demo-repository/exercises/demo3/demo/solution.ml

@@ -0,0 +1,4 @@
+let plus = (+)
+let times = ( * )
+let minus = ( - )
+let divide = ( / )

demo-repository/exercises/demo3/demo/template.ml

@@ -0,0 +1,6 @@
+
+let plus x y = x + y ;;
+
+let minus x y = y - x ;;
+
+let times x y = x *

demo-repository/exercises/demo3/demo/test.ml

@@ -0,0 +1,26 @@
+open Test_lib
+open Report
+
+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) ]) ;
+    Section
+      ([ Text "Function:" ; Code "minus" ],
+       test_function_2_against_solution
+         [%ty : int -> int -> int ] "minus"
+         [ (1, 1) ; (4, -2) ; (0, 10) ]) ;
+    Section
+      ([ Text "Function:" ; Code "times" ],
+       test_function_2_against_solution
+         [%ty : int -> int -> int ] "times"
+         [ (1, 3) ; (2, 4) ; (3, 0) ]) ;
+    Section
+      ([ Text "Function:" ; Code "divide" ],
+       test_function_2_against_solution
+         [%ty : int -> int -> int ] "divide"
+         [ (12, 4) ; (12, 5) ; (3, 0) ]) ]

demo-repository/exercises/index.json

@@ -2,4 +2,4 @@
   "groups":
   { "demo":
     { "title": "Demo exercise pack",
-      "exercises": [ "demo", "demo2" ] } } }
+      "exercises": [ "demo", "demo2", "demo3/demo" ] } } }