diff --git a/test/testingTypeFun.expected b/test/testingTypeFun.expected
index 4dcb90d..9cb2292 100644
--- a/test/testingTypeFun.expected
+++ b/test/testingTypeFun.expected
@@ -1,3 +1,12 @@
+Error absent assignment program: error
+Error wrong arity program 1: error
+Error wrong arity program 2: error
+Error wrong return type program: error
+Error wrong specification program: error
+Error wrong input type program: error
+Error not a function program: error
+Error if branches with different types program: error
+Error if guard is not a boolean program: error
 Identity program: true
 Constant program: true
 Partial application of function program: true
diff --git a/test/testingTypeFun.ml b/test/testingTypeFun.ml
index c15c426..f7da472 100644
--- a/test/testingTypeFun.ml
+++ b/test/testingTypeFun.ml
@@ -1,5 +1,153 @@
 open Lang.MiniFun
 
+(* -------------------------------------------------------------------------- *)
+(* Error absent assignment program *)
+
+let program =
+  Function
+    (["a"],
+     FunctionType ([IntegerType], IntegerType),
+     (Variable "x")
+    )
+;;
+
+try
+  Printf.printf "Error absent assignment program: %b\n" (typecheck program)
+with AbsentAssignment _ ->
+  Printf.printf "Error absent assignment program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error wrong arity program *)
+
+let program =
+  Function
+    (["a"],
+     FunctionType ([IntegerType; IntegerType], IntegerType),
+     (Variable "a")
+    )
+;;
+
+try
+  Printf.printf "Error wrong arity program 1: %b\n" (typecheck program)
+with WrongTypeSpecification _ ->
+  Printf.printf "Error wrong arity program 1: error\n"
+
+let program =
+  LetFun
+    ("f",
+     ["a"; "b"],
+     FunctionType ([IntegerType; IntegerType], IntegerType),
+     (Variable "a"),
+     Function (["x"], FunctionType ([IntegerType], IntegerType), Application (Variable "f", [Integer 1; Integer 2; Variable "x"]))
+    )
+;;
+
+try
+  Printf.printf "Error wrong arity program 2: %b\n" (typecheck program)
+with WrongArity _ ->
+  Printf.printf "Error wrong arity program 2: error\n"
+
+
+(* -------------------------------------------------------------------------- *)
+(* Error wrong return type program *)
+
+let program =
+  Function
+    (["a"],
+     FunctionType ([IntegerType], BooleanType),
+     (Variable "a")
+    )
+;;
+
+try
+  Printf.printf "Error wrong return type program: %b\n" (typecheck program)
+with WrongTypeSpecification _ ->
+  Printf.printf "Error wrong return type program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error wrong specification program *)
+
+let program =
+  Function
+    (["a"],
+     IntegerType,
+     (Variable "a")
+    )
+;;
+
+try
+  Printf.printf "Error wrong specification program: %b\n" (typecheck program)
+with WrongTypeSpecification _ ->
+  Printf.printf "Error wrong specification program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error wrong input type program *)
+
+let program =
+  Application (
+    Function
+      (["a"; "b"],
+       FunctionType ([IntegerType; IntegerType], IntegerType),
+       (Variable "a")
+      ),
+    [Boolean false]
+  )
+;;
+
+try
+  Printf.printf "Error wrong input type program: %b\n" (typecheck program)
+with WrongType _ ->
+  Printf.printf "Error wrong input type program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error not a function program *)
+
+let program =
+  Application (
+    Integer 0,
+    [Boolean false]
+  )
+;;
+
+try
+  Printf.printf "Error not a function program: %b\n" (typecheck program)
+with WrongType _ ->
+  Printf.printf "Error not a function program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error if branches with different types program *)
+
+let program =
+  Function (
+    ["x"],
+    FunctionType ([IntegerType], IntegerType),
+    IfThenElse (Cmp (Integer 1, Integer 2), Boolean true, Integer 1)
+  )
+;;
+
+try
+  Printf.printf "Error if branches with different types program: %b\n" (typecheck program)
+with WrongType _ ->
+  Printf.printf "Error if branches with different types program: error\n"
+
+(* -------------------------------------------------------------------------- *)
+(* Error if guard is not a boolean program *)
+
+let program =
+  Function (
+    ["x"],
+    FunctionType ([IntegerType], IntegerType),
+    IfThenElse (Integer 1, Integer 2, Integer 1)
+  )
+;;
+
+try
+  Printf.printf "Error if guard is not a boolean program: %b\n" (typecheck program)
+with WrongType _ ->
+  Printf.printf "Error if guard is not a boolean program: error\n"
+
+
+
 (* -------------------------------------------------------------------------- *)
 (* Identity program *)
 let program =