diff --git a/compiler/bin-wasmoo_util/tests/cram.t b/compiler/bin-wasmoo_util/tests/cram.t
new file mode 100644
index 0000000000..e41cd27179
--- /dev/null
+++ b/compiler/bin-wasmoo_util/tests/cram.t
@@ -0,0 +1,117 @@
+Too many parentheses
+
+  $ echo '())' | wasmoo_util pp
+  File "-", line 1, characters 2-3:
+  Unexpected closing parenthesis.
+  [1]
+
+Missing parenthesis
+
+  $ echo '(()' | wasmoo_util pp
+  File "-", line 2, characters 0-0:
+  Unexpected end of file.
+  [1]
+
+Bad conditional
+
+  $ echo '(@if)' | wasmoo_util pp
+  File "-", line 1, characters 4-5:
+  Expecting condition.
+  [1]
+
+  $ echo '(@if a)' | wasmoo_util pp
+  File "-", line 1, characters 6-7:
+  Expecting @then clause.
+  [1]
+
+  $ echo '(@if a xxx)' | wasmoo_util pp
+  File "-", line 1, characters 7-10:
+  Expecting @then clause.
+  [1]
+
+  $ echo '(@if a (@then) xx)' | wasmoo_util pp
+  File "-", line 1, characters 15-17:
+  Expecting @else clause or closing parenthesis.
+  [1]
+
+  $ echo '(@if a (@then) (@else) xx)' | wasmoo_util pp
+  File "-", line 1, characters 23-25:
+  Expecting closing parenthesis.
+  [1]
+
+Syntax error in condition
+
+  $ echo '(@if () (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-7:
+  Syntax error.
+  [1]
+
+  $ echo '(@if (not) (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-10:
+  Syntax error.
+  [1]
+
+  $ echo '(@if (not (and) (or)) (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-21:
+  Syntax error.
+  [1]
+
+  $ echo '(@if (= "a") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-12:
+  Syntax error.
+  [1]
+
+  $ echo '(@if (= "a" "b" "c") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-20:
+  Syntax error.
+  [1]
+
+Lonely @then or @else
+
+  $ echo '(@then)' | wasmoo_util pp
+  File "-", line 1, characters 5-20:
+  Syntax error.
+  [1]
+
+  $ echo '(@else)' | wasmoo_util pp
+  File "-", line 1, characters 5-20:
+  Syntax error.
+  [1]
+
+  $ echo '(@if (and) (@then (@else)))' | wasmoo_util pp
+  File "-", line 1, characters 5-20:
+  Syntax error.
+  [1]
+
+Undefined variable
+
+  $ echo '(@if a (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-6:
+  Unknown variable 'a'.
+  [1]
+
+Wrong type
+  $ echo '(@if "" (@then))' | wasmoo_util pp
+  File "-", line 1, characters 5-7:
+  Expected a boolean but this is a string.
+  [1]
+
+  $ echo '(@if (not "") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 10-12:
+  Expected a boolean but this is a string.
+  [1]
+
+  $ echo '(@if (and "") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 10-12:
+  Expected a boolean but this is a string.
+  [1]
+
+  $ echo '(@if (or "") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 9-11:
+  Expected a boolean but this is a string.
+  [1]
+
+  $ echo '(@if (= (and) "") (@then))' | wasmoo_util pp
+  File "-", line 1, characters 14-16:
+  Expected a boolean but this is a string.
+  [1]
diff --git a/compiler/bin-wasmoo_util/tests/dune b/compiler/bin-wasmoo_util/tests/dune
new file mode 100644
index 0000000000..8ea3e85995
--- /dev/null
+++ b/compiler/bin-wasmoo_util/tests/dune
@@ -0,0 +1,8 @@
+
+(rule
+ (with-stdout-to tests.output
+  (run wasmoo_util pp --enable a --disable b --set c=1 %{dep:tests.txt})))
+
+(rule
+ (alias runtest)
+ (action (diff tests.expected tests.output)))
diff --git a/compiler/bin-wasmoo_util/tests/tests.expected b/compiler/bin-wasmoo_util/tests/tests.expected
new file mode 100644
index 0000000000..8869679877
--- /dev/null
+++ b/compiler/bin-wasmoo_util/tests/tests.expected
@@ -0,0 +1,63 @@
+;; conditional
+              a is true                     
+                                b is false  
+              a is true  
+                         
+
+;; nested conditionals
+                                                     a is true and b is false  
+                                                                            
+
+;; not
+                                
+                    b is false  
+
+;; and
+                  true  
+                    a is true  
+                               
+                                        
+                            a is true and b is false  
+                                                      
+                                                     
+
+;; or
+                        
+                   a is true  
+                              
+                     a or b is true  
+                           a is true or b is false  
+                                                    
+                                 a or b is false  
+
+;; string comparisons
+                      c is 1  
+                              
+                                   
+                       c is not 2  
+
+;; version comparisons
+                                                   
+                                (4 1 1) = (4 1 1)  
+                                                   
+                                 (4 1 1) <> (4 1 0)  
+                                                     
+                                 (4 1 1) <> (4 1 2)  
+                                                     
+                                 (4 1 1) <= (4 1 1)  
+                                 (4 1 1) <= (4 1 2)  
+                                 (4 1 1) >= (4 1 0)  
+                                 (4 1 1) >= (4 1 1)  
+                                                     
+                                (4 1 1) > (4 1 0)  
+                                                   
+                                                   
+
+;; version comparisons: lexicographic order
+                                                   
+                                                   
+                                (4 1 1) < (4 1 2)  
+                                                   
+                                (4 1 1) < (4 2 0)  
+                                (4 1 1) < (5 0 1)  
+                                                   
diff --git a/compiler/bin-wasmoo_util/tests/tests.txt b/compiler/bin-wasmoo_util/tests/tests.txt
new file mode 100644
index 0000000000..f25e63f874
--- /dev/null
+++ b/compiler/bin-wasmoo_util/tests/tests.txt
@@ -0,0 +1,63 @@
+;; conditional
+(@if a (@then a is true) (@else a is false))
+(@if b (@then b is true) (@else b is false))
+(@if a (@then a is true))
+(@if b (@then b is true))
+
+;; nested conditionals
+(@if a (@then (@if b (@then a and b are true) (@else a is true and b is false)))
+ (@else (@if b (@then a is false and b is true) (@else a and b are false))))
+
+;; not
+(@if (not a) (@then a is false))
+(@if (not b) (@then b is false))
+
+;; and
+(@if (and) (@then true))
+(@if (and a) (@then a is true))
+(@if (and b) (@then b is true))
+(@if (and a b) (@then a and b are true))
+(@if (and a (not b)) (@then a is true and b is false))
+(@if (and (not a) b) (@then a is false and b is true))
+(@if (and (not a) (not b)) (@then a and b are false))
+
+;; or
+(@if (or) (@then false))
+(@if (or a) (@then a is true))
+(@if (or b) (@then b is true))
+(@if (or a b) (@then a or b is true))
+(@if (or a (not b)) (@then a is true or b is false))
+(@if (or (not a) b) (@then a is false or b is true))
+(@if (or (not a) (not b)) (@then a or b is false))
+
+;; string comparisons
+(@if (= c "1") (@then c is 1))
+(@if (= c "2") (@then c is 2))
+(@if (<> c "1") (@then c is not 1))
+(@if (<> c "2") (@then c is not 2))
+
+;; version comparisons
+(@if (= (4 1 1) (4 1 0)) (@then (4 1 1) = (4 1 0)))
+(@if (= (4 1 1) (4 1 1)) (@then (4 1 1) = (4 1 1)))
+(@if (= (4 1 1) (4 1 2)) (@then (4 1 1) = (4 1 2)))
+(@if (<> (4 1 1) (4 1 0)) (@then (4 1 1) <> (4 1 0)))
+(@if (<> (4 1 1) (4 1 1)) (@then (4 1 1) <> (4 1 1)))
+(@if (<> (4 1 1) (4 1 2)) (@then (4 1 1) <> (4 1 2)))
+(@if (<= (4 1 1) (4 1 0)) (@then (4 1 1) <= (4 1 0)))
+(@if (<= (4 1 1) (4 1 1)) (@then (4 1 1) <= (4 1 1)))
+(@if (<= (4 1 1) (4 1 2)) (@then (4 1 1) <= (4 1 2)))
+(@if (>= (4 1 1) (4 1 0)) (@then (4 1 1) >= (4 1 0)))
+(@if (>= (4 1 1) (4 1 1)) (@then (4 1 1) >= (4 1 1)))
+(@if (>= (4 1 1) (4 1 2)) (@then (4 1 1) >= (4 1 2)))
+(@if (> (4 1 1) (4 1 0)) (@then (4 1 1) > (4 1 0)))
+(@if (> (4 1 1) (4 1 1)) (@then (4 1 1) > (4 1 1)))
+(@if (> (4 1 1) (4 1 2)) (@then (4 1 1) > (4 1 2)))
+
+;; version comparisons: lexicographic order
+(@if (< (4 1 1) (4 1 0)) (@then (4 1 1) < (4 1 0)))
+(@if (< (4 1 1) (4 1 1)) (@then (4 1 1) < (4 1 1)))
+(@if (< (4 1 1) (4 1 2)) (@then (4 1 1) < (4 1 2)))
+(@if (< (4 1 1) (4 0 2)) (@then (4 1 1) < (4 0 2)))
+(@if (< (4 1 1) (4 2 0)) (@then (4 1 1) < (4 2 0)))
+(@if (< (4 1 1) (5 0 1)) (@then (4 1 1) < (5 0 1)))
+(@if (< (4 1 1) (3 2 1)) (@then (4 1 1) < (3 2 1)))