diff --git a/ast_generator/ast_generator.py b/ast_generator/ast_generator.py
index 21eae7f..3490121 100644
--- a/ast_generator/ast_generator.py
+++ b/ast_generator/ast_generator.py
@@ -186,7 +186,10 @@ class AstGenerator:
             i = 0
             for i in range(len(cutoffs) - 1):
                 if cutoffs[i] < a < cutoffs[i + 1]:
-                    options[i]()
+                    try:
+                        options[i]()
+                    except ValueError:
+                        break
                     break
 
     def generate_int_real_expr(self):
@@ -229,7 +232,7 @@ class AstGenerator:
             7: "or",
             8: "xor",
             9: "not",
-        }  # FIXME sometimes this will return a "" op, need to figure out why
+        }
 
         unary = ["not"]
 
@@ -268,7 +271,7 @@ class AstGenerator:
         self.current_nesting_depth -= 1
         self.current_ast_element = parent
 
-    def generate_declaration(self):
+    def generate_declaration(self, mut=None):
         parent = self.current_ast_element
         decl_type = self.get_type(GAZ_VAR_TAG)
         decl_args = [
@@ -278,7 +281,7 @@ class AstGenerator:
         self.current_ast_element.append(element)
         self.current_ast_element = element
 
-        variable = self.generate_variable(decl_type)
+        variable = self.generate_variable(decl_type, mut=mut)
         self.current_ast_element.append(variable.xml)
         self.current_scope.append(variable.name, variable)
 
@@ -374,6 +377,10 @@ class AstGenerator:
 
 
     def generate_assignment(self):
+        possible_vars = self.current_scope.get_all_defined_mutable_vars()
+        if len(possible_vars) == 0:
+            raise ValueError("No possible variables to assign to!")
+
         # same structure as a declaration
         parent = self.current_ast_element
 
@@ -381,12 +388,7 @@ class AstGenerator:
         self.current_ast_element.append(element)
         self.current_ast_element = element
 
-        possible_vars = self.current_scope.get_all_defined_mutable_vars()
-        if len(possible_vars) == 0:
-            self.generate_global()
-            possible_vars = self.current_scope.get_all_defined_mutable_vars()
 
-        assert len(possible_vars) > 0
         variable = random.choice(possible_vars)
 
         self.current_ast_element.append(variable.xml)
@@ -413,8 +415,12 @@ class AstGenerator:
 
         self.current_ast_element = parent
 
-    def generate_variable(self, var_type: str):
-        return Variable(self.get_name(GAZ_VAR_TAG), var_type, self.get_qualifier())
+    def generate_variable(self, var_type: str, mut=None):
+        if mut is None:
+            return Variable(self.get_name(GAZ_VAR_TAG), var_type, self.get_qualifier())
+        else:
+            return Variable(self.get_name(GAZ_VAR_TAG), var_type, mut)
+
 
     def generate_literal(self, var_type: str):
         args = [
diff --git a/ast_generator/test/test_ast_generator.py b/ast_generator/test/test_ast_generator.py
index ca85630..ed20b2d 100644
--- a/ast_generator/test/test_ast_generator.py
+++ b/ast_generator/test/test_ast_generator.py
@@ -232,10 +232,49 @@ class TestGeneration(unittest.TestCase):
             # self.write_ast()
 
             if self.ast_gen.ast.find("operator") is None:
+                l -= 1
                 continue
             operator = self.ast_gen.ast.find("operator")
             self.assertFalse(self.is_no_op(operator))
 
+    def test_create_global(self):
+        self.ast_gen.ast = ET.Element("block")
+        self.ast_gen.current_ast_element = self.ast_gen.ast
+        self.ast_gen.generate_main()
+
+        global_block = self.ast_gen.current_ast_element
+        global_scope = self.ast_gen.current_scope
+
+        self.assertIsNotNone(self.ast_gen.ast.find("procedure"))
+        self.ast_gen.current_ast_element = self.ast_gen.ast.find("procedure")
+        self.ast_gen.generate_global()
+
+        self.assertGreater(len(global_scope.symbols), 0)
+        self.assertIsNotNone(global_block.find("declaration"))
+
+    def test_generate_assignment_no_declaration(self):
+        for l in range(1000):
+            self.ast_gen.ast = ET.Element("block")
+            self.ast_gen.current_ast_element = self.ast_gen.ast
+            self.ast_gen.generate_declaration(mut='var')
+            self.ast_gen.generate_assignment()
+
+            self.assertIsNotNone(self.ast_gen.ast.find("assignment"))
+
+            decl = self.ast_gen.ast.find("assignment")
+            self.assertIsNone(decl.find("declaration"))
+
+    def test_failing_assignment(self):
+        self.ast_gen.ast = ET.Element("block")
+        self.ast_gen.current_ast_element = self.ast_gen.ast
+        self.ast_gen.generate_main()
+        with self.assertRaises(ValueError):
+            self.ast_gen.generate_assignment()
+
+        self.assertIsNone(self.ast_gen.ast.find("assignment"))
+
+
+
 
     def is_no_op(self, operator):
         """
diff --git a/ast_parser/general_unparser.py b/ast_parser/general_unparser.py
index 0fb59e7..64ea586 100644
--- a/ast_parser/general_unparser.py
+++ b/ast_parser/general_unparser.py
@@ -126,6 +126,8 @@ class GeneralUnparser:
         self.source += self.endline
 
     def unparse_variable(self, node, is_declaration: bool = False):
+        if node is None:
+            raise ValueError("Node is None")
         mut = node.get(GAZ_QUALIFIER_KEY)
         type = node.get(GAZ_TY_KEY)
         name = node.get(GAZ_NAME_KEY)
diff --git a/gazprea_fuzzer.py b/gazprea_fuzzer.py
index 4160e58..981e886 100644
--- a/gazprea_fuzzer.py
+++ b/gazprea_fuzzer.py
@@ -32,7 +32,7 @@ class Fuzzer():
             self.fuzzer.fuzz()
             dom = xml.dom.minidom.parseString(ET.tostring(self.fuzzer.ast).decode('utf-8'))
             pretty: str = dom.toprettyxml()
-            with open("fuzzer/source/{}_{}.in".format(self.file_name, i), 'w') as f:
+            with open("fuzzer/input/{}_{}.in".format(self.file_name, i), 'w') as f:
                 f.write(self.fuzzer.source)
             with open("fuzzer/debug/{}_{}.out".format(self.file_name, i), 'w') as f:
                 f.write(pretty)