add input compile error logic

unfold_studio/integration_tests/test_files/base_story_tester.py

@@ -218,3 +218,23 @@ def _wait_for_input_box_with_placeholder(self, placeholder):
                 pass
             time.sleep(0.5)
         raise TimeoutException(f"Input box with placeholder '{placeholder}' not found or not enabled within {timeout} seconds")
+
+    def assert_error_message(self, expected_error, timeout=10):
+        try:
+            WebDriverWait(self.driver, timeout).until(
+                lambda d: any(
+                    expected_error == error_element.text.strip()
+                    for error_element in d.find_elements(By.CLASS_NAME, "error")
+                )
+            )
+            print_green(f"✓ Found exact error message: '{expected_error}'")
+            return True
+        except TimeoutException:
+            error_elements = self.driver.find_elements(By.CLASS_NAME, "error")
+            error_texts = [elem.text.strip() for elem in error_elements]
+            print(f"✗ Error message not found. Expected: '{expected_error}'")
+            print(f"Found error elements: {error_texts}")
+            raise TimeoutException(
+                f"Timeout waiting for exact error message: '{expected_error}'\n"
+                f"Found error elements: {error_texts}"
+            )

unfold_studio/integration_tests/test_files/run_all_tests.py

@@ -19,7 +19,7 @@ def main():
         'test_input_generate.py',
         'test_input_generate2.py',
         'test_input_generate3.py',
-        'test_continue.py'
+        'test_continue.py',
     ]
 
     success_count = 0

unfold_studio/unfold_studio/models.py

@@ -235,6 +235,15 @@ def include(base, new):
             include(variables, iVars)
             include(knots, iKnots)
 
+        # Check for undefined input variables
+        input_vars = self.get_input_variables()
+        undefined_vars = [var for var in input_vars if var not in variables]
+        if undefined_vars:
+            raise Story.PreprocessingError(
+                StoryError.ErrorTypes.PREPROCESS_ERROR,
+                message=f"Input variables must be defined before use. Undefined variables: {', '.join(undefined_vars)}"
+            )
+
         inkText = "\n".join(
             self.external_function_declarations() +  # call-outs to javascript
             [l for i, l in variables.values()] +    # lifted variable initializations
@@ -372,6 +381,16 @@ def get_variable_initializations(self):
                 variableInits[result.group(2)] = (lineNum+1, line)
         return variableInits
 
+    def get_input_variables(self):
+        "Returns a set of variable names used in input calls"
+        input_vars = set()
+        input_pattern = r'~\s*input\s*\([^,]+,\s*"([^"]+)"\)'
+        for line in self.ink.split("\n"):
+            match = re.search(input_pattern, line)
+            if match:
+                input_vars.add(match.group(1))
+        return input_vars
+
     def get_ink_preamble(self, stripped=True):
         "Returns the content before the first knot"
         try: