devplacepy/services/ai_modifier.py

@@ -31,7 +31,13 @@ def modify_text(
         "The user's message contains an inline instruction marked with @ai. "
         + (prompt or DEFAULT_MODIFIER_PROMPT).strip()
         + " Return ONLY the resulting text, with no preamble, no explanation, no "
-        "quotes and no code fences."
+        "quotes and no code fences.\n"
+        "Rules:\n"
+        "1. Do NOT modify content inside Markdown fenced code blocks (delimited by "
+        "triple backticks). Preserve the code block fences, the language identifier, "
+        "and the code content exactly as written.\n"
+        "2. Only modify prose outside code blocks. Apply the modification prompt only "
+        "to non-code text."
     )
     if context:
         system += (

devplacepy/services/correction.py

@@ -124,8 +124,15 @@ def correct_text(api_key: str, prompt: str, text: str) -> tuple[str, dict | None
     system = (
         "You are a text correction engine. Apply the correction instruction below to "
         "the user's message and return ONLY the resulting text, with no preamble, no "
-        "explanation, no quotes and no code fences. Preserve the original meaning, "
-        "language, line breaks and markdown. Correction instruction: "
+        "explanation, no quotes and no code fences.\n"
+        "Rules:\n"
+        "1. Do NOT modify content inside Markdown fenced code blocks (delimited by "
+        "triple backticks). Preserve the code block fences, the language identifier, "
+        "and the code content exactly as written.\n"
+        "2. Only correct prose outside code blocks. Apply the correction prompt only "
+        "to non-code text.\n"
+        "3. Preserve the original meaning, language, line breaks, and markdown.\n"
+        "Correction instruction: "
         + (prompt or DEFAULT_CORRECTION_PROMPT).strip()
     )
     return gateway_complete(

tests/unit/services/ai_modifier.py

@@ -0,0 +1,38 @@
+# retoor <retoor@molodetz.nl>
+
+import unittest.mock
+
+from devplacepy.services.ai_modifier import modify_text
+
+
+def test_modify_text_prompt_preserves_fenced_code_blocks():
+    captured = {}
+
+    def fake_gateway(api_key, system, text, timeout, max_growth_factor):
+        captured["system"] = system
+        captured["text"] = text
+        return ("fake result", {"calls": 1})
+
+    with unittest.mock.patch(
+        "devplacepy.services.correction.gateway_complete", fake_gateway
+    ):
+        result, _ = modify_text(
+            "test-key",
+            "Make it more formal",
+            "Some text\n```python\nx = 1\n```\nMore text",
+        )
+
+    assert result == "fake result"
+    system = captured["system"]
+    assert (
+        "Do NOT modify content inside Markdown fenced code blocks" in system
+    ), "System prompt must instruct the model to preserve code blocks"
+    assert (
+        "Preserve the code block fences, the language identifier" in system
+    ), "System prompt must mention preserving language identifiers"
+    assert (
+        "Only modify prose outside code blocks" in system
+    ), "System prompt must limit modifications to non-code text"
+    assert (
+        "triple backticks" in system
+    ), "System prompt must mention triple backticks as the delimiter"

tests/unit/services/correction.py

@@ -0,0 +1,36 @@
+# retoor <retoor@molodetz.nl>
+
+import unittest.mock
+
+from devplacepy.services.correction import correct_text
+
+
+def test_correct_text_prompt_preserves_fenced_code_blocks():
+    captured = {}
+
+    def fake_gateway(api_key, system, text, timeout, max_growth_factor):
+        captured["system"] = system
+        captured["text"] = text
+        return ("fake result", {"calls": 1})
+
+    with unittest.mock.patch(
+        "devplacepy.services.correction.gateway_complete", fake_gateway
+    ):
+        result, _ = correct_text(
+            "test-key", "Fix spelling", "Some text\n```python\nx = 1\n```\nMore text"
+        )
+
+    assert result == "fake result"
+    system = captured["system"]
+    assert (
+        "Do NOT modify content inside Markdown fenced code blocks" in system
+    ), "System prompt must instruct the model to preserve code blocks"
+    assert (
+        "Preserve the code block fences, the language identifier" in system
+    ), "System prompt must mention preserving language identifiers"
+    assert (
+        "Only correct prose outside code blocks" in system
+    ), "System prompt must limit corrections to non-code text"
+    assert (
+        "triple backticks" in system
+    ), "System prompt must mention triple backticks as the delimiter"