From 16bb0c93e7c56afddd0228231f40af3c5dbd6cf8 Mon Sep 17 00:00:00 2001
From: "Paul Gauthier (aider)" <paul@aider.chat>
Date: Mon, 31 Mar 2025 08:40:17 +1300
Subject: [PATCH] feat: Warn when using --stream and --cache-prompts together

---
 aider/main.py            |  6 +++---
 tests/basic/test_main.py | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/aider/main.py b/aider/main.py
index 652425905..1df438843 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -579,9 +579,6 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
         io = get_io(False)
         io.tool_warning("Terminal does not support pretty output (UnicodeDecodeError)")
 
-    if args.stream and args.cache_prompts:
-        io.tool_warning("Cost estimates may be inaccurate when using streaming and caching.")
-
     # Process any environment variables set via --set-env
     if args.set_env:
         for env_setting in args.set_env:
@@ -1065,6 +1062,9 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
         io.tool_output(f"Cur working dir: {Path.cwd()}")
         io.tool_output(f"Git working dir: {git_root}")
 
+    if args.stream and args.cache_prompts:
+        io.tool_warning("Cost estimates may be inaccurate when using streaming and caching.")
+
     if args.load:
         commands.cmd_load(args.load)
 
diff --git a/tests/basic/test_main.py b/tests/basic/test_main.py
index a6dead0ff..a53ce67a5 100644
--- a/tests/basic/test_main.py
+++ b/tests/basic/test_main.py
@@ -1246,3 +1246,40 @@ class TestMain(TestCase):
                 # Only set_reasoning_effort should be called, not set_thinking_tokens
                 mock_instance.set_reasoning_effort.assert_called_once_with("3")
                 mock_instance.set_thinking_tokens.assert_not_called()
+
+    @patch("aider.main.InputOutput")
+    def test_stream_and_cache_warning(self, MockInputOutput):
+        mock_io_instance = MockInputOutput.return_value
+        with GitTemporaryDirectory():
+            main(
+                ["--stream", "--cache-prompts", "--exit", "--yes"],
+                input=DummyInput(),
+                output=DummyOutput(),
+            )
+        mock_io_instance.tool_warning.assert_called_with(
+            "Cost estimates may be inaccurate when using streaming and caching."
+        )
+
+    @patch("aider.main.InputOutput")
+    def test_stream_without_cache_no_warning(self, MockInputOutput):
+        mock_io_instance = MockInputOutput.return_value
+        with GitTemporaryDirectory():
+            main(
+                ["--stream", "--exit", "--yes"],
+                input=DummyInput(),
+                output=DummyOutput(),
+            )
+        for call in mock_io_instance.tool_warning.call_args_list:
+            self.assertNotIn("Cost estimates may be inaccurate", call[0][0])
+
+    @patch("aider.main.InputOutput")
+    def test_cache_without_stream_no_warning(self, MockInputOutput):
+        mock_io_instance = MockInputOutput.return_value
+        with GitTemporaryDirectory():
+            main(
+                ["--cache-prompts", "--exit", "--yes"],
+                input=DummyInput(),
+                output=DummyOutput(),
+            )
+        for call in mock_io_instance.tool_warning.call_args_list:
+            self.assertNotIn("Cost estimates may be inaccurate", call[0][0])