From 6ca1b907520309e282a9b4eea4046b4c31c1b247 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 28 Jan 2026 18:14:03 -1000
Subject: [PATCH] Address Copilot review feedback

- Fix regex to actually match std::to_string() by using alternation
  (the : in the lookbehind was preventing matches)
- Update error message to mention both std::to_string() and
  unqualified to_string() forms
- Correct buffer sizes for signed integer types:
  - int8_t: 5 chars (not 4) for "-128\0"
  - int16_t: 7 chars (not 6) for "-32768\0"
  - int32_t: 12 chars (not 11) for "-2147483648\0"
---
 script/ci-custom.py | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/script/ci-custom.py b/script/ci-custom.py
index d436c25b600..864279cab8d 100755
--- a/script/ci-custom.py
+++ b/script/ci-custom.py
@@ -759,12 +759,13 @@ def lint_no_sprintf(fname, match):
 @lint_re_check(
     # Match std::to_string() or unqualified to_string() calls
     # The esphome namespace has "using std::to_string;" so unqualified calls resolve to std::to_string
-    # Use negative lookbehind to avoid matching:
+    # Use negative lookbehind for unqualified calls to avoid matching:
     #   - Function definitions: "const char *to_string(" or "std::string to_string("
     #   - Method definitions: "Class::to_string("
     #   - Method calls: ".to_string(" or "->to_string("
     #   - Other identifiers: "_to_string("
-    r"(?<![*&.\w>:])to_string\s*\(" + CPP_RE_EOL,
+    # Also explicitly match std::to_string since : is in the lookbehind
+    r"(?:(?<![*&.\w>:])to_string|std\s*::\s*to_string)\s*\(" + CPP_RE_EOL,
     include=cpp_include,
     exclude=[
         # Vendored library
@@ -779,15 +780,20 @@ def lint_no_sprintf(fname, match):
 )
 def lint_no_std_to_string(fname, match):
     return (
-        f"{highlight('std::to_string()')} allocates heap memory. On long-running embedded "
-        f"devices, repeated heap allocations fragment memory over time.\n"
+        f"{highlight('std::to_string()')} (including unqualified {highlight('to_string()')}) "
+        f"allocates heap memory. On long-running embedded devices, repeated heap allocations "
+        f"fragment memory over time.\n"
         f"Please use {highlight('snprintf()')} with a stack buffer instead.\n"
         f"\n"
-        f"Buffer sizes and format specifiers:\n"
-        f"  uint8_t/int8_t:   4 chars   - %u / %d (or PRIu8/PRId8)\n"
-        f"  uint16_t/int16_t: 6 chars   - %u / %d (or PRIu16/PRId16)\n"
-        f"  uint32_t/int32_t: 11 chars  - %" + "PRIu32 / %" + "PRId32\n"
-        "  uint64_t/int64_t: 21 chars  - %" + "PRIu64 / %" + "PRId64\n"
+        f"Buffer sizes and format specifiers (sizes include sign and null terminator):\n"
+        f"  uint8_t:          4 chars   - %u (or PRIu8)\n"
+        f"  int8_t:           5 chars   - %d (or PRId8)\n"
+        f"  uint16_t:         6 chars   - %u (or PRIu16)\n"
+        f"  int16_t:          7 chars   - %d (or PRId16)\n"
+        f"  uint32_t:         11 chars  - %" + "PRIu32\n"
+        "  int32_t:          12 chars  - %" + "PRId32\n"
+        "  uint64_t:         21 chars  - %" + "PRIu64\n"
+        "  int64_t:          21 chars  - %" + "PRId64\n"
         f"  float/double:     24 chars  - %.8g (15 digits + sign + decimal + e+XXX)\n"
         f"                    317 chars - %f (for DBL_MAX: 309 int digits + decimal + 6 frac + sign)\n"
         f"\n"