From c2b2aaddd1e0f024de5c156db9c5c88793c00472 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Fri, 20 Mar 2026 12:57:53 -1000
Subject: [PATCH] [sht4x] Move timestamp update after successful command, add
 heater test

Only advance last_heater_millis_ after the heater command succeeds
so a failed write retries on the next cycle instead of silently
skipping.

Add heater settings to the test YAML to ensure CI exercises the
heater code path.
---
 esphome/components/sht4x/sht4x.cpp | 11 ++++++-----
 tests/components/sht4x/common.yaml |  4 ++++
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/esphome/components/sht4x/sht4x.cpp b/esphome/components/sht4x/sht4x.cpp
index ff2f3da46a8..e8e84f535d0 100644
--- a/esphome/components/sht4x/sht4x.cpp
+++ b/esphome/components/sht4x/sht4x.cpp
@@ -86,11 +86,6 @@ void SHT4XComponent::update() {
     uint32_t now = millis();
     if (now - this->last_heater_millis_ >= this->heater_interval_) {
       use_heater = true;
-      // Ensure at least one normal measurement between heater cycles by
-      // pushing the next eligible heater time forward by one update interval.
-      // The configured duty cycle is a maximum, not an exact target.
-      uint32_t interval = std::max(this->heater_interval_, this->get_update_interval());
-      this->last_heater_millis_ = now - this->heater_interval_ + interval;
     }
   }
 
@@ -104,6 +99,12 @@ void SHT4XComponent::update() {
       this->status_set_warning(LOG_STR("Failed to send heater command"));
       return;
     }
+    // Only update timestamp after successful command. Ensure at least one
+    // normal measurement between heater cycles by pushing the next eligible
+    // heater time forward by at least one update interval.
+    uint32_t now = millis();
+    uint32_t interval = std::max(this->heater_interval_, this->get_update_interval());
+    this->last_heater_millis_ = now - this->heater_interval_ + interval;
     return;
   }
 
diff --git a/tests/components/sht4x/common.yaml b/tests/components/sht4x/common.yaml
index 50d5ad8ca46..bec192d6db5 100644
--- a/tests/components/sht4x/common.yaml
+++ b/tests/components/sht4x/common.yaml
@@ -6,4 +6,8 @@ sensor:
     humidity:
       name: SHT4X Humidity
     address: 0x44
+    precision: High
+    heater_max_duty: 0.02
+    heater_power: High
+    heater_time: Long
     update_interval: 15s