[ci] Add automated memory impact analysis for pull requests (#11242)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

script/determine-jobs.py

@@ -10,7 +10,13 @@ what files have changed. It outputs JSON with the following structure:
   "clang_format": true/false,
   "python_linters": true/false,
   "changed_components": ["component1", "component2", ...],
-  "component_test_count": 5
+  "component_test_count": 5,
+  "memory_impact": {
+    "should_run": "true/false",
+    "components": ["component1", "component2", ...],
+    "platform": "esp32-idf",
+    "use_merged_config": "true"
+  }
 }
 
 The CI workflow uses this information to:
@@ -20,6 +26,7 @@ The CI workflow uses this information to:
 - Skip or run Python linters (ruff, flake8, pylint, pyupgrade)
 - Determine which components to test individually
 - Decide how to split component tests (if there are many)
+- Run memory impact analysis whenever there are changed components (merged config), and also for core-only changes
 
 Usage:
   python script/determine-jobs.py [-b BRANCH]
@@ -31,6 +38,8 @@ Options:
 from __future__ import annotations
 
 import argparse
+from collections import Counter
+from enum import StrEnum
 from functools import cache
 import json
 import os
@@ -40,16 +49,47 @@ import sys
 from typing import Any
 
 from helpers import (
+    BASE_BUS_COMPONENTS,
     CPP_FILE_EXTENSIONS,
-    ESPHOME_COMPONENTS_PATH,
     PYTHON_FILE_EXTENSIONS,
     changed_files,
     get_all_dependencies,
+    get_component_from_path,
+    get_component_test_files,
     get_components_from_integration_fixtures,
+    parse_test_filename,
     root_path,
 )
 
 
+class Platform(StrEnum):
+    """Platform identifiers for memory impact analysis."""
+
+    ESP8266_ARD = "esp8266-ard"
+    ESP32_IDF = "esp32-idf"
+    ESP32_C3_IDF = "esp32-c3-idf"
+    ESP32_C6_IDF = "esp32-c6-idf"
+    ESP32_S2_IDF = "esp32-s2-idf"
+    ESP32_S3_IDF = "esp32-s3-idf"
+
+
+# Memory impact analysis constants
+MEMORY_IMPACT_FALLBACK_COMPONENT = "api"  # Representative component for core changes
+MEMORY_IMPACT_FALLBACK_PLATFORM = Platform.ESP32_IDF  # Most representative platform
+
+# Platform preference order for memory impact analysis
+# Prefer newer platforms first as they represent the future of ESPHome
+# ESP8266 is most constrained but many new features don't support it
+MEMORY_IMPACT_PLATFORM_PREFERENCE = [
+    Platform.ESP32_C6_IDF,  # ESP32-C6 IDF (newest, supports Thread/Zigbee)
+    Platform.ESP8266_ARD,  # ESP8266 Arduino (most memory constrained - best for impact analysis)
+    Platform.ESP32_IDF,  # ESP32 IDF platform (primary ESP32 platform, most representative)
+    Platform.ESP32_C3_IDF,  # ESP32-C3 IDF
+    Platform.ESP32_S2_IDF,  # ESP32-S2 IDF
+    Platform.ESP32_S3_IDF,  # ESP32-S3 IDF
+]
+
+
 def should_run_integration_tests(branch: str | None = None) -> bool:
     """Determine if integration tests should run based on changed files.
 
@@ -105,12 +145,9 @@ def should_run_integration_tests(branch: str | None = None) -> bool:
 
     # Check if any required components changed
     for file in files:
-        if file.startswith(ESPHOME_COMPONENTS_PATH):
-            parts = file.split("/")
-            if len(parts) >= 3:
-                component = parts[2]
-                if component in all_required_components:
-                    return True
+        component = get_component_from_path(file)
+        if component and component in all_required_components:
+            return True
 
     return False
 
@@ -224,10 +261,136 @@ def _component_has_tests(component: str) -> bool:
     Returns:
         True if the component has test YAML files
     """
-    tests_dir = Path(root_path) / "tests" / "components" / component
-    if not tests_dir.exists():
-        return False
-    return any(tests_dir.glob("test.*.yaml"))
+    return bool(get_component_test_files(component))
+
+
+def detect_memory_impact_config(
+    branch: str | None = None,
+) -> dict[str, Any]:
+    """Determine memory impact analysis configuration.
+
+    Always runs memory impact analysis when there are changed components,
+    building a merged configuration with all changed components (like
+    test_build_components.py does) to get comprehensive memory analysis.
+
+    Args:
+        branch: Branch to compare against
+
+    Returns:
+        Dictionary with memory impact analysis parameters:
+        - should_run: "true" or "false"
+        - components: list of component names to analyze
+        - platform: platform name for the merged build
+        - use_merged_config: "true" (always use merged config)
+    """
+
+    # Get actually changed files (not dependencies)
+    files = changed_files(branch)
+
+    # Find all changed components (excluding core and base bus components)
+    changed_component_set: set[str] = set()
+    has_core_changes = False
+
+    for file in files:
+        component = get_component_from_path(file)
+        if component:
+            # Skip base bus components as they're used across many builds
+            if component not in BASE_BUS_COMPONENTS:
+                changed_component_set.add(component)
+        elif file.startswith("esphome/"):
+            # Core ESPHome files changed (not component-specific)
+            has_core_changes = True
+
+    # If no components changed but core changed, test representative component
+    force_fallback_platform = False
+    if not changed_component_set and has_core_changes:
+        print(
+            f"Memory impact: No components changed, but core files changed. "
+            f"Testing {MEMORY_IMPACT_FALLBACK_COMPONENT} component on {MEMORY_IMPACT_FALLBACK_PLATFORM}.",
+            file=sys.stderr,
+        )
+        changed_component_set.add(MEMORY_IMPACT_FALLBACK_COMPONENT)
+        force_fallback_platform = True  # Use fallback platform (most representative)
+    elif not changed_component_set:
+        # No components and no core changes
+        return {"should_run": "false"}
+
+    # Find components that have tests and collect their supported platforms
+    components_with_tests: list[str] = []
+    component_platforms_map: dict[
+        str, set[Platform]
+    ] = {}  # Track which platforms each component supports
+
+    for component in sorted(changed_component_set):
+        # Look for test files on preferred platforms
+        test_files = get_component_test_files(component)
+        if not test_files:
+            continue
+
+        # Check if component has tests for any preferred platform
+        available_platforms = [
+            platform
+            for test_file in test_files
+            if (platform := parse_test_filename(test_file)[1]) != "all"
+            and platform in MEMORY_IMPACT_PLATFORM_PREFERENCE
+        ]
+
+        if not available_platforms:
+            continue
+
+        component_platforms_map[component] = set(available_platforms)
+        components_with_tests.append(component)
+
+    # If no components have tests, don't run memory impact
+    if not components_with_tests:
+        return {"should_run": "false"}
+
+    # Find common platforms supported by ALL components
+    # This ensures we can build all components together in a merged config
+    common_platforms = set(MEMORY_IMPACT_PLATFORM_PREFERENCE)
+    for component, platforms in component_platforms_map.items():
+        common_platforms &= platforms
+
+    # Select the most preferred platform from the common set
+    # Exception: for core changes, use fallback platform (most representative of codebase)
+    if force_fallback_platform:
+        platform = MEMORY_IMPACT_FALLBACK_PLATFORM
+    elif common_platforms:
+        # Pick the most preferred platform that all components support
+        platform = min(common_platforms, key=MEMORY_IMPACT_PLATFORM_PREFERENCE.index)
+    else:
+        # No common platform - pick the most commonly supported platform
+        # This allows testing components individually even if they can't be merged
+        # Count how many components support each platform
+        platform_counts = Counter(
+            p for platforms in component_platforms_map.values() for p in platforms
+        )
+        # Pick the platform supported by most components, preferring earlier in MEMORY_IMPACT_PLATFORM_PREFERENCE
+        platform = max(
+            platform_counts.keys(),
+            key=lambda p: (
+                platform_counts[p],
+                -MEMORY_IMPACT_PLATFORM_PREFERENCE.index(p),
+            ),
+        )
+
+    # Debug output
+    print("Memory impact analysis:", file=sys.stderr)
+    print(f"  Changed components: {sorted(changed_component_set)}", file=sys.stderr)
+    print(f"  Components with tests: {components_with_tests}", file=sys.stderr)
+    print(
+        f"  Component platforms: {dict(sorted(component_platforms_map.items()))}",
+        file=sys.stderr,
+    )
+    print(f"  Common platforms: {sorted(common_platforms)}", file=sys.stderr)
+    print(f"  Selected platform: {platform}", file=sys.stderr)
+
+    return {
+        "should_run": "true",
+        "components": components_with_tests,
+        "platform": platform,
+        "use_merged_config": "true",
+    }
 
 
 def main() -> None:
@@ -279,6 +442,9 @@ def main() -> None:
         if component not in directly_changed_components
     ]
 
+    # Detect components for memory impact analysis (merged config)
+    memory_impact = detect_memory_impact_config(args.branch)
+
     # Build output
     output: dict[str, Any] = {
         "integration_tests": run_integration,
@@ -292,6 +458,7 @@ def main() -> None:
         "component_test_count": len(changed_components_with_tests),
         "directly_changed_count": len(directly_changed_with_tests),
         "dependency_only_count": len(dependency_only_components),
+        "memory_impact": memory_impact,
     }
 
     # Output as JSON