From ce5be77ed6a34f5777983181587fce0269c236bb Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 3 Jun 2026 01:09:01 -0500
Subject: [PATCH] [vscode] Mark the component key for "Component not found"
 errors
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The `vscode --ace` validator resolves an error's range to the deepest
matching node, which for a "Component not found" error is the component's
value mapping — so the range starts at the first child, and editors
underline the children instead of the offending top-level key. Request
the key's range for these errors (as already done for "extra keys not
allowed"). Backward compatible: only the range for this error type
changes.
---
 esphome/vscode.py               | 10 +++++++---
 tests/unit_tests/test_vscode.py | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/esphome/vscode.py b/esphome/vscode.py
index f404f02f00..f17565b7b1 100644
--- a/esphome/vscode.py
+++ b/esphome/vscode.py
@@ -13,9 +13,13 @@ from esphome.yaml_util import parse_yaml
 
 
 def _get_invalid_range(res: Config, invalid: cv.Invalid) -> DocumentRange | None:
-    return res.get_deepest_document_range_for_path(
-        invalid.path, invalid.error_message == "extra keys not allowed"
-    )
+    # Errors about the key itself (an unknown option, an unknown component)
+    # mark the key, not its value mapping — otherwise the range lands on the
+    # component's children instead of the offending key.
+    mark_key = invalid.error_message == "extra keys not allowed" or (
+        invalid.error_message or ""
+    ).startswith("Component not found:")
+    return res.get_deepest_document_range_for_path(invalid.path, mark_key)
 
 
 def _dump_range(range: DocumentRange | None) -> dict | None:
diff --git a/tests/unit_tests/test_vscode.py b/tests/unit_tests/test_vscode.py
index 63bdf3e255..20f6742cac 100644
--- a/tests/unit_tests/test_vscode.py
+++ b/tests/unit_tests/test_vscode.py
@@ -97,6 +97,39 @@ esp8266:
     assert range["end_col"] == 7
 
 
+def test_component_not_found_marks_key():
+    source_path = str(Path("dir_path", "x.yaml"))
+    output_lines = _run_repl_test(
+        [
+            _validate(source_path),
+            # read_file x.yaml
+            _file_response("""esphome:
+  name: test1
+esp8266:
+  board: esp01_1m
+
+apccci:
+  id: foo
+"""),
+        ]
+    )
+
+    error = json.loads(output_lines[-1])
+    not_found = next(
+        e
+        for e in error["validation_errors"]
+        if e["message"].startswith("Component not found:")
+    )
+    assert not_found["message"] == "Component not found: apccci."
+    # Range covers the ``apccci`` key, not its child mapping.
+    range = not_found["range"]
+    assert range["document"] == source_path
+    assert range["start_line"] == 5
+    assert range["start_col"] == 0
+    assert range["end_line"] == 5
+    assert range["end_col"] == 6
+
+
 def test_shows_correct_loaded_file_error():
     source_path = str(Path("dir_path", "x.yaml"))
     output_lines = _run_repl_test(