From a14c44f30ea7741aaededf6c6d182303bc08405b Mon Sep 17 00:00:00 2001
From: Konv Suu <2583695112@qq.com>
Date: Thu, 27 Nov 2025 14:23:14 +0800
Subject: [PATCH] Fix `K3WX.yaml` (comments in map key) bug in
 `yaml-test-suite` (#18324)

Co-authored-by: fisker Cheung <lionkay@gmail.com>
---
 changelog_unreleased/yaml/18324.md            | 15 ++++++
 src/language-yaml/print/mapping-item.js       |  1 +
 .../__snapshots__/format.test.js.snap         | 53 +++++++++++++++++++
 .../yaml/flow-mapping/comments/format.test.js |  1 +
 .../format/yaml/flow-mapping/comments/key.yml | 20 +++++++
 .../__snapshots__/format.test.js.snap         | 18 +++++++
 .../yaml/yaml-test-suite/format.test.js       |  1 -
 7 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 changelog_unreleased/yaml/18324.md
 create mode 100644 tests/format/yaml/flow-mapping/comments/__snapshots__/format.test.js.snap
 create mode 100644 tests/format/yaml/flow-mapping/comments/format.test.js
 create mode 100644 tests/format/yaml/flow-mapping/comments/key.yml

diff --git a/changelog_unreleased/yaml/18324.md b/changelog_unreleased/yaml/18324.md
new file mode 100644
index 000000000..1736d6afc
--- /dev/null
+++ b/changelog_unreleased/yaml/18324.md
@@ -0,0 +1,15 @@
+#### Use explicit key style for flow-mapping keys with trailing comments (#18324 by @kovsu, @fisker)
+
+<!-- prettier-ignore -->
+```yaml
+# Input
+{ "foo" # comment
+  :bar }
+
+# Prettier stable
+{ "foo": bar } # comment
+
+# Prettier main
+{ ? "foo" # comment
+  : bar }
+```
diff --git a/src/language-yaml/print/mapping-item.js b/src/language-yaml/print/mapping-item.js
index 233816c50..3eb1645c2 100644
--- a/src/language-yaml/print/mapping-item.js
+++ b/src/language-yaml/print/mapping-item.js
@@ -135,6 +135,7 @@ function printMappingItem(path, options, print) {
     isAbsolutelyPrintedAsSingleLineNode(key.content, options) &&
     !hasLeadingComments(key.content) &&
     !hasMiddleComments(key.content) &&
+    !hasTrailingComment(key.content) &&
     !hasEndComments(key)
   ) {
     return conditionalGroup([[printedKey, implicitMappingValue]]);
diff --git a/tests/format/yaml/flow-mapping/comments/__snapshots__/format.test.js.snap b/tests/format/yaml/flow-mapping/comments/__snapshots__/format.test.js.snap
new file mode 100644
index 000000000..4d86e19d7
--- /dev/null
+++ b/tests/format/yaml/flow-mapping/comments/__snapshots__/format.test.js.snap
@@ -0,0 +1,53 @@
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+
+exports[`key.yml format 1`] = `
+====================================options=====================================
+parsers: ["yaml"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+{"key" # 1
+:value}
+---
+{["key"] # 2
+:value}
+---
+{
+# 3
+"key"
+:value}
+---
+{
+&[
+"key",
+# 4
+""]
+:value}
+---
+{"key": # 1
+value}
+
+=====================================output=====================================
+{ ? "key" # 1
+  : value }
+---
+{ ? ["key"] # 2
+  : value }
+---
+{
+  # 3
+  "key": value,
+}
+---
+{ ? & [
+      "key",
+      # 4
+      "",
+    ]
+  : value }
+---
+{ ? "key" # 1
+  : value }
+
+================================================================================
+`;
diff --git a/tests/format/yaml/flow-mapping/comments/format.test.js b/tests/format/yaml/flow-mapping/comments/format.test.js
new file mode 100644
index 000000000..49e3f4bbf
--- /dev/null
+++ b/tests/format/yaml/flow-mapping/comments/format.test.js
@@ -0,0 +1 @@
+runFormatTest(import.meta, ["yaml"]);
diff --git a/tests/format/yaml/flow-mapping/comments/key.yml b/tests/format/yaml/flow-mapping/comments/key.yml
new file mode 100644
index 000000000..21530621c
--- /dev/null
+++ b/tests/format/yaml/flow-mapping/comments/key.yml
@@ -0,0 +1,20 @@
+{"key" # 1
+:value}
+---
+{["key"] # 2
+:value}
+---
+{
+# 3
+"key"
+:value}
+---
+{
+&[
+"key",
+# 4
+""]
+:value}
+---
+{"key": # 1
+value}
diff --git a/tests/format/yaml/yaml-test-suite/__snapshots__/format.test.js.snap b/tests/format/yaml/yaml-test-suite/__snapshots__/format.test.js.snap
index 6a9618e22..d1bd229ee 100644
--- a/tests/format/yaml/yaml-test-suite/__snapshots__/format.test.js.snap
+++ b/tests/format/yaml/yaml-test-suite/__snapshots__/format.test.js.snap
@@ -3847,6 +3847,24 @@ printWidth: 80
 ================================================================================
 `;
 
+exports[`snippet: K3WX.yaml - Colon and adjacent value after comment on next line format 1`] = `
+====================================options=====================================
+parsers: ["yaml"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+---
+{ "foo" # comment
+  :bar }
+
+=====================================output=====================================
+---
+{ ? "foo" # comment
+  : bar }
+
+================================================================================
+`;
+
 exports[`snippet: K4SU.yaml - Multiple Entry Block Sequence format 1`] = `
 ====================================options=====================================
 parsers: ["yaml"]
diff --git a/tests/format/yaml/yaml-test-suite/format.test.js b/tests/format/yaml/yaml-test-suite/format.test.js
index 872151321..c51396b85 100644
--- a/tests/format/yaml/yaml-test-suite/format.test.js
+++ b/tests/format/yaml/yaml-test-suite/format.test.js
@@ -20,7 +20,6 @@ const BUGS = new Set([
   "DE56-4.yaml",
   "JEF9-2.yaml",
   "JEF9-3.yaml",
-  "K3WX.yaml",
   "L24T-2.yaml",
 ]);