fix: fix regression of jsonc file with trailing comma or empty

Author: ntnyq

package.json

@@ -65,15 +65,15 @@
   },
   "dependencies": {
     "generate-differences": "^0.1.1",
-    "load-oxfmt-config": "^0.7.1",
+    "load-oxfmt-config": "^0.7.2",
     "picomatch": "^4.0.4",
     "synckit": "^0.11.12"
   },
   "devDependencies": {
     "@ntnyq/eslint-config": "^6.1.3",
     "@types/json-schema": "^7.0.15",
     "@types/node": "^25.6.2",
-    "@typescript/native-preview": "^7.0.0-dev.20260507.1",
+    "@typescript/native-preview": "^7.0.0-dev.20260508.1",
     "bumpp": "^11.1.0",
     "eslint": "^10.3.0",
     "eslint-parser-plain": "^0.1.1",

pnpm-lock.yaml

@@ -420,6 +420,104 @@ format(
 }
 `;
 
+exports[`should load .oxfmtrc.jsonc with trailing comma 1`] = `
+{
+  "fixture": "jsonc-trailing-comma",
+  "summary": [
+    {
+      "file": "src/example.js",
+      "messages": [
+        {
+          "column": 3,
+          "endColumn": 32,
+          "endLine": 2,
+          "fix": {
+            "text": "console.log(
+    'hello world',
+  )",
+          },
+          "line": 2,
+          "message": "Replace \`··console.log("hello·world");\` with \`console.log(⏎····'hello·world',⏎··)\`",
+          "messageId": "replace",
+          "ruleId": "oxfmt/oxfmt",
+          "severity": 2,
+        },
+        {
+          "column": 8,
+          "endColumn": 43,
+          "endLine": 5,
+          "fix": {
+            "text": "
+  reallyLongArg(),
+  anotherLongArg(),",
+          },
+          "line": 5,
+          "message": "Replace \`reallyLongArg(),·anotherLongArg());\` with \`⏎··reallyLongArg(),⏎··anotherLongArg(),\`",
+          "messageId": "replace",
+          "ruleId": "oxfmt/oxfmt",
+          "severity": 2,
+        },
+        {
+          "column": 1,
+          "endColumn": 1,
+          "endLine": 6,
+          "fix": {
+            "text": ")",
+          },
+          "line": 6,
+          "message": "Insert \`)\`",
+          "messageId": "insert",
+          "ruleId": "oxfmt/oxfmt",
+          "severity": 2,
+        },
+      ],
+      "output": "export function greet() {
+  console.log(
+    'hello world',
+  )
+}
+
+format(
+  reallyLongArg(),
+  anotherLongArg(),
+)",
+    },
+  ],
+}
+`;
+
+exports[`should load empty .oxfmtrc.jsonc 1`] = `
+{
+  "fixture": "jsonc-empty",
+  "summary": [
+    {
+      "file": "src/example.js",
+      "messages": [
+        {
+          "column": 3,
+          "endColumn": 5,
+          "endLine": 2,
+          "fix": {
+            "text": "",
+          },
+          "line": 2,
+          "message": "Delete \`··\`",
+          "messageId": "delete",
+          "ruleId": "oxfmt/oxfmt",
+          "severity": 2,
+        },
+      ],
+      "output": "export function greet() {
+  console.log("hello world");
+}
+
+format(reallyLongArg(), anotherLongArg());
+",
+    },
+  ],
+}
+`;
+
 exports[`should load oxfmt.config.ts 1`] = `
 {
   "fixture": "ts-config",

tests/__snapshots__/eslint-plugin.test.ts.snap

@@ -322,6 +322,14 @@ const CONFIG_LOADER_FIXTURES = [
     cwd: resolve('tests/fixtures/config-loading/jsonc'),
     title: 'should load .oxfmtrc.jsonc',
   },
+  {
+    cwd: resolve('tests/fixtures/config-loading/jsonc-trailing-comma'),
+    title: 'should load .oxfmtrc.jsonc with trailing comma',
+  },
+  {
+    cwd: resolve('tests/fixtures/config-loading/jsonc-empty'),
+    title: 'should load empty .oxfmtrc.jsonc',
+  },
   {
     cwd: resolve('tests/fixtures/config-loading/ts-config'),
     title: 'should load oxfmt.config.ts',

tests/eslint-plugin.test.ts

@@ -0,0 +1,5 @@
+export function greet() {
+    console.log("hello world");
+}
+
+format(reallyLongArg(), anotherLongArg());

tests/fixtures/config-loading/jsonc-empty/.oxfmtrc.jsonc

@@ -0,0 +1,8 @@
+{
+  // regression: load-oxfmt-config should accept trailing commas in JSONC.
+  "insertFinalNewline": false,
+  "printWidth": 24,
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+}

tests/fixtures/config-loading/jsonc-empty/src/example.js

@@ -0,0 +1,5 @@
+export function greet() {
+    console.log("hello world");
+}
+
+format(reallyLongArg(), anotherLongArg());