Fix JSONC filenames list

changelog_unreleased/json/15947.md

@@ -0,0 +1,14 @@
+#### Fix incorrect parser inference (#15947 by @fisker)
+
+Files like `.eslintrc.json` were incorrectly formatted as JSONC files.
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+prettier --file-info .eslintrc.json
+{ "ignored": false, "inferredParser": "jsonc" }
+
+// Prettier main
+prettier --file-info .eslintrc.json
+{ "ignored": false, "inferredParser": "json" }
+```

cspell.json

@@ -156,6 +156,7 @@
         "jscodeshift",
         "jsesc",
         "jsfmt",
+        "jslintrc",
         "jsonata",
         "judgements",
         "kalmanb",

src/language-json/languages.evaluate.js

@@ -14,10 +14,26 @@ const languages = [
     parsers: ["json"],
     vscodeLanguageIds: ["json"],
     extensions: data.extensions.filter((extension) => extension !== ".jsonl"),
+    filenames: [
+      ...data.filenames,
+      ".babelrc",
+      ".jscsrc",
+      ".jshintrc",
+      ".jslintrc",
+      ".swcrc",
+    ],
   })),
   createLanguage(linguistLanguages["JSON with Comments"], () => ({
     parsers: ["jsonc"],
     vscodeLanguageIds: ["jsonc"],
+    // Too many filenames from `linguist-languages` are not a valid JSONC files.
+    // https://github.com/prettier/prettier/issues/15945#issuecomment-1895371835
+    filenames: [
+      "devcontainer.json",
+      "jsconfig.json",
+      "language-configuration.json",
+      "tsconfig.json",
+    ],
   })),
   createLanguage(linguistLanguages.JSON5, () => ({
     parsers: ["json5"],

tests/integration/__tests__/__snapshots__/support-info.js.snap

@@ -488,7 +488,12 @@ exports[`CLI --support-info (stdout) 1`] = `
         "Pipfile.lock",
         "composer.lock",
         "flake.lock",
-        "mcmod.info"
+        "mcmod.info",
+        ".babelrc",
+        ".jscsrc",
+        ".jshintrc",
+        ".jslintrc",
+        ".swcrc"
       ],
       "linguistLanguageId": 174,
       "name": "JSON",
@@ -522,19 +527,10 @@ exports[`CLI --support-info (stdout) 1`] = `
         ".sublime_session"
       ],
       "filenames": [
-        ".babelrc",
-        ".devcontainer.json",
-        ".eslintrc.json",
-        ".jscsrc",
-        ".jshintrc",
-        ".jslintrc",
-        ".swcrc",
-        "api-extractor.json",
         "devcontainer.json",
         "jsconfig.json",
         "language-configuration.json",
-        "tsconfig.json",
-        "tslint.json"
+        "tsconfig.json"
       ],
       "group": "JSON",
       "linguistLanguageId": 423,

tests/integration/__tests__/with-parser-inference.js

@@ -66,8 +66,8 @@ describe("infers parser from filename", () => {
         {
           "jsc": {
             // Requires v1.2.50 or upper and requires target to be es2016 or upper.
-            "keepClassNames": false,
-          },
+            "keepClassNames": false
+          }
         }
       ` + "\n",
     );