feat(oxlint): Support vite.config.ts .lint field

apps/oxlint/src-js/js_config.ts

@@ -105,14 +105,19 @@ export async function loadJsConfigs(paths: string[]): Promise<string> {
           throw new Error(`Configuration file must have a default export that is an object.`);
         }
 
-        if (!isDefineConfig(config)) {
-          throw new Error(
-            `Configuration file must wrap its default export with defineConfig() from "oxlint".`,
-          );
+        // Vite config files (e.g. `vite.config.ts`) are not Oxlint configs,
+        // so skip `defineConfig()` and `extends` validation.
+        // The `.lint` field extraction is handled on the Rust side.
+        if (!path.endsWith("/vite.config.ts")) {
+          if (!isDefineConfig(config)) {
+            throw new Error(
+              `Configuration file must wrap its default export with defineConfig() from "oxlint".`,
+            );
+          }
+
+          validateConfigExtends(config as object);
         }
 
-        validateConfigExtends(config as object);
-
         return { path, config };
       }),
     );

apps/oxlint/src/config_loader.rs

@@ -12,7 +12,9 @@ use oxc_linter::{
 };
 use rustc_hash::{FxBuildHasher, FxHashMap, FxHashSet};
 
-use crate::{DEFAULT_JSONC_OXLINTRC_NAME, DEFAULT_OXLINTRC_NAME, DEFAULT_TS_OXLINTRC_NAME};
+use crate::{
+    DEFAULT_JSONC_OXLINTRC_NAME, DEFAULT_OXLINTRC_NAME, DEFAULT_TS_OXLINTRC_NAME, VITE_CONFIG_NAME,
+};
 
 #[cfg(feature = "napi")]
 use crate::js_config;
@@ -487,6 +489,12 @@ impl<'a> ConfigLoader<'a> {
             return Oxlintrc::from_file(&jsonc_path).map(Some);
         }
 
+        // Fallback: check for vite.config.ts with .lint field (lowest priority)
+        let vite_path = dir.join(VITE_CONFIG_NAME);
+        if vite_path.is_file() {
+            return self.load_root_js_config(&vite_path).map(Some);
+        }
+
         Ok(None)
     }
 

apps/oxlint/src/js_config.rs

@@ -5,6 +5,7 @@ use oxc_diagnostics::OxcDiagnostic;
 use oxc_linter::Oxlintrc;
 
 use crate::run::JsLoadJsConfigsCb;
+use crate::{VITE_CONFIG_NAME, VITE_OXLINT_CONFIG_FIELD};
 
 /// Callback type for loading JavaScript/TypeScript config files.
 pub type JsConfigLoaderCb =
@@ -118,7 +119,27 @@ fn parse_js_config_response(json: &str) -> Result<Vec<JsConfigResult>, Vec<OxcDi
                 (Vec::with_capacity(count), Vec::new()),
                 |(mut configs, mut errors), entry| {
                     let path = PathBuf::from(&entry.path);
-                    let mut oxlintrc = match parse_js_oxlintrc(entry.config) {
+
+                    // Vite config files: extract the `.lint` field
+                    let is_vite_config = path
+                        .file_name()
+                        .and_then(|f| f.to_str())
+                        .is_some_and(|name| name == VITE_CONFIG_NAME);
+                    let config_value = if is_vite_config {
+                        if let Some(v) = entry.config.get(VITE_OXLINT_CONFIG_FIELD).cloned() {
+                            v
+                        } else {
+                            errors.push(OxcDiagnostic::error(format!(
+                                "Expected a `{VITE_OXLINT_CONFIG_FIELD}` field in the default export of {}",
+                                entry.path
+                            )));
+                            return (configs, errors);
+                        }
+                    } else {
+                        entry.config
+                    };
+
+                    let mut oxlintrc = match parse_js_oxlintrc(config_value) {
                         Ok(config) => config,
                         Err(err) => {
                             errors.push(

apps/oxlint/src/lib.rs

@@ -59,6 +59,9 @@ static GLOBAL: mimalloc_safe::MiMalloc = mimalloc_safe::MiMalloc;
 const DEFAULT_OXLINTRC_NAME: &str = ".oxlintrc.json";
 const DEFAULT_JSONC_OXLINTRC_NAME: &str = ".oxlintrc.jsonc";
 const DEFAULT_TS_OXLINTRC_NAME: &str = "oxlint.config.ts";
+/// Vite config file that may contain oxlint config under a `.lint` field.
+const VITE_CONFIG_NAME: &str = "vite.config.ts";
+const VITE_OXLINT_CONFIG_FIELD: &str = "lint";
 
 /// Return a JSON blob containing metadata for all available oxlint rules.
 ///

apps/oxlint/src/lsp/server_linter.rs

@@ -494,6 +494,7 @@ impl Tool for ServerLinter {
                     "**/.oxlintrc.json".to_string(),
                     "**/.oxlintrc.jsonc".to_string(),
                     "**/oxlint.config.ts".to_string(),
+                    "**/vite.config.ts".to_string(),
                 ]
             }
             Some(v) => vec![v.to_string()],
@@ -1090,10 +1091,11 @@ mod test_watchers {
             let patterns =
                 Tester::new("fixtures/lsp/watchers/default", json!({})).get_watcher_patterns();
 
-            assert_eq!(patterns.len(), 3);
+            assert_eq!(patterns.len(), 4);
             assert_eq!(patterns[0], "**/.oxlintrc.json".to_string());
             assert_eq!(patterns[1], "**/.oxlintrc.jsonc".to_string());
             assert_eq!(patterns[2], "**/oxlint.config.ts".to_string());
+            assert_eq!(patterns[3], "**/vite.config.ts".to_string());
         }
 
         #[test]
@@ -1106,10 +1108,11 @@ mod test_watchers {
             )
             .get_watcher_patterns();
 
-            assert_eq!(patterns.len(), 3);
+            assert_eq!(patterns.len(), 4);
             assert_eq!(patterns[0], "**/.oxlintrc.json".to_string());
             assert_eq!(patterns[1], "**/.oxlintrc.jsonc".to_string());
             assert_eq!(patterns[2], "**/oxlint.config.ts".to_string());
+            assert_eq!(patterns[3], "**/vite.config.ts".to_string());
         }
 
         #[test]
@@ -1131,12 +1134,13 @@ mod test_watchers {
             let patterns = Tester::new("fixtures/lsp/watchers/linter_extends", json!({}))
                 .get_watcher_patterns();
 
-            // The `.oxlintrc.json` extends `./lint.json` -> 4 watchers (json, jsonc, ts, lint.json)
-            assert_eq!(patterns.len(), 4);
+            // The `.oxlintrc.json` extends `./lint.json` -> 5 watchers (json, jsonc, ts, vite, lint.json)
+            assert_eq!(patterns.len(), 5);
             assert_eq!(patterns[0], "**/.oxlintrc.json".to_string());
             assert_eq!(patterns[1], "**/.oxlintrc.jsonc".to_string());
             assert_eq!(patterns[2], "**/oxlint.config.ts".to_string());
-            assert_eq!(patterns[3], "lint.json".to_string());
+            assert_eq!(patterns[3], "**/vite.config.ts".to_string());
+            assert_eq!(patterns[4], "lint.json".to_string());
         }
 
         #[test]
@@ -1164,11 +1168,12 @@ mod test_watchers {
             )
             .get_watcher_patterns();
 
-            assert_eq!(patterns.len(), 4);
+            assert_eq!(patterns.len(), 5);
             assert_eq!(patterns[0], "**/.oxlintrc.json".to_string());
             assert_eq!(patterns[1], "**/.oxlintrc.jsonc".to_string());
             assert_eq!(patterns[2], "**/oxlint.config.ts".to_string());
-            assert_eq!(patterns[3], "**/tsconfig*.json".to_string());
+            assert_eq!(patterns[3], "**/vite.config.ts".to_string());
+            assert_eq!(patterns[4], "**/tsconfig*.json".to_string());
         }
     }
 
@@ -1219,11 +1224,12 @@ mod test_watchers {
                         "typeAware": true
                     }));
             assert!(watch_patterns.is_some());
-            assert_eq!(watch_patterns.as_ref().unwrap().len(), 4);
+            assert_eq!(watch_patterns.as_ref().unwrap().len(), 5);
             assert_eq!(watch_patterns.as_ref().unwrap()[0], "**/.oxlintrc.json".to_string());
             assert_eq!(watch_patterns.as_ref().unwrap()[1], "**/.oxlintrc.jsonc".to_string());
             assert_eq!(watch_patterns.as_ref().unwrap()[2], "**/oxlint.config.ts".to_string());
-            assert_eq!(watch_patterns.as_ref().unwrap()[3], "**/tsconfig*.json".to_string());
+            assert_eq!(watch_patterns.as_ref().unwrap()[3], "**/vite.config.ts".to_string());
+            assert_eq!(watch_patterns.as_ref().unwrap()[4], "**/tsconfig*.json".to_string());
         }
     }
 }

apps/oxlint/test/fixtures/vite_config_basic/files/test.js

@@ -0,0 +1,3 @@
+debugger;
+if (x == 1) {
+}

apps/oxlint/test/fixtures/vite_config_basic/options.json

@@ -0,0 +1,3 @@
+{
+  "singleThread": true
+}

apps/oxlint/test/fixtures/vite_config_basic/output.snap.md

@@ -0,0 +1,29 @@
+# Exit code
+1
+
+# stdout
+```
+  x eslint(no-debugger): `debugger` statement is not allowed
+   ,-[files/test.js:1:1]
+ 1 | debugger;
+   : ^^^^^^^^^
+ 2 | if (x == 1) {
+   `----
+  help: Remove the debugger statement
+
+  ! eslint(eqeqeq): Expected === and instead saw ==
+   ,-[files/test.js:2:7]
+ 1 | debugger;
+ 2 | if (x == 1) {
+   :       ^^
+ 3 | }
+   `----
+  help: Prefer === operator
+
+Found 1 warning and 1 error.
+Finished in Xms on 1 file with 94 rules using X threads.
+```
+
+# stderr
+```
+```

apps/oxlint/test/fixtures/vite_config_basic/vite.config.ts

@@ -0,0 +1,8 @@
+export default {
+  lint: {
+    rules: {
+      "no-debugger": "error",
+      eqeqeq: "warn",
+    },
+  },
+};

apps/oxlint/test/fixtures/vite_config_no_lint_field/files/test.js

@@ -0,0 +1 @@
+debugger;

apps/oxlint/test/fixtures/vite_config_no_lint_field/options.json

@@ -0,0 +1,3 @@
+{
+  "singleThread": true
+}

apps/oxlint/test/fixtures/vite_config_no_lint_field/output.snap.md

@@ -0,0 +1,13 @@
+# Exit code
+1
+
+# stdout
+```
+Failed to parse oxlint configuration file.
+
+  x Expected a `lint` field in the default export of <fixture>/vite.config.ts
+```
+
+# stderr
+```
+```

apps/oxlint/test/fixtures/vite_config_no_lint_field/vite.config.ts

@@ -0,0 +1,3 @@
+export default {
+  plugins: [],
+};

apps/oxlint/test/fixtures/vite_config_priority/files/test.js

@@ -0,0 +1,3 @@
+debugger;
+if (x == 1) {
+}

apps/oxlint/test/fixtures/vite_config_priority/options.json

@@ -0,0 +1,3 @@
+{
+  "singleThread": true
+}

apps/oxlint/test/fixtures/vite_config_priority/output.snap.md

@@ -0,0 +1,20 @@
+# Exit code
+1
+
+# stdout
+```
+  x eslint(no-debugger): `debugger` statement is not allowed
+   ,-[files/test.js:1:1]
+ 1 | debugger;
+   : ^^^^^^^^^
+ 2 | if (x == 1) {
+   `----
+  help: Remove the debugger statement
+
+Found 0 warnings and 1 error.
+Finished in Xms on 1 file with 93 rules using X threads.
+```
+
+# stderr
+```
+```

apps/oxlint/test/fixtures/vite_config_priority/oxlint.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from "#oxlint";
+
+export default defineConfig({
+  rules: {
+    "no-debugger": "error",
+  },
+});

apps/oxlint/test/fixtures/vite_config_priority/vite.config.ts

@@ -0,0 +1,7 @@
+export default {
+  lint: {
+    rules: {
+      eqeqeq: "warn",
+    },
+  },
+};

apps/oxlint/test/lsp/init/init.test.ts

@@ -37,8 +37,14 @@ describe("LSP initialization", () => {
   });
 
   it.each([
-    [undefined, ["**/.oxlintrc.json", "**/.oxlintrc.jsonc", "**/oxlint.config.ts"]],
-    [{ configPath: "" }, ["**/.oxlintrc.json", "**/.oxlintrc.jsonc", "**/oxlint.config.ts"]],
+    [
+      undefined,
+      ["**/.oxlintrc.json", "**/.oxlintrc.jsonc", "**/oxlint.config.ts", "**/vite.config.ts"],
+    ],
+    [
+      { configPath: "" },
+      ["**/.oxlintrc.json", "**/.oxlintrc.jsonc", "**/oxlint.config.ts", "**/vite.config.ts"],
+    ],
     [{ configPath: "./custom-config.json" }, ["./custom-config.json"]],
   ])(
     "should send correct dynamic watch pattern registration for config: %s",