feat(linter): inherit rules via the extended config files (#9308)

- part of #9307

This gives the `extends` keyword some functionality: specifically to allow inheriting rules from other configuration files. Rules that are in the extended configuration will be used as the base, and then files in the config doing the extending will override the extended rules.

So, you can, for example, specify a base configuration that defines rules that you generally want to be enabled. Then, in each nested configuration file, you could disable rules depending on the directory:

```text
.oxlintrc.json       // { "rules: { "no-useless-escape": "error" } }
package1/
  .oxlintrc.json     // { "extends": ["../.oxlintrc.json"], "rules": { "no-useless-escape": "off" } }
package2/
  src                // uses ../.oxlintrc.json with `no-useless-escape` enabled
```

As a side effect of this, building a config from a `.oxlintrc.json` file can result in config errors, even if all of the syntax and rules are configured correctly, because an extended configuration file might be incorrect or unparseable. For now, we simply raise an error if this occurs and stop execution, but in the future we could make this more graceful if we wanted and just ignore that file.

We will also need to revisit performance here, as I think a global cache config might be necessary so that we never load a file more than once and parse it more than once.

Author: camchenry

apps/oxlint/fixtures/extends_config/console.js

@@ -0,0 +1 @@
+console.log("test");

apps/oxlint/fixtures/extends_config/empty_config.json

@@ -0,0 +1 @@
+{}

apps/oxlint/fixtures/extends_config/extends_invalid_config.json

@@ -0,0 +1,3 @@
+{
+  "extends": ["./invalid_config.json"]
+}

apps/oxlint/fixtures/extends_config/extends_rules_config.json

@@ -0,0 +1,3 @@
+{
+  "extends": ["./rules_config.json"]
+}

apps/oxlint/fixtures/extends_config/invalid_config.json

@@ -0,0 +1,3 @@
+{
+  invalid
+}

apps/oxlint/fixtures/extends_config/rules_config.json

@@ -0,0 +1,7 @@
+{
+  "rules": {
+    "no-debugger": "off",
+    "no-console": "error",
+    "unicorn/no-null": "error"
+  }
+}

apps/oxlint/fixtures/extends_config/rules_multiple/allow_all.json

@@ -0,0 +1,9 @@
+{
+  "rules": {
+    "no-console": "off",
+    "no-var": "off",
+    "oxc/approx-constant": "off",
+    "unicorn/no-null": "off",
+    "unicorn/no-array-for-each": "off"
+  }
+}

apps/oxlint/fixtures/extends_config/rules_multiple/deny_all.json

@@ -0,0 +1,9 @@
+{
+  "rules": {
+    "no-console": "error",
+    "no-var": "error",
+    "oxc/approx-constant": "error",
+    "unicorn/no-null": "error",
+    "unicorn/no-array-for-each": "error"
+  }
+}

apps/oxlint/fixtures/extends_config/rules_multiple/warn_all.json

@@ -0,0 +1,9 @@
+{
+  "rules": {
+    "no-console": "warn",
+    "no-var": "warn",
+    "oxc/approx-constant": "warn",
+    "unicorn/no-null": "warn",
+    "unicorn/no-array-for-each": "warn"
+  }
+}

apps/oxlint/src/lint.rs

@@ -7,7 +7,7 @@ use std::{
 
 use cow_utils::CowUtils;
 use ignore::{gitignore::Gitignore, overrides::OverrideBuilder};
-use oxc_diagnostics::{DiagnosticService, GraphicalReportHandler};
+use oxc_diagnostics::{DiagnosticService, GraphicalReportHandler, OxcDiagnostic};
 use oxc_linter::{
     AllowWarnDeny, ConfigStore, ConfigStoreBuilder, InvalidFilterKind, LintFilter, LintOptions,
     LintService, LintServiceOptions, Linter, Oxlintrc, loader::LINT_PARTIAL_LOADER_EXT,
@@ -200,9 +200,28 @@ impl Runner for LintRunner {
 
             // iterate over each config and build the ConfigStore
             for (dir, oxlintrc) in nested_oxlintrc {
+                // TODO(refactor): clean up all of the error handling in this function
+                let builder = match ConfigStoreBuilder::from_oxlintrc(false, oxlintrc) {
+                    Ok(builder) => builder,
+                    Err(e) => {
+                        let handler = GraphicalReportHandler::new();
+                        let mut err = String::new();
+                        handler
+                            .render_report(&mut err, &OxcDiagnostic::error(e.to_string()))
+                            .unwrap();
+                        stdout
+                            .write_all(
+                                format!("Failed to parse configuration file.\n{err}\n").as_bytes(),
+                            )
+                            .or_else(Self::check_for_writer_error)
+                            .unwrap();
+                        stdout.flush().unwrap();
+
+                        return CliRunResult::InvalidOptionConfig;
+                    }
+                }
                 // TODO(perf): figure out if we can avoid cloning `filter`
-                let builder =
-                    ConfigStoreBuilder::from_oxlintrc(false, oxlintrc).with_filters(filter.clone());
+                .with_filters(filter.clone());
                 match builder.build() {
                     Ok(config) => nested_configs.insert(dir.to_path_buf(), config),
                     Err(diagnostic) => {
@@ -230,8 +249,22 @@ impl Runner for LintRunner {
         } else {
             None
         };
-        let config_builder =
-            ConfigStoreBuilder::from_oxlintrc(false, oxlintrc).with_filters(filter);
+        let config_builder = match ConfigStoreBuilder::from_oxlintrc(false, oxlintrc) {
+            Ok(builder) => builder,
+            Err(e) => {
+                let handler = GraphicalReportHandler::new();
+                let mut err = String::new();
+                handler.render_report(&mut err, &OxcDiagnostic::error(e.to_string())).unwrap();
+                stdout
+                    .write_all(format!("Failed to parse configuration file.\n{err}\n").as_bytes())
+                    .or_else(Self::check_for_writer_error)
+                    .unwrap();
+                stdout.flush().unwrap();
+
+                return CliRunResult::InvalidOptionConfig;
+            }
+        }
+        .with_filters(filter);
 
         if let Some(basic_config_file) = oxlintrc_for_print {
             let config_file = config_builder.resolve_final_config_file(basic_config_file);
@@ -982,4 +1015,11 @@ mod test {
         ];
         Tester::new().with_cwd("fixtures/nested_config".into()).test_and_snapshot(args);
     }
+
+    #[test]
+    fn test_extends_explicit_config() {
+        // Check that referencing a config file that extends other config files works as expected
+        let args = &["--config", "extends_rules_config.json", "console.js"];
+        Tester::new().with_cwd("fixtures/extends_config".into()).test_and_snapshot(args);
+    }
 }

apps/oxlint/src/snapshots/fixtures__extends_config_--config extends_rules_config.json console.js@oxlint.snap

@@ -0,0 +1,20 @@
+---
+source: apps/oxlint/src/tester.rs
+---
+########## 
+arguments: --config extends_rules_config.json console.js
+working directory: fixtures/extends_config
+----------
+
+  x ]8;;https://oxc.rs/docs/guide/usage/linter/rules/eslint/no-console.html\eslint(no-console)]8;;\: eslint(no-console): Unexpected console statement.
+   ,-[console.js:1:1]
+ 1 | console.log("test");
+   : ^^^^^^^^^^^
+   `----
+  help: Delete this console statement.
+
+Found 0 warnings and 1 error.
+Finished in <variable>ms on 1 file with 101 rules using 1 threads.
+----------
+CLI result: LintFoundErrors
+----------

crates/oxc_language_server/src/main.rs

@@ -497,6 +497,7 @@ impl Backend {
             let config = Oxlintrc::from_file(&config_path)
                 .expect("should have initialized linter with new options");
             let config_store = ConfigStoreBuilder::from_oxlintrc(true, config.clone())
+                .expect("failed to build config")
                 .build()
                 .expect("failed to build config");
             *linter = ServerLinter::new_with_linter(