fix(linter/plugins): report error when two plugins are aliased to the same name

apps/oxlint/test/fixtures/plugin_name_duplicate_alias/.oxlintrc.json

@@ -0,0 +1,7 @@
+{
+  "jsPlugins": [
+    { "name": "custom", "specifier": "./plugin1.ts" },
+    { "name": "custom", "specifier": "./plugin2.ts" }
+  ],
+  "rules": {}
+}

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

@@ -0,0 +1 @@
+const x = 1;

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

@@ -0,0 +1,25 @@
+# Exit code
+1
+
+# stdout
+```
+Failed to parse configuration file.
+
+  x Plugin name 'custom' is already in use.
+  | 
+  | Multiple plugins cannot share the same name or alias.
+  | Each plugin must have a unique identifier to avoid conflicts.
+  | 
+  | Please provide a different alias for one of the plugins:
+  | 
+  | "jsPlugins": [
+  |   { "name": "custom", "specifier": "plugin-one" },
+  |   { "name": "custom-alt", "specifier": "plugin-two" }
+  | ]
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```

apps/oxlint/test/fixtures/plugin_name_duplicate_alias/plugin1.ts

@@ -0,0 +1,19 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "first-plugin",
+  },
+  rules: {
+    "rule-one": {
+      meta: {
+        type: "problem",
+      },
+      create(context) {
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;

apps/oxlint/test/fixtures/plugin_name_duplicate_alias/plugin2.ts

@@ -0,0 +1,19 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "second-plugin",
+  },
+  rules: {
+    "rule-two": {
+      meta: {
+        type: "problem",
+      },
+      create(context) {
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;

apps/oxlint/test/fixtures/plugin_name_duplicate_no_alias_then_alias/.oxlintrc.json

@@ -0,0 +1,7 @@
+{
+  "jsPlugins": [
+    "./plugin.ts",
+    { "name": "foo", "specifier": "./other.ts" }
+  ],
+  "rules": {}
+}

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

@@ -0,0 +1 @@
+const x = 1;

apps/oxlint/test/fixtures/plugin_name_duplicate_no_alias_then_alias/other.ts

@@ -0,0 +1,10 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "other-plugin",
+  },
+  rules: {},
+};
+
+export default plugin;

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

@@ -0,0 +1,25 @@
+# Exit code
+1
+
+# stdout
+```
+Failed to parse configuration file.
+
+  x Plugin name 'foo' is already in use.
+  | 
+  | Multiple plugins cannot share the same name or alias.
+  | Each plugin must have a unique identifier to avoid conflicts.
+  | 
+  | Please provide a different alias for one of the plugins:
+  | 
+  | "jsPlugins": [
+  |   { "name": "foo", "specifier": "plugin-one" },
+  |   { "name": "foo-alt", "specifier": "plugin-two" }
+  | ]
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```

apps/oxlint/test/fixtures/plugin_name_duplicate_no_alias_then_alias/plugin.ts

@@ -0,0 +1,19 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "foo",
+  },
+  rules: {
+    "test-rule": {
+      meta: {
+        type: "problem",
+      },
+      create(context) {
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;

apps/oxlint/test/fixtures/plugin_name_duplicate_same_meta_name/.oxlintrc.json

@@ -0,0 +1,7 @@
+{
+  "jsPlugins": [
+    "./plugin1.ts",
+    "./plugin2.ts"
+  ],
+  "rules": {}
+}

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

@@ -0,0 +1 @@
+const x = 1;

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

@@ -0,0 +1,25 @@
+# Exit code
+1
+
+# stdout
+```
+Failed to parse configuration file.
+
+  x Plugin name 'shared-name' is already in use.
+  | 
+  | Multiple plugins cannot share the same name or alias.
+  | Each plugin must have a unique identifier to avoid conflicts.
+  | 
+  | Please provide a different alias for one of the plugins:
+  | 
+  | "jsPlugins": [
+  |   { "name": "shared-name", "specifier": "plugin-one" },
+  |   { "name": "shared-name-alt", "specifier": "plugin-two" }
+  | ]
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```

apps/oxlint/test/fixtures/plugin_name_duplicate_same_meta_name/plugin1.ts

@@ -0,0 +1,19 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "shared-name",
+  },
+  rules: {
+    "rule-one": {
+      meta: {
+        type: "problem",
+      },
+      create(context) {
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;

apps/oxlint/test/fixtures/plugin_name_duplicate_same_meta_name/plugin2.ts

@@ -0,0 +1,19 @@
+import type { Plugin } from "#oxlint";
+
+const plugin: Plugin = {
+  meta: {
+    name: "shared-name",
+  },
+  rules: {
+    "rule-two": {
+      meta: {
+        type: "problem",
+      },
+      create(context) {
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;

crates/oxc_linter/src/config/config_builder.rs

@@ -578,17 +578,21 @@ impl ConfigStoreBuilder {
             })?;
         let plugin_name = result.name;
 
-        if LintPlugins::try_from(plugin_name.as_str()).is_err() {
-            external_plugin_store.register_plugin(
-                plugin_path,
-                plugin_name,
-                result.offset,
-                result.rule_names,
-            );
-            Ok(())
-        } else {
-            Err(ConfigBuilderError::ReservedExternalPluginName { plugin_name })
+        if LintPlugins::try_from(plugin_name.as_str()).is_ok() {
+            return Err(ConfigBuilderError::ReservedExternalPluginName { plugin_name });
+        }
+
+        if external_plugin_store.is_plugin_name_registered(&plugin_name) {
+            return Err(ConfigBuilderError::DuplicatePluginAlias { plugin_name });
         }
+
+        external_plugin_store.register_plugin(
+            plugin_path,
+            plugin_name,
+            result.offset,
+            result.rule_names,
+        );
+        Ok(())
     }
 }
 
@@ -632,6 +636,9 @@ pub enum ConfigBuilderError {
     ReservedExternalPluginName {
         plugin_name: String,
     },
+    DuplicatePluginAlias {
+        plugin_name: String,
+    },
 }
 
 impl Display for ConfigBuilderError {
@@ -682,6 +689,23 @@ impl Display for ConfigBuilderError {
                 )?;
                 Ok(())
             }
+            ConfigBuilderError::DuplicatePluginAlias { plugin_name } => {
+                write!(
+                    f,
+                    "Plugin name '{plugin_name}' is already in use.\n\
+                     \n\
+                     Multiple plugins cannot share the same name or alias.\n\
+                     Each plugin must have a unique identifier to avoid conflicts.\n\
+                     \n\
+                     Please provide a different alias for one of the plugins:\n\
+                     \n\
+                     \"jsPlugins\": [\n  \
+                       {{ \"name\": \"{plugin_name}\", \"specifier\": \"plugin-one\" }},\n  \
+                       {{ \"name\": \"{plugin_name}-alt\", \"specifier\": \"plugin-two\" }}\n\
+                     ]",
+                )?;
+                Ok(())
+            }
             ConfigBuilderError::ExternalRuleLookupError(e) => std::fmt::Display::fmt(&e, f),
         }
     }

crates/oxc_linter/src/external_plugin_store.rs

@@ -83,6 +83,10 @@ impl ExternalPluginStore {
         self.registered_plugin_paths.contains(plugin_path)
     }
 
+    pub fn is_plugin_name_registered(&self, plugin_name: &str) -> bool {
+        self.plugin_names.contains_key(plugin_name)
+    }
+
     /// Register plugin.
     ///
     /// # Panics