scripts/project-lint.ts

@@ -1,6 +1,6 @@
 /**
  * `project` — lint rules this repository holds its own source to, on top of
- * the Oxlint categories in `vite.config.ts`. Its rules of its own are `no-disable-comments` and `no-non-ts-imports`.
+ * the Oxlint categories in `vite.config.ts`. Its rules of its own are `no-disable-comments` and `no-asset-imports`.
  *
  * Loaded by `vite.config.ts` as an Oxlint `jsPlugins` entry.
  *
@@ -8,7 +8,7 @@
  */
 
 import type { LanguageOptions, RuleDefinition, RuleVisitor, TextSourceCode } from "@eslint/core";
-import type { TSESTree } from "@typescript-eslint/types";
+import { AST_NODE_TYPES, type TSESTree } from "@typescript-eslint/types";
 import type { DummyRuleMap } from "vite-plus/lint";
 
 /** The source code both hosts hand a rule, with the comment list. */
@@ -70,12 +70,16 @@ const noDisableCommentsRule: ProjectRule = {
 /** A module specifier read as a path: relative, absolute, or a `#` alias. */
 const PATH_SPECIFIER_PATTERN: RegExp = /^[./#]/u;
 
+/** Script module extensions an import may name: our `.ts` files and `.js` package subpaths. */
+const SCRIPT_EXTENSIONS: readonly string[] = [".ts", ".js"];
+
 /**
- * Whether `source` names something other than a `.ts` module: a query string
- * such as `?raw`, or a final path segment with any other extension. Bare
- * package names are left alone, dots and all, as are extensionless paths.
+ * Whether `source` names an asset rather than a script module: a query string
+ * such as `?raw`, or a final path segment with an extension other than `.ts`
+ * or `.js`. Bare package names are left alone, dots and all, as are
+ * extensionless paths.
  */
-function isNonTsSource(source: string): boolean {
+function isAssetSource(source: string): boolean {
   if (source.includes("?")) {
     return true;
   }
@@ -90,30 +94,31 @@ function isNonTsSource(source: string): boolean {
   if (lastSegment === "." || lastSegment === ".." || !lastSegment.includes(".")) {
     return false;
   }
-  return !lastSegment.endsWith(".ts");
+  return !SCRIPT_EXTENSIONS.some((extension: string): boolean => lastSegment.endsWith(extension));
 }
 
 /**
- * `no-non-ts-imports` — rejects importing anything but a `.ts` module: a
+ * `no-asset-imports` — rejects importing anything but a script module: a
  * source path, static or a dynamic `import()` with a string literal, ending in
- * another extension (`.css`, `.json`, `.svg`, `.js`, `.tsx`) or carrying a
- * query string (`?raw`, `?url`), and any import or export with import
- * attributes. Bare package names, `#` aliases, and `node:` builtins without an
- * extension pass; package subpaths are checked like paths.
+ * an extension other than `.ts` or `.js` (`.css`, `.json`, `.svg`, `.tsx`) or
+ * carrying a query string (`?raw`, `?url`), and any import or export with
+ * import attributes. `.js` covers package subpaths such as
+ * `lit/decorators.js`. Bare package names, `#` aliases, and `node:` builtins
+ * without an extension pass; package subpaths are checked like paths.
  */
-const noNonTsImportsRule: ProjectRule = {
+const noAssetImportsRule: ProjectRule = {
   meta: {
     type: "problem",
-    docs: { description: "Disallow importing modules other than .ts files" },
+    docs: { description: "Disallow importing assets instead of .ts or .js modules" },
     schema: [],
     messages: {
-      extension: "Only .ts modules may be imported.",
+      extension: "Only .ts and .js modules may be imported.",
       attributes: "Import attributes are not allowed.",
     },
   },
   create(context) {
     function checkSource(source: TSESTree.StringLiteral): void {
-      if (isNonTsSource(source.value)) {
+      if (isAssetSource(source.value)) {
         context.report({ node: source, messageId: "extension" });
       }
     }
@@ -136,7 +141,7 @@ const noNonTsImportsRule: ProjectRule = {
       ExportNamedDeclaration: checkDeclaration,
       ExportAllDeclaration: checkDeclaration,
       ImportExpression(node: TSESTree.ImportExpression): void {
-        if (node.source.type === "Literal" && typeof node.source.value === "string") {
+        if (node.source.type === AST_NODE_TYPES.Literal && typeof node.source.value === "string") {
           checkSource(node.source);
         }
         if (node.options !== null) {
@@ -203,7 +208,7 @@ const rules: DummyRuleMap = {
   "typescript/no-non-null-assertion": "error",
   // No disable comments at all.
   "project/no-disable-comments": "error",
-  "project/no-non-ts-imports": "error",
+  "project/no-asset-imports": "error",
   "unicorn/no-abusive-eslint-disable": "error",
   // Pedantic, but Node's and the web's own types (`Response`, `Stats`,
   // `RequestInit`) are mutable, so no parameter of theirs can pass; the
@@ -219,7 +224,7 @@ const plugin = {
   meta: { name: "project" },
   rules: {
     "no-disable-comments": noDisableCommentsRule,
-    "no-non-ts-imports": noNonTsImportsRule,
+    "no-asset-imports": noAssetImportsRule,
   },
   configs: { project: { rules } },
 };