Initial commit

packages/core-eslint/rules/atomic-tier-import-direction.js

@@ -0,0 +1,47 @@
+const TIERS = ["atoms", "molecules", "organisms", "templates", "pages"];
+
+function tierOf(filepath) {
+  for (let i = 0; i < TIERS.length; i++) {
+    const tier = TIERS[i];
+    if (filepath.includes(`/${tier}/`) || filepath.includes(`\\${tier}\\`)) {
+      return { name: tier, index: i };
+    }
+  }
+  return null;
+}
+
+/** @type {import("eslint").Rule.RuleModule} */
+export default {
+  meta: {
+    type: "problem",
+    docs: {
+      description:
+        "Atomic-design tier imports respect direction: atoms ← molecules ← organisms ← templates ← pages.",
+    },
+    schema: [],
+    messages: {
+      wrongDirection:
+        "{{fromTier}} cannot import from {{toTier}} ({{importPath}}). Tier direction: atoms ← molecules ← organisms ← templates ← pages.",
+    },
+  },
+  create(context) {
+    const filename = context.filename;
+    const from = tierOf(filename);
+    if (!from) return {};
+    return {
+      ImportDeclaration(node) {
+        const source = node.source.value;
+        if (typeof source !== "string") return;
+        const to = tierOf(source);
+        if (!to) return;
+        if (to.index > from.index) {
+          context.report({
+            node,
+            messageId: "wrongDirection",
+            data: { fromTier: from.name, toTier: to.name, importPath: source },
+          });
+        }
+      },
+    };
+  },
+};