website refactor

apps/website/eslint-rules/single-export-per-file.js

@@ -0,0 +1,83 @@
+/**
+ * ESLint rule to enforce single export per file
+ * 
+ * Each file should export exactly one named export (or default export).
+ * This ensures clear, focused modules.
+ */
+
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'Enforce single export per file',
+      category: 'Best Practices',
+      recommended: true,
+    },
+    fixable: null,
+    schema: [],
+    messages: {
+      multipleExports: 'File should have exactly one export. Found {{count}} exports: {{exports}}',
+      noExports: 'File should have at least one export',
+    },
+  },
+
+  create(context) {
+    let exportCount = 0;
+    const exportNames = [];
+
+    return {
+      // Track named exports
+      ExportNamedDeclaration(node) {
+        if (node.declaration) {
+          // Exporting a class, function, const, etc.
+          if (node.declaration.id) {
+            exportCount++;
+            exportNames.push(node.declaration.id.name);
+          } else if (node.declaration.declarations) {
+            // Multiple const exports
+            node.declaration.declarations.forEach(decl => {
+              if (decl.id && decl.id.name) {
+                exportCount++;
+                exportNames.push(decl.id.name);
+              }
+            });
+          }
+        } else if (node.specifiers) {
+          // Re-exports
+          node.specifiers.forEach(spec => {
+            exportCount++;
+            exportNames.push(spec.exported.name);
+          });
+        }
+      },
+
+      // Track default exports
+      ExportDefaultDeclaration(node) {
+        exportCount++;
+        if (node.declaration && node.declaration.id) {
+          exportNames.push(`default (${node.declaration.id.name})`);
+        } else {
+          exportNames.push('default');
+        }
+      },
+
+      'Program:exit'() {
+        if (exportCount === 0) {
+          context.report({
+            node: context.getSourceCode().ast,
+            messageId: 'noExports',
+          });
+        } else if (exportCount > 1) {
+          context.report({
+            node: context.getSourceCode().ast,
+            messageId: 'multipleExports',
+            data: {
+              count: exportCount,
+              exports: exportNames.join(', '),
+            },
+          });
+        }
+      },
+    };
+  },
+};