feat(eslint): no-imports-from-self rule (#7691)

New rule to prevent a package from importing from itself.

packages/eslint-plugin/customRules/no-imports-from-self.js

@@ -0,0 +1,67 @@
+import fs from 'fs'
+import path from 'path'
+
+/** @type {import('eslint').Rule.RuleModule} */
+export const rule = {
+  meta: {
+    docs: {
+      description: 'Disallow a package from importing from itself',
+      category: 'Best Practices',
+      recommended: true,
+    },
+    fixable: 'code',
+    schema: [],
+  },
+
+  create(context) {
+    let packageName = null
+
+    return {
+      ImportDeclaration(node) {
+        const importPath = node.source.value
+        const pkgName = getPackageName(context, packageName)
+        if (pkgName && importPath.startsWith(pkgName)) {
+          context.report({
+            node,
+            message: `Package "${pkgName}" should not import from itself. Use relative instead.`,
+          })
+        }
+      },
+    }
+  },
+}
+
+export default rule
+
+/**
+ * @param {import('eslint').Rule.RuleContext} context
+ * @param {string|undefined} packageName
+ */
+function getPackageName(context, packageName) {
+  if (packageName) {
+    return packageName
+  }
+
+  const fileName = context.getFilename()
+  const pkg = findNearestPackageJson(path.dirname(fileName))
+  if (pkg) {
+    return pkg.name
+  }
+}
+
+/**
+ * @param {string} startDir
+ */
+function findNearestPackageJson(startDir) {
+  let currentDir = startDir
+  while (currentDir !== path.dirname(currentDir)) {
+    // Root directory check
+    const pkgPath = path.join(currentDir, 'package.json')
+    if (fs.existsSync(pkgPath)) {
+      const pkgContent = JSON.parse(fs.readFileSync(pkgPath, 'utf8'))
+      return pkgContent
+    }
+    currentDir = path.dirname(currentDir)
+  }
+  return null
+}