--- /dev/null
+/**
+ * @fileoverview Rule to flag comparisons to null without a type-checking
+ * operator.
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "disallow `null` comparisons without type-checking operators",
+ category: "Best Practices",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/no-eq-null"
+ },
+
+ schema: [],
+
+ messages: {
+ unexpected: "Use '===' to compare with null."
+ }
+ },
+
+ create(context) {
+
+ return {
+
+ BinaryExpression(node) {
+ const badOperator = node.operator === "==" || node.operator === "!=";
+
+ if (node.right.type === "Literal" && node.right.raw === "null" && badOperator ||
+ node.left.type === "Literal" && node.left.raw === "null" && badOperator) {
+ context.report({ node, messageId: "unexpected" });
+ }
+ }
+ };
+
+ }
+};