initial commit. phase 1 complete

frontend/node_modules/eslint-plugin-react/lib/rules/no-multi-comp.js

@@ -0,0 +1,81 @@
+/**
+ * @fileoverview Prevent multiple component definition per file
+ * @author Yannick Croissant
+ */
+
+'use strict';
+
+const values = require('object.values');
+
+const Components = require('../util/Components');
+const docsUrl = require('../util/docsUrl');
+const report = require('../util/report');
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+const messages = {
+  onlyOneComponent: 'Declare only one React component per file',
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Disallow multiple component definition per file',
+      category: 'Stylistic Issues',
+      recommended: false,
+      url: docsUrl('no-multi-comp'),
+    },
+
+    messages,
+
+    schema: [{
+      type: 'object',
+      properties: {
+        ignoreStateless: {
+          default: false,
+          type: 'boolean',
+        },
+      },
+      additionalProperties: false,
+    }],
+  },
+
+  create: Components.detect((context, components, utils) => {
+    const configuration = context.options[0] || {};
+    const ignoreStateless = configuration.ignoreStateless || false;
+
+    /**
+     * Checks if the component is ignored
+     * @param {Object} component The component being checked.
+     * @returns {boolean} True if the component is ignored, false if not.
+     */
+    function isIgnored(component) {
+      return (
+        ignoreStateless && (
+          /Function/.test(component.node.type)
+          || utils.isPragmaComponentWrapper(component.node)
+        )
+      );
+    }
+
+    return {
+      'Program:exit'() {
+        if (components.length() <= 1) {
+          return;
+        }
+
+        values(components.list())
+          .filter((component) => !isIgnored(component))
+          .slice(1)
+          .forEach((component) => {
+            report(context, messages.onlyOneComponent, 'onlyOneComponent', {
+              node: component.node,
+            });
+          });
+      },
+    };
+  }),
+};