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node_modules/eslint-plugin-react/lib/rules/prefer-read-only-props.js

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+/**
+ * @fileoverview Require component props to be typed as read-only.
+ * @author Luke Zapart
+ */
+
+'use strict';
+
+const flatMap = require('array.prototype.flatmap');
+const values = require('object.values');
+
+const Components = require('../util/Components');
+const docsUrl = require('../util/docsUrl');
+const report = require('../util/report');
+
+function isFlowPropertyType(node) {
+  return node.type === 'ObjectTypeProperty';
+}
+
+function isTypescriptPropertyType(node) {
+  return node.type === 'TSPropertySignature';
+}
+
+function isCovariant(node) {
+  return (node.variance && node.variance.kind === 'plus')
+    || (
+      node.parent
+      && node.parent.parent
+      && node.parent.parent.parent
+      && node.parent.parent.parent.id
+      && node.parent.parent.parent.id.name === '$ReadOnly'
+    );
+}
+
+function isReadonly(node) {
+  return (
+    node.typeAnnotation
+    && node.typeAnnotation.parent
+    && node.typeAnnotation.parent.readonly
+  );
+}
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+const messages = {
+  readOnlyProp: 'Prop \'{{name}}\' should be read-only.',
+};
+
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Enforce that props are read-only',
+      category: 'Stylistic Issues',
+      recommended: false,
+      url: docsUrl('prefer-read-only-props'),
+    },
+    fixable: 'code',
+
+    messages,
+
+    schema: [],
+  },
+
+  create: Components.detect((context, components) => {
+    function reportReadOnlyProp(prop, propName, fixer) {
+      report(context, messages.readOnlyProp, 'readOnlyProp', {
+        node: prop.node,
+        data: {
+          name: propName,
+        },
+        fix: fixer,
+      });
+    }
+
+    return {
+      'Program:exit'() {
+        flatMap(
+          values(components.list()),
+          (component) => component.declaredPropTypes || []
+        ).forEach((declaredPropTypes) => {
+          Object.keys(declaredPropTypes).forEach((propName) => {
+            const prop = declaredPropTypes[propName];
+            if (!prop.node) {
+              return;
+            }
+
+            if (isFlowPropertyType(prop.node)) {
+              if (!isCovariant(prop.node)) {
+                reportReadOnlyProp(prop, propName, (fixer) => {
+                  if (!prop.node.variance) {
+                    // Insert covariance
+                    return fixer.insertTextBefore(prop.node, '+');
+                  }
+
+                  // Replace contravariance with covariance
+                  return fixer.replaceText(prop.node.variance, '+');
+                });
+              }
+
+              return;
+            }
+
+            if (isTypescriptPropertyType(prop.node)) {
+              if (!isReadonly(prop.node)) {
+                reportReadOnlyProp(prop, propName, (fixer) => (
+                  fixer.insertTextBefore(prop.node, 'readonly ')
+                ));
+              }
+            }
+          });
+        });
+      },
+    };
+  }),
+};