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node_modules/eslint-plugin-react/lib/util/defaultProps.js

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+/**
+ * @fileoverview Common defaultProps detection functionality.
+ */
+
+'use strict';
+
+const fromEntries = require('object.fromentries');
+const astUtil = require('./ast');
+const componentUtil = require('./componentUtil');
+const propsUtil = require('./props');
+const variableUtil = require('./variable');
+const propWrapperUtil = require('./propWrapper');
+const getText = require('./eslint').getText;
+
+const QUOTES_REGEX = /^["']|["']$/g;
+
+module.exports = function defaultPropsInstructions(context, components, utils) {
+  /**
+   * Try to resolve the node passed in to a variable in the current scope. If the node passed in is not
+   * an Identifier, then the node is simply returned.
+   * @param   {ASTNode} node The node to resolve.
+   * @returns {ASTNode|null} Return null if the value could not be resolved, ASTNode otherwise.
+   */
+  function resolveNodeValue(node) {
+    if (node.type === 'Identifier') {
+      return variableUtil.findVariableByName(context, node, node.name);
+    }
+    if (
+      astUtil.isCallExpression(node)
+      && propWrapperUtil.isPropWrapperFunction(context, node.callee.name)
+      && node.arguments && node.arguments[0]
+    ) {
+      return resolveNodeValue(node.arguments[0]);
+    }
+    return node;
+  }
+
+  /**
+   * Extracts a DefaultProp from an ObjectExpression node.
+   * @param   {ASTNode} objectExpression ObjectExpression node.
+   * @returns {Object|string}            Object representation of a defaultProp, to be consumed by
+   *                                     `addDefaultPropsToComponent`, or string "unresolved", if the defaultProps
+   *                                     from this ObjectExpression can't be resolved.
+   */
+  function getDefaultPropsFromObjectExpression(objectExpression) {
+    const hasSpread = objectExpression.properties.find((property) => property.type === 'ExperimentalSpreadProperty' || property.type === 'SpreadElement');
+
+    if (hasSpread) {
+      return 'unresolved';
+    }
+
+    return objectExpression.properties.map((defaultProp) => ({
+      name: getText(context, defaultProp.key).replace(QUOTES_REGEX, ''),
+      node: defaultProp,
+    }));
+  }
+
+  /**
+   * Marks a component's DefaultProps declaration as "unresolved". A component's DefaultProps is
+   * marked as "unresolved" if we cannot safely infer the values of its defaultProps declarations
+   * without risking false negatives.
+   * @param   {Object} component The component to mark.
+   * @returns {void}
+   */
+  function markDefaultPropsAsUnresolved(component) {
+    components.set(component.node, {
+      defaultProps: 'unresolved',
+    });
+  }
+
+  /**
+   * Adds defaultProps to the component passed in.
+   * @param   {ASTNode}         component    The component to add the defaultProps to.
+   * @param   {Object[]|'unresolved'} defaultProps defaultProps to add to the component or the string "unresolved"
+   *                                         if this component has defaultProps that can't be resolved.
+   * @returns {void}
+   */
+  function addDefaultPropsToComponent(component, defaultProps) {
+    // Early return if this component's defaultProps is already marked as "unresolved".
+    if (component.defaultProps === 'unresolved') {
+      return;
+    }
+
+    if (defaultProps === 'unresolved') {
+      markDefaultPropsAsUnresolved(component);
+      return;
+    }
+
+    const defaults = component.defaultProps || {};
+    const newDefaultProps = Object.assign(
+      {},
+      defaults,
+      fromEntries(defaultProps.map((prop) => [prop.name, prop]))
+    );
+
+    components.set(component.node, {
+      defaultProps: newDefaultProps,
+    });
+  }
+
+  return {
+    MemberExpression(node) {
+      const isDefaultProp = propsUtil.isDefaultPropsDeclaration(node);
+
+      if (!isDefaultProp) {
+        return;
+      }
+
+      // find component this defaultProps belongs to
+      const component = utils.getRelatedComponent(node);
+      if (!component) {
+        return;
+      }
+
+      // e.g.:
+      // MyComponent.propTypes = {
+      //   foo: React.PropTypes.string.isRequired,
+      //   bar: React.PropTypes.string
+      // };
+      //
+      // or:
+      //
+      // MyComponent.propTypes = myPropTypes;
+      if (node.parent.type === 'AssignmentExpression') {
+        const expression = resolveNodeValue(node.parent.right);
+        if (!expression || expression.type !== 'ObjectExpression') {
+          // If a value can't be found, we mark the defaultProps declaration as "unresolved", because
+          // we should ignore this component and not report any errors for it, to avoid false-positives
+          // with e.g. external defaultProps declarations.
+          if (isDefaultProp) {
+            markDefaultPropsAsUnresolved(component);
+          }
+
+          return;
+        }
+
+        addDefaultPropsToComponent(component, getDefaultPropsFromObjectExpression(expression));
+
+        return;
+      }
+
+      // e.g.:
+      // MyComponent.propTypes.baz = React.PropTypes.string;
+      if (node.parent.type === 'MemberExpression' && node.parent.parent
+        && node.parent.parent.type === 'AssignmentExpression') {
+        addDefaultPropsToComponent(component, [{
+          name: node.parent.property.name,
+          node: node.parent.parent,
+        }]);
+      }
+    },
+
+    // e.g.:
+    // class Hello extends React.Component {
+    //   static get defaultProps() {
+    //     return {
+    //       name: 'Dean'
+    //     };
+    //   }
+    //   render() {
+    //     return <div>Hello {this.props.name}</div>;
+    //   }
+    // }
+    MethodDefinition(node) {
+      if (!node.static || node.kind !== 'get') {
+        return;
+      }
+
+      if (!propsUtil.isDefaultPropsDeclaration(node)) {
+        return;
+      }
+
+      // find component this propTypes/defaultProps belongs to
+      const component = components.get(componentUtil.getParentES6Component(context, node));
+      if (!component) {
+        return;
+      }
+
+      const returnStatement = utils.findReturnStatement(node);
+      if (!returnStatement) {
+        return;
+      }
+
+      const expression = resolveNodeValue(returnStatement.argument);
+      if (!expression || expression.type !== 'ObjectExpression') {
+        return;
+      }
+
+      addDefaultPropsToComponent(component, getDefaultPropsFromObjectExpression(expression));
+    },
+
+    // e.g.:
+    // class Greeting extends React.Component {
+    //   render() {
+    //     return (
+    //       <h1>Hello, {this.props.foo} {this.props.bar}</h1>
+    //     );
+    //   }
+    //   static defaultProps = {
+    //     foo: 'bar',
+    //     bar: 'baz'
+    //   };
+    // }
+    'ClassProperty, PropertyDefinition'(node) {
+      if (!(node.static && node.value)) {
+        return;
+      }
+
+      const propName = astUtil.getPropertyName(node);
+      const isDefaultProp = propName === 'defaultProps' || propName === 'getDefaultProps';
+
+      if (!isDefaultProp) {
+        return;
+      }
+
+      // find component this propTypes/defaultProps belongs to
+      const component = components.get(componentUtil.getParentES6Component(context, node));
+      if (!component) {
+        return;
+      }
+
+      const expression = resolveNodeValue(node.value);
+      if (!expression || expression.type !== 'ObjectExpression') {
+        return;
+      }
+
+      addDefaultPropsToComponent(component, getDefaultPropsFromObjectExpression(expression));
+    },
+
+    // e.g.:
+    // React.createClass({
+    //   render: function() {
+    //     return <div>{this.props.foo}</div>;
+    //   },
+    //   getDefaultProps: function() {
+    //     return {
+    //       foo: 'default'
+    //     };
+    //   }
+    // });
+    ObjectExpression(node) {
+      // find component this propTypes/defaultProps belongs to
+      const component = componentUtil.isES5Component(node, context) && components.get(node);
+      if (!component) {
+        return;
+      }
+
+      // Search for the proptypes declaration
+      node.properties.forEach((property) => {
+        if (property.type === 'ExperimentalSpreadProperty' || property.type === 'SpreadElement') {
+          return;
+        }
+
+        const isDefaultProp = propsUtil.isDefaultPropsDeclaration(property);
+
+        if (isDefaultProp && property.value.type === 'FunctionExpression') {
+          const returnStatement = utils.findReturnStatement(property);
+          if (!returnStatement || returnStatement.argument.type !== 'ObjectExpression') {
+            return;
+          }
+
+          addDefaultPropsToComponent(component, getDefaultPropsFromObjectExpression(returnStatement.argument));
+        }
+      });
+    },
+  };
+};