[Refactor]: simplify utils/usedPropTypes.js

Author: golopot

lib/util/usedPropTypes.js

@@ -12,23 +12,16 @@ const ast = require('./ast');
 // Constants
 // ------------------------------------------------------------------------------
 
-const DIRECT_PROPS_REGEX = /^props\s*(\.|\[)/;
-const DIRECT_NEXT_PROPS_REGEX = /^nextProps\s*(\.|\[)/;
-const DIRECT_PREV_PROPS_REGEX = /^prevProps\s*(\.|\[)/;
 const LIFE_CYCLE_METHODS = ['componentWillReceiveProps', 'shouldComponentUpdate', 'componentWillUpdate', 'componentDidUpdate'];
 const ASYNC_SAFE_LIFE_CYCLE_METHODS = ['getDerivedStateFromProps', 'getSnapshotBeforeUpdate', 'UNSAFE_componentWillReceiveProps', 'UNSAFE_componentWillUpdate'];
 
 /**
- * Checks if a prop init name matches common naming patterns
- * @param {ASTNode} node The AST node being checked.
+ * Checks if the string is one of `props`, `nextProps`, or `prevProps`
+ * @param {string} name The AST node being checked.
  * @returns {Boolean} True if the prop name matches
  */
-function isPropAttributeName(node) {
-  return (
-    node.init.name === 'props' ||
-    node.init.name === 'nextProps' ||
-    node.init.name === 'prevProps'
-  );
+function isCommonVariableNameForProps(name) {
+  return name === 'props' || name === 'nextProps' || name === 'prevProps';
 }
 
 /**
@@ -40,26 +33,6 @@ function mustBeValidated(component) {
   return !!(component && !component.ignorePropsValidation);
 }
 
-/**
- * Check if we are in a class constructor
- * @return {boolean} true if we are in a class constructor, false if not
- */
-function inComponentWillReceiveProps(context) {
-  let scope = context.getScope();
-  while (scope) {
-    if (
-      scope.block &&
-      scope.block.parent &&
-      scope.block.parent.key &&
-      scope.block.parent.key.name === 'componentWillReceiveProps'
-    ) {
-      return true;
-    }
-    scope = scope.upper;
-  }
-  return false;
-}
-
 /**
  * Check if we are in a lifecycle method
  * @return {boolean} true if we are in a class constructor, false if not
@@ -143,7 +116,10 @@ function inSetStateUpdater(context) {
   return false;
 }
 
-function isPropArgumentInSetStateUpdater(context, node) {
+function isPropArgumentInSetStateUpdater(context, name) {
+  if (typeof name !== 'string') {
+    return;
+  }
   let scope = context.getScope();
   while (scope) {
     if (
@@ -156,13 +132,29 @@ function isPropArgumentInSetStateUpdater(context, node) {
       scope.block.parent.arguments[0].params &&
       scope.block.parent.arguments[0].params.length > 1
     ) {
-      return scope.block.parent.arguments[0].params[1].name === node.object.name;
+      return scope.block.parent.arguments[0].params[1].name === name;
     }
     scope = scope.upper;
   }
   return false;
 }
 
+function isInClassComponent(utils) {
+  return utils.getParentES6Component() || utils.getParentES5Component();
+}
+
+/**
+ * Checks if the node is `this.props`
+ * @param {ASTNode|undefined} node
+ * @returns {boolean}
+ */
+function isThisDotProps(node) {
+  return !!node &&
+    node.type === 'MemberExpression' &&
+    node.object.type === 'ThisExpression' &&
+    node.property.name === 'props';
+}
+
 /**
  * Checks if the prop has spread operator.
  * @param {ASTNode} node The AST node being marked.
@@ -178,27 +170,7 @@ function hasSpreadOperator(context, node) {
  * @param {ASTNode} node The AST node with the property.
  * @return {string|undefined} the name of the property or undefined if not found
  */
-function getPropertyName(node, context, utils, checkAsyncSafeLifeCycles) {
-  const sourceCode = context.getSourceCode();
-  const isDirectProp = DIRECT_PROPS_REGEX.test(sourceCode.getText(node));
-  const isDirectNextProp = DIRECT_NEXT_PROPS_REGEX.test(sourceCode.getText(node));
-  const isDirectPrevProp = DIRECT_PREV_PROPS_REGEX.test(sourceCode.getText(node));
-  const isDirectSetStateProp = isPropArgumentInSetStateUpdater(context, node);
-  const isInClassComponent = utils.getParentES6Component() || utils.getParentES5Component();
-  const isNotInConstructor = !utils.inConstructor(node);
-  const isNotInLifeCycleMethod = !inLifeCycleMethod(context, checkAsyncSafeLifeCycles);
-  const isNotInSetStateUpdater = !inSetStateUpdater(context);
-  if ((isDirectProp || isDirectNextProp || isDirectPrevProp || isDirectSetStateProp) &&
-    isInClassComponent &&
-    isNotInConstructor &&
-    isNotInLifeCycleMethod &&
-    isNotInSetStateUpdater
-  ) {
-    return;
-  }
-  if (!isDirectProp && !isDirectNextProp && !isDirectPrevProp && !isDirectSetStateProp) {
-    node = node.parent;
-  }
+function getPropertyName(node) {
   const property = node.property;
   if (property) {
     switch (property.type) {
@@ -225,21 +197,34 @@ function getPropertyName(node, context, utils, checkAsyncSafeLifeCycles) {
 }
 
 /**
- * Checks if we are using a prop
- * @param {ASTNode} node The AST node being checked.
- * @returns {Boolean} True if we are using a prop, false if not.
+ * Checks if the node is a propTypes usage of the form `this.props.*`, `props.*`, `prevProps.*`, or `nextProps.*`.
+ * @param {ASTNode} node
+ * @param {Context} context
+ * @param {Object} utils
+ * @param {boolean} checkAsyncSafeLifeCycles
+ * @returns {boolean}
  */
-function isPropTypesUsage(node, context, utils, checkAsyncSafeLifeCycles) {
-  const isThisPropsUsage = node.object.type === 'ThisExpression' && node.property.name === 'props';
-  const isPropsUsage = isThisPropsUsage || node.object.name === 'nextProps' || node.object.name === 'prevProps';
-  const isClassUsage = (
-    (utils.getParentES6Component() || utils.getParentES5Component()) &&
-    (isThisPropsUsage || isPropArgumentInSetStateUpdater(context, node))
-  );
-  const isStatelessFunctionUsage = node.object.name === 'props' && !ast.isAssignmentLHS(node);
-  return isClassUsage ||
-    isStatelessFunctionUsage ||
-    (isPropsUsage && inLifeCycleMethod(context, checkAsyncSafeLifeCycles));
+function isPropTypesUsageByMemberExpression(node, context, utils, checkAsyncSafeLifeCycles) {
+  if (isInClassComponent(utils)) {
+    // this.props.*
+    if (isThisDotProps(node.object)) {
+      return true;
+    }
+    // props.* or prevProps.* or nextProps.*
+    if (
+      isCommonVariableNameForProps(node.object.name) &&
+      (inLifeCycleMethod(context, checkAsyncSafeLifeCycles) || utils.inConstructor())
+    ) {
+      return true;
+    }
+    // this.setState((_, props) => props.*))
+    if (isPropArgumentInSetStateUpdater(context, node.object.name)) {
+      return true;
+    }
+    return false;
+  }
+  // props.* in function component
+  return node.object.name === 'props' && !ast.isAssignmentLHS(node);
 }
 
 module.exports = function usedPropTypesInstructions(context, components, utils) {
@@ -258,7 +243,7 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
     let properties;
     switch (node.type) {
       case 'MemberExpression':
-        name = getPropertyName(node, context, utils, checkAsyncSafeLifeCycles);
+        name = getPropertyName(node);
         if (name) {
           allNames = parentNames.concat(name);
           if (
@@ -268,16 +253,16 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
           ) {
             markPropTypesAsUsed(node.parent, allNames);
           }
+          // Handle the destructuring part of `const {foo} = props.a.b`
+          if (
+            node.parent.type === 'VariableDeclarator' &&
+            node.parent.id.type === 'ObjectPattern'
+          ) {
+            node.parent.id.parent = node.parent; // patch for bug in eslint@4 in which ObjectPattern has no parent
+            markPropTypesAsUsed(node.parent.id, allNames);
+          }
           // Do not mark computed props as used.
           type = name !== '__COMPUTED_PROP__' ? 'direct' : null;
-        } else if (
-          node.parent.id &&
-          node.parent.id.properties &&
-          node.parent.id.properties.length &&
-          ast.getKeyValue(context, node.parent.id.properties[0])
-        ) {
-          type = 'destructuring';
-          properties = node.parent.id.properties;
         }
         break;
       case 'ArrowFunctionExpression':
@@ -293,31 +278,9 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
           propParam.properties;
         break;
       }
-      case 'VariableDeclarator':
-        node.id.properties.some((property) => {
-          // let {props: {firstname}} = this
-          const thisDestructuring = (
-            property.key && (
-              (property.key.name === 'props' || property.key.value === 'props') &&
-              property.value.type === 'ObjectPattern'
-            )
-          );
-          // let {firstname} = props
-          const genericDestructuring = isPropAttributeName(node) && (
-            utils.getParentStatelessComponent() ||
-            isInLifeCycleMethod(node, checkAsyncSafeLifeCycles)
-          );
-
-          if (thisDestructuring) {
-            properties = property.value.properties;
-          } else if (genericDestructuring) {
-            properties = node.id.properties;
-          } else {
-            return false;
-          }
-          type = 'destructuring';
-          return true;
-        });
+      case 'ObjectPattern':
+        type = 'destructuring';
+        properties = node.properties;
         break;
       default:
         throw new Error(`${node.type} ASTNodes are not handled by markPropTypesAsUsed`);
@@ -334,15 +297,7 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
           break;
         }
 
-        const nodeSource = context.getSourceCode().getText(node);
-        const isDirectProp = DIRECT_PROPS_REGEX.test(nodeSource) ||
-          DIRECT_NEXT_PROPS_REGEX.test(nodeSource) ||
-          DIRECT_PREV_PROPS_REGEX.test(nodeSource);
-        const reportedNode = (
-          !isDirectProp && !utils.inConstructor() && !inComponentWillReceiveProps(context) ?
-            node.parent.property :
-            node.property
-        );
+        const reportedNode = node.property;
         usedPropTypes.push({
           name,
           allNames,
@@ -358,7 +313,8 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
           }
           const propName = ast.getKeyValue(context, properties[k]);
 
-          let currentNode = node;
+          // Get parent names in the right hand side of `const {foo} = props.a.b`
+          let currentNode = (node.parent && node.parent.init) || {};
           allNames = [];
           while (currentNode.property && currentNode.property.name !== 'props') {
             allNames.unshift(currentNode.property.name);
@@ -436,19 +392,35 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
 
   return {
     VariableDeclarator(node) {
-      const destructuring = node.init && node.id && node.id.type === 'ObjectPattern';
+      // Only handles destructuring
+      if (node.id.type !== 'ObjectPattern') {
+        return;
+      }
+
       // let {props: {firstname}} = this
-      const thisDestructuring = destructuring && node.init.type === 'ThisExpression';
-      // let {firstname} = props
-      const statelessDestructuring = destructuring && isPropAttributeName(node) && (
-        utils.getParentStatelessComponent() ||
-        isInLifeCycleMethod(node, checkAsyncSafeLifeCycles)
-      );
+      const propsProperty = node.id.properties.find(property => (
+        property.key &&
+        (property.key.name === 'props' || property.key.value === 'props') &&
+        property.value.type === 'ObjectPattern'
+      ));
+      if (propsProperty && node.init.type === 'ThisExpression') {
+        markPropTypesAsUsed(propsProperty.value);
+        return;
+      }
 
-      if (!thisDestructuring && !statelessDestructuring) {
+      // let {firstname} = props
+      if (
+        isCommonVariableNameForProps(node.init.name) &&
+        (utils.getParentStatelessComponent() || isInLifeCycleMethod(node, checkAsyncSafeLifeCycles))
+      ) {
+        markPropTypesAsUsed(node.id);
         return;
       }
-      markPropTypesAsUsed(node);
+
+      // let {firstname} = this.props
+      if (isThisDotProps(node.init) && isInClassComponent(utils)) {
+        markPropTypesAsUsed(node.id);
+      }
     },
 
     FunctionDeclaration: handleFunctionLikeExpressions,
@@ -465,7 +437,7 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
     },
 
     MemberExpression(node) {
-      if (isPropTypesUsage(node, context, utils, checkAsyncSafeLifeCycles)) {
+      if (isPropTypesUsageByMemberExpression(node, context, utils, checkAsyncSafeLifeCycles)) {
         markPropTypesAsUsed(node);
       }
     },