Extract visit function to parsers/utils (#34946)

Summary:
This PR is a task from #34872:
> Extract the visit function in a shared function in the parsers/utils.js folder. Use the new function in the Flow and TypeScript parsers.

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[Internal] [Changed] - Extract the visit function in a shared function in the parsers/utils.js

Pull Request resolved: #34946

Test Plan: I tested using jest, flow and eslint commands.

Reviewed By: NickGerleman

Differential Revision: D40276462

Pulled By: cipolleschi

fbshipit-source-id: 299cc2a3aa65a9757b217192a13838d037c497a1

Author: Antoine Doubovetzky

packages/react-native-codegen/src/parsers/__tests__/utils-test.js

@@ -14,6 +14,7 @@
 const {
   extractNativeModuleName,
   createParserErrorCapturer,
+  visit,
 } = require('../utils.js');
 const {ParserError} = require('../errors');
 
@@ -115,3 +116,107 @@ describe('createParserErrorCapturer', () => {
     });
   });
 });
+
+describe('visit', () => {
+  describe('when the astNode is null', () => {
+    it("doesn't call the visitor function", () => {
+      const visitorFunction = jest.fn();
+      const visitor = {
+        itemType: visitorFunction,
+      };
+
+      const astNode = null;
+
+      visit(astNode, visitor);
+
+      expect(visitorFunction).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('when the astNode is not an object', () => {
+    it("doesn't call the visitor function", () => {
+      const visitorFunction = jest.fn();
+      const visitor = {
+        itemType: visitorFunction,
+      };
+
+      const astNode = 'astNode';
+
+      visit(astNode, visitor);
+
+      expect(visitorFunction).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('when the astNode is an object', () => {
+    describe("when the astNode has a string type that doesn't exist in the visitor object", () => {
+      it("doesn't call the visitor function", () => {
+        const visitorFunction = jest.fn();
+        const visitor = {
+          itemType: visitorFunction,
+        };
+
+        const astNode = {type: 'itemTypeNotInVisitor'};
+
+        visit(astNode, visitor);
+
+        expect(visitorFunction).not.toHaveBeenCalled();
+      });
+    });
+
+    describe('when the astNode has a string type that exists in the visitor object', () => {
+      it("doesn't call the visitor function", () => {
+        const visitorFunction = jest.fn();
+        const visitor = {
+          itemType: visitorFunction,
+        };
+
+        const astNode = {type: 'itemType'};
+
+        visit(astNode, visitor);
+
+        expect(visitorFunction).toHaveBeenCalledTimes(1);
+      });
+    });
+
+    describe("when the astNode doesn't have a string type", () => {
+      it('iterates on every values of the astNode', () => {
+        const visitorFunction = jest.fn();
+        const visitor = {
+          itemType1: visitorFunction,
+          itemType2: visitorFunction,
+        };
+
+        const astNode = {
+          firstChildNode: {type: 'itemType1'},
+          secondChildNode: {type: 'itemType2'},
+          thirdChildNode: {type: 'itemType3'},
+        };
+
+        visit(astNode, visitor);
+
+        expect(visitorFunction).toHaveBeenCalledTimes(2);
+      });
+    });
+  });
+
+  describe('when the astNode is an array', () => {
+    it('iterates on every values of the astNode', () => {
+      const visitorFunction = jest.fn();
+      const visitor = {
+        itemType1: visitorFunction,
+        itemType2: visitorFunction,
+      };
+
+      const astNode = [
+        {type: 'itemType1'},
+        {type: 'itemType2'},
+        {type: 'itemType3'},
+      ];
+
+      visit(astNode, visitor);
+
+      expect(visitorFunction).toHaveBeenCalledTimes(2);
+    });
+  });
+});

packages/react-native-codegen/src/parsers/flow/index.js

@@ -17,12 +17,13 @@ const fs = require('fs');
 const {
   extractNativeModuleName,
   createParserErrorCapturer,
+  visit,
 } = require('../utils.js');
 const {buildComponentSchema} = require('./components');
 const {wrapComponentSchema} = require('./components/schema');
 const {buildModuleSchema} = require('./modules');
 const {wrapModuleSchema} = require('../parsers-commons');
-const {visit, isModuleRegistryCall} = require('./utils');
+const {isModuleRegistryCall} = require('./utils');
 const invariant = require('invariant');
 
 function getConfigType(

packages/react-native-codegen/src/parsers/flow/modules/index.js

@@ -27,10 +27,10 @@ import type {NativeModuleTypeAnnotation} from '../../../CodegenSchema.js';
 const {nullGuard} = require('../../parsers-utils');
 
 const {throwIfMoreThanOneModuleRegistryCalls} = require('../../error-utils');
+const {visit} = require('../../utils');
 const {
   resolveTypeAnnotation,
   getTypes,
-  visit,
   isModuleRegistryCall,
 } = require('../utils.js');
 const {

packages/react-native-codegen/src/parsers/flow/utils.js

@@ -116,35 +116,6 @@ function getValueFromTypes(value: ASTNode, types: TypeDeclarationMap): ASTNode {
   return value;
 }
 
-// TODO(T71778680): Flow-type ASTNodes.
-function visit(
-  astNode: $FlowFixMe,
-  visitor: {
-    [type: string]: (node: $FlowFixMe) => void,
-  },
-) {
-  const queue = [astNode];
-  while (queue.length !== 0) {
-    let item = queue.shift();
-
-    if (!(typeof item === 'object' && item != null)) {
-      continue;
-    }
-
-    if (
-      typeof item.type === 'string' &&
-      typeof visitor[item.type] === 'function'
-    ) {
-      // Don't visit any children
-      visitor[item.type](item);
-    } else if (Array.isArray(item)) {
-      queue.push(...item);
-    } else {
-      queue.push(...Object.values(item));
-    }
-  }
-}
-
 // TODO(T71778680): Flow-type ASTNodes.
 function isModuleRegistryCall(node: $FlowFixMe): boolean {
   if (node.type !== 'CallExpression') {
@@ -188,6 +159,5 @@ module.exports = {
   getValueFromTypes,
   resolveTypeAnnotation,
   getTypes,
-  visit,
   isModuleRegistryCall,
 };

packages/react-native-codegen/src/parsers/typescript/index.js

@@ -16,13 +16,14 @@ const fs = require('fs');
 const {
   extractNativeModuleName,
   createParserErrorCapturer,
+  visit,
 } = require('../utils.js');
 const {buildComponentSchema} = require('./components');
 const {wrapComponentSchema} = require('./components/schema');
 const {buildModuleSchema} = require('./modules');
 const {wrapModuleSchema} = require('../parsers-commons');
 
-const {visit, isModuleRegistryCall} = require('./utils');
+const {isModuleRegistryCall} = require('./utils');
 const invariant = require('invariant');
 
 function getConfigType(

packages/react-native-codegen/src/parsers/typescript/modules/index.js

@@ -27,10 +27,10 @@ import type {NativeModuleTypeAnnotation} from '../../../CodegenSchema.js';
 const {nullGuard} = require('../../parsers-utils');
 
 const {throwIfMoreThanOneModuleRegistryCalls} = require('../../error-utils');
+const {visit} = require('../../utils');
 const {
   resolveTypeAnnotation,
   getTypes,
-  visit,
   isModuleRegistryCall,
 } = require('../utils.js');
 const {

packages/react-native-codegen/src/parsers/typescript/utils.js

@@ -109,35 +109,6 @@ function resolveTypeAnnotation(
   };
 }
 
-// TODO(T108222691): Use flow-types for @babel/parser
-function visit(
-  astNode: $FlowFixMe,
-  visitor: {
-    [type: string]: (node: $FlowFixMe) => void,
-  },
-) {
-  const queue = [astNode];
-  while (queue.length !== 0) {
-    let item = queue.shift();
-
-    if (!(typeof item === 'object' && item != null)) {
-      continue;
-    }
-
-    if (
-      typeof item.type === 'string' &&
-      typeof visitor[item.type] === 'function'
-    ) {
-      // Don't visit any children
-      visitor[item.type](item);
-    } else if (Array.isArray(item)) {
-      queue.push(...item);
-    } else {
-      queue.push(...Object.values(item));
-    }
-  }
-}
-
 // TODO(T108222691): Use flow-types for @babel/parser
 function isModuleRegistryCall(node: $FlowFixMe): boolean {
   if (node.type !== 'CallExpression') {
@@ -180,6 +151,5 @@ function isModuleRegistryCall(node: $FlowFixMe): boolean {
 module.exports = {
   resolveTypeAnnotation,
   getTypes,
-  visit,
   isModuleRegistryCall,
 };

packages/react-native-codegen/src/parsers/utils.js

@@ -54,7 +54,37 @@ function createParserErrorCapturer(): [
   return [errors, guard];
 }
 
+// TODO(T108222691): Use flow-types for @babel/parser
+function visit(
+  astNode: $FlowFixMe,
+  visitor: {
+    [type: string]: (node: $FlowFixMe) => void,
+  },
+) {
+  const queue = [astNode];
+  while (queue.length !== 0) {
+    let item = queue.shift();
+
+    if (!(typeof item === 'object' && item != null)) {
+      continue;
+    }
+
+    if (
+      typeof item.type === 'string' &&
+      typeof visitor[item.type] === 'function'
+    ) {
+      // Don't visit any children
+      visitor[item.type](item);
+    } else if (Array.isArray(item)) {
+      queue.push(...item);
+    } else {
+      queue.push(...Object.values(item));
+    }
+  }
+}
+
 module.exports = {
   extractNativeModuleName,
   createParserErrorCapturer,
+  visit,
 };