Jest Mock Constructor Parameters

Raygun lets you detect and diagnose errors and performance issues in your codebase with ease It takes. Brief Explanation: I have create Ionic 4 app. In the how-to series today I will show how-to mock constructors using PowerMocks - Mocks on Steroids!. property when providing val. The below code is based on both Constructor Injection and Setter Injection. We are using jest. mock(path, moduleFactory) takes a module factory argument. js in the __mocks__ folder. For example:. You can always mock DateTime. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more. Now or any other static method directly inside Mock. export const myMap = (arr,fn) =>{ return arr. Getting to that mastery will seem incredibly onerous at first, but you won’t ever get there if you don’t go all in. After performing an action, you can make assertions about. js gRPC client for Zeebe. requireActual(moduleName). In order to mock a constructor function, the module factory must return a constructor function. You can use string literals with union types to mock a string based enum as we did in the CardinalDirection example above. The most obvious way to work with a mock is to use it as a parameter for methods and constructors. Learn more about fake time. 使用模块工厂参数的简单模拟(Simple mock using module factory parameter) 传递给jest. The goal is to create an up-to-date foundation for developer-side testing on the JVM. When testing code with Jest, it can sometimes be useful to fail a test arbitrarily. mock() 에 대한 호출은 호이스트(hosited) 되어 코드 상단으로 올라갑니다. It allows you to replace parts of your system under test with mock objects and make assertions about how they have been used. The next step after spending time developing your applications, and once you’re satisfied with your work, is to deploy them. If you’re going to write ’em, make ’em count. Provide the theory and downloadable code sample to demonstrate these. Testing constructor if null parameter is passed in. I have used the TDD approach to write the example, which also includes a mock object (Rhino Mock). history property. Unit testing your api calls can be cumbersome to some extent, for simplicity here i am using create-react-app and Enzyme and Jest (no redux or redux-thunk). Then created mock will have type of that class. If you have a constructor in your class then you must call the parent constructor from your constructor (TypeScript will point this out to you). If you want to provide a new implementation to a function you are spying on in this manner, try the following:. Configuring Jest. You should instead test your public interface. Moq is a very useful framework which easily mocks service calls and methods for your unit testing. After performing an action, you can make assertions about. To create a mock it is required to call static method Mockito. Please Help Me Get Better At Jest (Especially Mocks) submitted 5 hours ago * by P013370 I'm new to Node, and am working on a hobby project that will monitor a site's downtime. The rest of the class has been written to expose a getStudents method that returns the same mock data as before. This article helps you to understand Moq with respect to mocking a database (i. Mock which is generic. Setting up mock: We will be using file mock from jest to mock react-redux library. If you have not already done so, you might want to read the "getting-started. The basic problem is that the prototype is not transferred. Unit testing takes time to learn and even more time to master. As it turns out, this spy method does not work well with JavaScript constructors, in JsMockito, Jasmine, or many other testing frameworks. On top of just utilizing typescript to catch bugs, it's still important to make sure Typescript code is tested. This method will be executed when the component “mounts” (is added to the DOM) for. 使用模块工厂参数的简单模拟(Simple mock using module factory parameter) 传递给jest. additional query parameters that are sent when connecting a namespace (then found in socket. Arrow Functions Lovingly called the fat arrow (because -> is a thin arrow and => is a fat arrow) and also called a lambda function (because of other languages). 1] - Composite component. Returns the jest object for chaining. [1] These options are experimental. js Components with Jest 运用Jest测试Vue组件中的继承属性和自定义事件 There are different ways to test properties, events and custom events. Mock functions make it easy to test the links between code by erasing the actual implementation of a function, capturing calls to the function (and the parameters passed in those calls), capturing instances of constructor functions when instantiated with new, and allowing test-time configuration of return values. The rest of the class has been written to expose a getStudents method that returns the same mock data as before. This has been asked about long time ago. The following is a simple example to get started with: Extend your jest config (usually in package. Another commonly used feature is the fat arrow function ()=>something. mock API's second argument is a module factory instead of the expected exported module object. Let's implement those tests: Your test method names should provide a good idea. Can someone guide on how this is done in Jest? Thank you so much for your time!. When launched for the first time, Jest will generate snapshot files, and next times it will compare that the rendered element is still the same. Mocking passport githubStrategy for functional testing. js (a mocking and. This article helps you to understand Moq with respect to mocking a database (i. A module factory is a function that will return the mock. [2] These options are only allowed in tsconfig. Jest fully supports ES6 classes and provides various ways to mock them: Automatic mock: lets you spy on calls to constructor and all methods, but always returns undefined. Stay ahead with the world's most comprehensive technology and business learning platform. 下次介绍第三、四种方法 - 使用模块工厂参数调用jest. 1 The table below lists third party software that is incorporated into Confluent Platform 5. The string representation of the date which is passed to the new Date() constructor. The idea will be to use jest. html" sections, so that you have a good grounding of the basics. Yes! This functional approach is so simple yet so powerful and magicless. Summarize some key points of the "Should-you-even-test private methods debate"? Make the case that it is still useful to at least know how to test private and protected methods - regardless of which side of the debate you're on. now is used in application code. Google Guice is the framework to automate the dependency injection in applications. I have used the TDD approach to write the example, which also includes a mock object (Rhino Mock). > injection of dependencies should be done via an explicit method/constructor parameter. It also presents more idiomatic Jest patterns that could be used interc. Mock function capture the calls (and parameters) to our function, so later we can inspect the mock's state to check if our function was invoked as expected. Just use mockImplementation or spies, don't try to replicate the functionality and definitely don't test localStorage itself. The optional second parameter is a Boolean value that forces the class to be added or removed, regardless of whether or not it already existed. Typescript is a powerful way to build applications. This article will give you examples of common. There is nothing that can be passed as the module factory parameter (2nd parameter to jest. We'll be using the jasmine-marbles module in order to mock. If you are using jest then you can use mock timers to fast forward time. In these rare scenarios you can use this API to manually fill the slot in the module system's mock-module registry. The rest of the course covers an introduction to Unit Testing, Mocha (a JavaScript test runner), Grunt (a JavaScript task runner), Sinon. As the following code shows, this is extremely simple to do. The idea is to have Jest using the same structure but with the type swapped to use Jest's stub. options Optional. Extreme programming uses the creation of unit tests for test-driven development. In current post I will show how to improve test coverage by adding more scenarios. Mocked when creating the mock will exclude any code inside the constructor from execution and remove the dependency on the database. From the Jest docs: "Mock functions make it easy to test the links between code by erasing the actual implementation of a function, capturing calls to the function (and the parameters passed in those calls), capturing instances of constructor functions when instantiated with new, and allowing test-time configuration of return values. The SDKs provide a convenient way to create programmatic access to AWS KMS and other AWS services. js utilities. Mockito is library which allow to automatizate process of creations mock. The methods in jest object enable us to create mocks and helps us to control Jest?s overall behavior. forEach() works by using ECMAScript 5 Object. With that second parameter, we can just keep on using jOOQs DSL to construct the query. In this tutorial, we'll learn about how we can achieve this by using the PowerMock library - which is supported by JUnit and TestNG. If a file object is passed it should be opened with newline=’’, disabling universal newlines. Why would anyone want to define a zero argument constructor when a default parameterless constructor is created during compile time anyway? Are there any benefits to doing so? are there any cases where it is better to define a zero argument constructor within a class for the sole purpose of preventing the default from being created during compile time?. It allows you to replace parts of your system under test with mock objects and make assertions about how they have been used. mock() with the module factory parameter)和使用mockImplementation()或mockImplementationOnce()替换mock(Replacing the mock using mockImplementation() or mockImplementationOnce()) 实践项目地址. Returns the jest object for chaining. mock()(Calling jest. This is very easy:. Calling jest. In a normal setup, requiring a component file in a unit test will import React from react-native, which will start throwing errors immediately. Mock Functions · Jest. In conclusion, we are far from our past experience with Jest. No configuration, a very simple mock system, an interface designed for developers (for once, it's a compliment!), good performances… I strongly encourage you testing it! And, last but not least: Jest is not restricted to the React ecosystem. {constructor (props) {super(props Now Jest will use this file when you call jest. Let's implement those tests: Your test method names should provide a good idea. An object copy function. The following content comes from the second module of my Pluralsight course entitled: Front-End First: Testing and Prototyping JavaScript Apps. mock(path, moduleFactory) will take a module factory argument. XslCompiledTransform, when transforming, attempts to create an instance of the class, defined in the extension object, using the default parameter less constructor. This is a Node. When testing your rate limiting code works correctly it is helpful to have the ability to fast forward time. Jest Mock Window Constructor. When testing code with Jest, it can sometimes be useful to fail a test arbitrarily. We will be including mocha as a global module (we can use it without import statements), and chai as a dependency (we need to import it in our tests). Let's get started. Since they are private, consider them an implementation detail. The optional second parameter is a Boolean value that forces the class to be added or removed, regardless of whether or not it already existed. The ATB lets us test parts of our code as if it is being run in the context of a real Angular app. The purpose of this article is to explain how dependency injection helps unit testing in applications. Vue CLI has built-in options for unit testing with Jest or Mocha that works out of the box. Imagine, we have a class, in which a lot of logic is being executed inside a constructor. Your implementation of these methods can call on convenience methods built into the RESTDataSource class to perform HTTP requests, while making it easy to build up query parameters, parse JSON results, and handle errors. mock syntax. We already support spying on abstract classes by allowing parameterless constructor. Here is a very. The mock needs to be configurable to return a known sequence of responses, where each response is a promise that either resolves or rejects. in his free time, he enjoys playing acoustic guitar and spamming soundcloud with his. js app in an empty folder by running npm init. Once you know how to test for static HTML generated by your React component, then next step will be to test the dynamic code, the code that changes when you -- for instance -- press a button. Novelties in ECMAScript 6 (ECMAScript 2015, Harmony) - class and constructor syntax, static methods, inheritance, let and var, function lambdas (=>), template literals, destructuring assignment, default and rest parameters, spread operator, Promises. 1 Simulating function jest. The following is a simple example to get started with: Extend your jest config (usually in package. The next logical step in your build will be to build your solution or projects. mock() with the module factory parameter. Now I can mock an internal class from within a test project. However, it’s dangerous to negate. This procedure uses the VS Code Functions extension to create Azure Functions. mock(path,moduleFactory)的模块工厂函数可以是返回函数*的高阶函数(HOF)。 这将允许在模拟上调用new。 同样,这允许为测试注入不同的行为,但不提供监视调用的方法. Assemble a composite component Last chapter we built our first component; this chapter extends what we learned to build TaskList, a list of Tasks. ConstructorArgs public ConstructorArgs(Constructor constructor, Object initArgs) Parameters: constructor - Constructor to be called when creating the mock initArgs - Arguments passed to the constructor; Method Detail. mock vs Jest. Generates a mock based on the given metadata (Metadata for the mock in the schema returned by the getMetadata method of this module). mock() with the module factory parameter)jest. He was previously on the Angular core team at Google, and built the dependency injection, change detection, forms, and router modules. Using with Vue Router # Installing Vue Router in tests You should never install Vue Router on the Vue base constructor in tests. mock() with the module factory parameter. 0 The table below lists third party software that is incorporated into Confluent Platform 5. A module factory is a function that returns the mock. With Jest it's possible to assert of single or specific arguments/parameters of a mock function call with stubbing and spying on the date constructor using Jest. Edit: Apparently the method I used first doesn't work anymore, but there's a workaround to spy on Storage prototype. In order to mock any class methods in external assemblies defined in the extensions xml document, we just need to pass in pre-instantiated mock objects with methods whose signature. Mocking objects with Mockito with constructor argument and static classes that do nothing. So let's follow the "Constructors do nothing" rule by doing some refactoring. The string representation of the date which is passed to the new Date() constructor. com Like all functions, a constructor can have default arguments. componentDidMount is where the magic happens. mock()(Calling jest. Note in particular the call to jest. I’ve been always fan of using sinon. The problem is, i dont want it to show the menu by default and i have hide that menu using the below code: // Below code wll remove t. I'm trying to have a test setup function executed before each single test in my Jest test suite. Here I have used Microsoft Enterprise Library objects (to make it. The most obvious way to work with a mock is to use it as a parameter for methods and constructors. He was previously on the Angular core team at Google, and built the dependency injection, change detection, forms, and router modules. mock() with the module factory parameter)和使用mockImplementation()或mockImplementationOnce()替换mock(Replacing the mock using mockImplementation() or mockImplementationOnce()) 实践项目地址. Mock function. Calling jest. Supports any object that has a. The problem is that it creates uncertain expectations by asserting that the target either doesn’t have a property with the given key name, or that it does have a property with the given key name but its value isn’t equal to the given val. No need for an explaination. SetupStatic is useful if you are doing strict mocking using Behavior. 测试Vue组件中的继承属性、事件和自定义事件有很多种方法。. valueOf method that returns a value that can be passed to new Date(). Utilities for testing Vue components. Vue CLI has built-in options for unit testing with Jest or Mocha that works out of the box. I would use some kind of mocking technique to mock FunctionB when testing FunctionA. Jest Object. is it possible to mock class with parameter in constructor? public class testClass { public testClass(string s); } how do we mock this class? private Mock _testClass = new Mock(MockBehavior. Can check call parameters, call sequence, handle multiple implementations of a mock, and more. In this article I'm also explaining the main differences between Mock Objects and Stub objects, often confused when discussing about tests. Test case writing is an important part of software testing process and it is important to write test cases effectively in order to make your testing successful. It is written in TypeScript and transpiled to JavaScript in the dist directory. SetupStatic is useful if you are doing strict mocking using Behavior. fn function to mock our functions. Moq is a very useful framework which easily mocks service calls and methods for your unit testing. Unfortunately, if you want to omit the --flowVersion=0. But after importing it we replace the default export of the component mocked method. In this article, I will show you how to unit test routing from a specific AreaRegistration file. The window object represents an open window in a browser. Returns the jest object for chaining. Once you know how to test for static HTML generated by your React component, then next step will be to test the dynamic code, the code that changes when you -- for instance -- press a button. Calling jest. save() used to create a new Dynamoose object in Jest. writing unit test cases for your repository project). This is a potential source of confusion when using Mocha's asynchronous tests together with sinon. Can someone guide on how this is done in Jest? Thank you so much for your time!. Mocking: Jest provides easy ways to auto-mock or manually mock entities. fn() that defines this. If you have a constructor in your class then you must call the parent constructor from your constructor (TypeScript will point this out to you). There is nothing that can be passed as the module factory parameter (2nd parameter to jest. Jest Mock Class Property. js app in an empty folder by running npm init. It's that simple. The parameters of the callback function are: req, the request object. Requirement: Again, taking a fictitious example, lets say that ServiceA creates an instance of ServiceB and invokes a businessOperation on ServiceB's. Notice, on line 2, after I import the EventAggregator module I create a mock using the jest. Mock in Jest 2. The process is the I will have a node event password-rese. Google Guice is the framework to automate the dependency injection in applications. options Optional. jest tohavebeencalledwith multiple calls (3) To solve this you can use mock. Podobnie jak w poprzednim przykładzie jedyny element o nazwie value może być pominięty. You can use string literals with union types to mock a string based enum as we did in the CardinalDirection example above. If you'd like to use your package. Save it and mock-data. I'm trying to learn TDD approach. Variable names and imports that match the pattern will be ignored. The full list of mock methods we can call you can find here. Get Testing Superpowers with these Underused Jest Features Subscribe for free resources that turbocharge your Jest tests and a discount on the "Advanced Jest Handbook" Learn Jest. mock in your unit test. Can check call parameters, call sequence, handle multiple implementations of a mock, and more. To create a mock it is required to call static method Mockito. publish test requires some explaination. AngularJS code ———————. In this tutorial, we'll learn about how we can achieve this by using the PowerMock library - which is supported by JUnit and TestNG. fn() to create a Jest mock object which will serve as the export. You should instead test your public interface. Export the raw options:. In this instance, you can intercept requests to this resource and mock them using TestCafe. Vue CLI has built-in options for unit testing with Jest or Mocha that works out of the box. In this guide, we. Calling jest. Defining. When testing your rate limiting code works correctly it is helpful to have the ability to fast forward time. requireActual(moduleName). Mock Functions Mock functions are also known as "spies", because they let you spy on the behavior of a function that is called indirectly by some other code, rather than just testing the output. I want to test a method of a class. By calling provider. 종종 테스트를 작성할때 테스트가 실행되기전 설정 작업이 필요하면, 테스트가 실행되고 나서 설정 작업이 필요하다. ngOnInit jest funkcją, która wykonywana jest podczas inicjalizacji komponentu i która pobiera listę dostępnych tras z serwisu. In this short post we'll go over how to setup a simple unit test for an http GET request using that module, and in turn it should help demonstrate the capabilities of that new testing module. In this tutorial, we'll learn about how we can achieve this by using the PowerMock library - which is supported by JUnit and TestNG. Can someone guide on how this is done in Jest? Thank you so much for your time!. However, it’s dangerous to negate. mock()(Calling jest. mock() and mocks away the only external dependency this module had. With that second parameter, we can just keep on using jOOQs DSL to construct the query. Mock functions make it easy to test the links between code by erasing the actual implementation of a function, capturing calls to the function (and the parameters passed in those calls), capturing instances of constructor functions when instantiated with new, and allowing test-time configuration of return values. An object with properties prototype to base the custom element on, and extends, an existing tag to extend. Instead, develop good habits with TypeScript, dependency injection, and unit tests while doing something fun: Creating your own Discord bot from scratch!. You can create a mock function with jest. Arrow Functions Lovingly called the fat arrow (because -> is a thin arrow and => is a fat arrow) and also called a lambda function (because of other languages). If you want to mock a constructor function, the module factory has to return a constructor function. Don't Use HOCs Inside the render Method. Stay ahead with the world's most comprehensive technology and business learning platform. The canonical reference for building a production grade API with Spring. My solution was to create a function that returns a closure:. I did the following: setupFiles array and add jest-date-mock. We are now ready for a more advanced example. Test Smell: Mocking concrete classes One approach to Interaction Testing is to mock concrete classes rather than interfaces. async-i2c-bus. mock(path, moduleFactory) takes a module factory argument. Find support delegate contact options. In the how-to series today I will show how-to mock constructors using PowerMocks - Mocks on Steroids!. I have no troubles with a simple code where I do not need to mock or stub any external methods or dependencies, but where it comes to write tests for some code that based on database I'm getting feel a little bit confused. So let's follow the "Constructors do nothing" rule by doing some refactoring. Since we want to create a GraphQL interaction, we’re using Pact’s GraphQLInteraction class to describe this interaction. You want to make Scala functions, fields, and other code available at a package level, without requiring a class or object. Additionally, we should tell Jest to run the tests serially, rather than in a pool, so that we can be confident the tests are executed in the order we expect. And another from you accessing this. In this tutorial, we'll learn about how we can achieve this by using the PowerMock library - which is supported by JUnit and TestNG. When you want to test MyThing you use Jest, injectr, Squire, or one of the many helpers that load a mock instead of the real myService. A module factory is a function that returns the mock. Description. I need help mocking new TableName(params). There’s a much larger discussion to be had about how REST fits in the world of microservices, but - for this tutorial - let’s just look at building RESTful services. Mock functions allow you to test the links between code by erasing the actual implementation of a function, capturing calls to the function (and the parameters passed in those calls), capturing instances of constructor functions when instantiated with new, and allowing test-time configuration of return values. var layers = new Layers() I'm spying on it using. Jest has rapidly become a very popular, full-featured testing library. mock is a library for testing in Python. Any help would be greatly appreciated!. You can create a mock function with jest. json to replace the existing test command with the following command:. The idea is to have Jest using the same structure but with the type swapped to use Jest’s stub. The basic problem is that the prototype is not transferred. in his free time, he enjoys playing acoustic guitar and spamming soundcloud with his. [Storybook Doc 번역_v5. > injection of dependencies should be done via an explicit method/constructor parameter. The Date to be returned when no parameters are passed to new Date(). Welcome to PHPUnit! PHPUnit is a programmer-oriented testing framework for PHP. The rest of the course covers an introduction to Unit Testing, Mocha (a JavaScript test runner), Grunt (a JavaScript task runner), Sinon. The string representation of the date which is passed to the new Date() constructor. Google Guice is the framework to automate the dependency injection in applications. Get Testing Superpowers with these Underused Jest Features Subscribe for free resources that turbocharge your Jest tests and a discount on the "Advanced Jest Handbook" Learn Jest. js backend and I need to check out some values that come from a third party. The purpose of this article is to explain how dependency injection helps unit testing in applications. It also presents more idiomatic Jest patterns that could be used interc. Usage of fetch-mock with Jest is sufficiently different to previous libraries that it deserve some examples of its own:. The idea is to have Jest using the same structure but with the type swapped to use Jest's stub. In some frameworks many advanced unit test features are missing or must be hand-coded. Jest understands only JavaScript, therefore we have to map all non-js assets to something that Jest could understand (or at least to make sure that non JavaScript code like css and scss won’t get into our way). What about libs like lodash or jquery , things that are not modules that we created but is dependant on? We can create mocks for those at the highest level by creating a mocks directory. Now that we have typings installed, let’s get setup with the required type definitions. andReturn(mockObject) to expect a new construction of an object of type NewInstanceClass. Save it and mock-data. Arrow Functions Lovingly called the fat arrow (because -> is a thin arrow and => is a fat arrow) and also called a lambda function (because of other languages). Unit testing Vue js components with Jest - Kevin Peters - Medium. Unit testing takes time to learn and even more time to master. The goal is to create an up-to-date foundation for developer-side testing on the JVM. com/3fbtm/ltwab. Specific parameter asserts on a mock function call. This does not have to be a manual process, we can make use of React-Router. Espresso is a testing framework for writing UI tests in Android. Jest understands only JavaScript, therefore we have to map all non-js assets to something that Jest could understand (or at least to make sure that non JavaScript code like css and scss won’t get into our way). 测试Vue组件中的继承属性、事件和自定义事件有很多种方法。. 下次介绍第三、四种方法 - 使用模块工厂参数调用jest. simplify integration — unit testing may reduce uncertainty in the units themselves and can be used in a bottom-up testing style approach. First off let's separate the two classes by putting a interface between them. Both of these are optional. How to create a mockable class to connect to mongoDB. mock(path, moduleFactory) will take a module factory argument. Might be similar to Jest mocking function. I'd like to mock my ES6 class imports within my test files. Utilities for testing Vue components. We’re initializing state at the top using a class property. Configuring Jest Last update on October 14 2019 12:28:08 (UTC/GMT +8 hours) In this tutorial we will focus on configuring Jest. The window object represents an open window in a browser. Writing reusable components as ES6 classes. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: