Typescript Declare Module

Two that I know of are a Ambient Interface Declaration and a Ambient Class Declaration. TypeScript introduction part III - generics & stuff. The benefits of using AMD are outlined on the github page linked above as well as in the Dojo tutorial on defining modules. json to get configuration options for generating JavaScript code from TypeScript sourcecode. If you haven't already, be sure to check out part I and II for getting started with TS and knowing what's going on in this tutorial. The syntax for the module. typescript-modules-helper. Javascript works the same way when working with CommonJS or ES modules. Ambient Declarations. A simple example would be:. TypeScript compiles to clean, readable, standards-based JavaScript. Given a hello. Take the following code;. Static Type Checking Static type checkers like Flow and TypeScript identify certain types of problems before you even run your code. The TypeScript code we write is in the global scope by default. TypeScript Code is converted into Plain JavaScript Code:: TypeScript code is not understandable by the browsers. Modules are executed within their own scope, not in the global scope; this means that variables, functions, classes, etc. TypeScript. Learn how to create your own type definition files and how to contribute to the TypeScript community at DefinitelyTyped # Helping your community is AWESOME # It is Saturday evening and it’s raining a lot in Ireland. If you are using @babel/preset-env , you can use the modules option ; otherwise you can load the specific plugin. That’s why Vue ships with official type declarations for TypeScript - not only in Vue core, but also for vue-router and vuex as well. In this session, we sort out the mess and talk about the differences between internal and external modules, writing client and server code, how the TypeScript modules map to JavaScript modules in different versions of JavaScript, and about integration with build tools like Gulp. TypeScript ambient module: As we discussed in earlier tutorials TypeScript provides the facility to safely and easily use existing JavaScript libraries like jquery, angularjs, nodejs etc. Typescript react - Could not find a declaration file for module ''react-materialize'. How to declare a function type variable in Typescript? Posted on 2016-08-11 There are many types in typescript, but since we love callback functions in javascript, how do we declare them in typescript?. The sweet combination for me is the beautiful TypeScript, plus the phenomenal Knockout, plus whatever node modules I want to call (along with TypeScript declarations from DefinitelyTyped). I talk about what declaration files are, how to search and install them. Modules help with code organisation and reduce global scope pollution. declare module L { // all our code will end up here } If you wonder, why declare, well TypeScript complains otherwise: A declare modifier is required for a top level declaration in a. By using declaration files (also called. If you just want to indicate the intent of an import (so you don't want to declare a global) but don't wish to bother with any explicit definitions, you can import an ambient module. TypeScript compiles to clean, readable, standards-based JavaScript. After that, include a script for linting into package. I also show how you can publish. The name of the executable is typedoc. See Modules for more information. Don't confuse it with the dynamic import() syntax. Top-down documentation works well for large projects that already have some kind of documentation. IntelliSense for JavaScript libraries and frameworks is powered by TypeScript type declaration (typings) files. You will sometimes have to change your code to fit the type using the top-down approach as well. TypeScript to ES2015 (ES6) to ES5 via Babel 6 March 18, 2016 January 28, 2018 matthewrwilton babel , gulp , typescript Note: ES2015 is the official name for ES6, but to provide a better distinction between it and ES5 (the previous version) I’ll refer to it as ES6 from here on. The module system is an interesting feature of TypeScript, the statically typed superset of JavaScript. It all depends on how the module that you are importing is structured. If boxen were TypeScript module, it would have the types built-in, that's one place to get them. Finally, we will register the TypeScript controller in our Angular module. ts or a declaration only contributes to the global name declaration space if there is no root level import or export. This helps make it clear to the author that there will be no code emitted by TypeScript. typescript-modules-helper. A static type system can help prevent many potential runtime errors, especially as applications grow. CommonJS is the Node module system - Typescript is typically configured to use this system. TypeScript provides a system (this mechanism is also available in Visual Studio for JavaScript) by which we can make modules available inside other modules and even throughout the program. Hey Guys, Just found an issue with JET 7. TypeScript has the ability to take advantage of a pair of JavaScript modularization standards – CommonJS and Asynchronous Module Definition (AMD). ts you need to refer it as: /// The ambient type declaration in typescript will have a reference to the third party library and will re-declare the functions required with its own type. In typescript there are two types of modules:. Support for Modules - TypeScript uses Module system. There are many type definition files have been already uploaded to DefinitelyTyped. In this course, Jess Chadwick teaches you how to leverage the full power of the TypeScript language in your JavaScript applications, starting by revisiting some JavaScript fundamentals. 😉 In this article, we're going to finally explore generics, some complex types and declaration files. This file contains the ambient declarations for various common JavaScript constructs present in JavaScript runtimes and the DOM. Writing a Video. Starting with ECMAScript 2015, JavaScript has a concept of modules. In this video I'm talking about TypeScript Modules 01:25 Exporting from a module 02:49 Importing into a module 04:12 Default export 07:01 Renaming imports 08:22 Importing into a namespace variable. Inside the module, we can now define the interface, with the additional property drawControl, make sure the property is optional. js libraries. Use TypeScript and its Features like Types, ES6 Support, Classes, Modules, Interfaces and much more in any of their Projects Understand what TypeScript really is about and how it works Why TypeScript offers a real advantage over vanilla JavaScript. When this checkbox is cleared, import statements are generated in compliance with the TypeScript classic module resolution strategy. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. Writing a Node. Unfortunately, that's just how module resolution works in Node. Take the following code;. ts extension. Some of these i hope will end up inside the quasar module as types, but until now this is a nice start. TypeScript - Modules - A module is designed with the idea to organize code written in TypeScript. translate the code into JavaScript. TypeScript 2. VAR - When executed in variable declaration (where variable name should stand), suggests name for the variable. TypeScript Support. More commonly, TypeScript modules say export myFunction in which case myFunction will be one of the properties on the exported object. It adds a variety of helpful syntax and tools onto an already mature language, bringing the power and productivity of static typing and object-oriented development to core JavaScript. There is a few ways to create ambient declarations. Luckily, options exist to add stronger types to JavaScript. /bar'" statements for you. For our own modules that we have not converted into Typescript yet, we need to write type declaration files ourselves as a stop-gap arrangement till the time we convert that module into Typescript; Installing type declaration files for external modules Type declaration files for most NPM packages are already made available by the community. Copy this file to your project and in your TypeScript file add a reference to it as demonstrated below: /// You can optionally include the latest jQuery TypeScript definition file as well. Create a @types folder and put a jsx. Javascript works the same way when working with CommonJS or ES modules. TypeScript, developed by Microsoft, is a superset of JavaScript. Ambient Declarations. These capabilities allow for projects to be organized in a manner similar to what a “mature,” traditional server-side OO language provides. By default, TypeScript can’t infer types, so you need to define these files to help the type checker, but also to get better autocompletion in your code editor. The name of the executable is typedoc. You can easily install the crypto-js library in node by using the command (on Mac): > npm install crypto-js After that you need to download its. For example, by default the TypeScript compiler will print an error. Regarding triple-slash directives, I think they're safe to use. We no how an external module type. The process to adding these declaration files to your project has changed so information you find. It’s the same because TypeScript is a superset of JavaScript. TypeScript lets you write JavaScript "the way you really want to. json with validation rules for TypeScript into your project. A bundler (either tsc, Webpack, or Parcel) combines CommonJS modules into one file for use in a. Module declaration. The module name is resolved the same way as module specifiers in import/export. declare module "*. // types/mdx. atom-typescript supports all the same options the TypeScript compiler does as it's using it behind the scenes to do all of the heavy lifting. NET and looks like this: module MyInternalModule { export class MyClass { } } Internal modules are as they are labeled, internal, this means that it is different from what you are used to in NodeJS. We can declare a module by using the export keyword. ts を次のように変更した場合( export に注目):. The current solution is to use react-docgen-typescript-loader to preprocess the TypeScript files to give the Info addon what it needs. TypeScript is a language for application-scale JavaScript. A module is just like a namespace in C# and a logical division of objects. svg files: custom. Typescript react - Could not find a declaration file for module ''react-materialize'. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. If you haven't already, be sure to check out part I and II for getting started with TS and knowing what's going on in this tutorial. Currently, we are using TypeScript version 2. /bar'" statements for you. js extensions to the names of ES6 modules in import statements. Official Declaration in NPM Packages A static type system can help prevent many potential runtime errors, especially as applications grow. See the excellent advice on setting Cypress using TypeScript in the TypeScript Deep Dive e-book by Basarat Syed. translate the code into JavaScript. TypeScript offers type annotations which provide optional, static type checking at compile time. TypeScript expects the tsconfig. NET world, is very easy to use, and meshes well with. For instance,. You just need to know how to translate documentation into Typescript types; the Declaration section of the Typescript handbook is a good starting point for this. Which you prefer is a matter of preference, they each have their own approach on how to add the magic of. 9, released in 2013, added support for generics Typescript 1. A static type system can help prevent many potential runtime errors, especially as applications grow. Both features in TypeScript support encapsulation of classes, interfaces, functions and variables into containers. Currently, we have two ways to define a global variable, the first one is use @types define it, and the second one is use declare global in a module. This is drives typescript compiler nuts. Creating an HTTP server with ExpressJS and TypeScript, thus creating a web interface that can help us deliver our compiled file and log our output to the Logger Console. The workaround is to define the function in the module and use it in the class. In this TypeScript tutorial I will show you how to create a Ambient Declarations file for a popular JavaScript library. Angular packages include them already. We put the required types such as classes and interfaces in a module. " TypeScript compiles to plain JavaScript, so it works in any browser, any host, and any OS. Ambient declaration files are saved with. Javascript works the same way when working with CommonJS or ES modules. Once I moved the interfaces into the module boundaries everything got fixed. In this section, we will learn about Modules in TypeScript. The very handy Storybook Info addon autogenerates prop tables documentation for each component, however it doesn’t work with Typescript types. To use the File System module in TypeScript, we first need to import it. If jQuery didn't have type declarations (), you could put. When you target version 2. It adds a variety of helpful syntax and tools onto an already mature language, bringing the power and productivity of static typing and object-oriented development to core JavaScript. Some of these i hope will end up inside the quasar module as types, but until now this is a nice start. computed() in TypeScript On my second day of figuring out how to use knockout. This can be achieved using reference comments on top of the module in which we want to reference other module. JavaScript! We all love it. In fact, atom-typescript will use the exact version of TypeScript you have installed in your node_modules directory. declare module "*. A while back we talked about how TypeScript 2. Adds "import Foo from '. Depending on the way you code and the TypeScript version that you use, there are 2 ways to add a new property to the window: 1. Inaccessible module error in TypeScript declaration file. CommonJS is the Node module system - Typescript is typically configured to use this system. By default, TypeScript does not use any sort of Asynchronous Module Defition (AMD) pattern. Create a @types folder and put a jsx. Just as there is a one-to-one correspondence between JS files and modules, TypeScript has a one-to-one correspondence between module source files and their emitted JS files. ts file in your types directory and include it inside your tsconfig. A module is a container of objects. A TypeScript interface declaration, inline interface type, or function type. As we mentioned in why TypeScript: A major design goal of TypeScript was to make it possible for you to safely and easily use existing JavaScript libraries in TypeScript. When using a bare path for the ‘extends’ field in tsconfig. When importing a dependency into a TypeScript code base, you might get this error. TypeScript, developed by Microsoft, is a superset of JavaScript. Top-down documentation works well for large projects that already have some kind of documentation. After importing a testcafe module, an IDE (e. After that, include a script for linting into package. END - The caret position after the template is applied. declare module "*. Creating an HTTP server with ExpressJS and TypeScript, thus creating a web interface that can help us deliver our compiled file and log our output to the Logger Console. We can declare a module by using the export keyword. Given a hello. TypeScript does this by means of declaration. I also show how you can publish. Using TypeScript with the TSDocgen addon. We control the output format and module syntax so that downstream rules can rely on them. ts then each root level definition must have the declare keyword prefixed to it. I have created an overview of the different ways by which a module can be exported, together with their corresponding import syntax. Ambient declarations is a promise. The author needs to ensure that the declared item will exist at runtime. There is a few ways to create ambient declarations. Shortcut : ctrl+alt+l or cmd+alt+l. The TypeScript declare keyword is used to declare variables that may not have originated from a TypeScript file. You will sometimes have to change your code to fit the type using the top-down approach as well. The typings file I used as a template had private interfaces at the end of the file. TypeScript has the ability to take advantage of a pair of JavaScript modularization standards – CommonJS and Asynchronous Module Definition (AMD). TypeScript distinguishes between modules and namespaces. ts To use the file filename. ctor (Imported TypeScript Snippets). 0 and typescript that means you cannot compile the application. Friday 17th August 2018. declare module "name-of-untyped-module"; declare module "another-untyped-module"; This is the simplest way to tell the compiler that the modules exist and you don't want them to have any type restrictions. Configuring TypeScript. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. In this section, we will learn about Modules in TypeScript. Unfortunately, that's just how module resolution works in Node. Typescript interprets *. In our types directory we have one top level index. Using the declare keyword with modules and classes means that your TypeScript code can extend the code in the JavaScript file. Both features in TypeScript support encapsulation of classes, interfaces, functions and variables into containers. When this checkbox is selected, PyCharm automatically adds the. Let us make sure we know the TypeScript terminology; internal modules are called namespaces and external modules are just modules just like ES6. typescript-modules-helper. TypeScript source code and project is available on github. svg and defining the module's content as any. ECMAScript 2015(ES6) module system treats every file as a module. Starting with ECMAScript 2015, JavaScript has a concept of modules. CommonJS is the Node module system - Typescript is typically configured to use this system. Writing a Node. After that, include a script for linting into package. When using Node module resolution, TypeScript will now first look at a new field called typesVersions, which will check whether the current version of TypeScript is running or not, and redirect. One effect of this is that it’s not possible to concatenate multiple module source files depending on the module system you target. After importing a testcafe module, an IDE (e. Global Type Declaration A. atom-typescript supports all the same options the TypeScript compiler does as it's using it behind the scenes to do all of the heavy lifting. Since it created with CommonJS style of exports, we can require the whole module with import * as fs. This is because it provides great out-of-the-box support for TypeScript. TypeScript distinguishes between modules and namespaces. We want to transform TypeScript modules with ts-jest. As of version 3. Declaration files has extension ". The TypeScript compiler supports various JavaScript module systems such as ES2015, CommonJS, or AMD. Extend Express Request and Response : Typescript Declaration Merging February 12, 2019 When we use TypeScript to Build a Node API with Express, you might need to add some additional properties to the Express request and response object. When using Node module resolution, TypeScript will now first look at a new field called typesVersions, which will check whether the current version of TypeScript is running or not, and redirect. END - The caret position after the template is applied. Gain insights into core and advanced TypeScript language features Integrate existing JavaScript libraries and third-party frameworks using declaration files Target popular JavaScript frameworks, such as Angular, React, and more Create test suites for your application with Jasmine and Selenium. Like the TypeScript compiler, TypeDoc comes with a binary that can be called from anywhere if you install TypeDoc as a global module. TypeScript, developed by Microsoft, is a superset of JavaScript. VARKIND - Displays the specified list of values. IntelliSense for JavaScript libraries and frameworks is powered by TypeScript type declaration (typings) files. TypeScript includes a special declaration file called lib. Unfortunately, that's just how module resolution works in Node. Comparing to JavaScript, One of my favorite TypeScript features is that we can create a TypeScript declaration file (. TypeScript - Modules - A module is designed with the idea to organize code written in TypeScript. But it shouldn't matter if your dependency is up four directories vs. TypeScript compiles to clean, readable, standards-based JavaScript. Or you copy-paste import sections between files that are at different levels in the project tree. Adding static methods to existing modules using Declaration Merging in TypeScript Introduction. A static type system can help prevent many potential runtime errors, especially as applications grow. In this TypeScript tutorial I will show you how to create a Ambient Declarations file for a popular JavaScript library. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript tutorial in Visual Studio Code. 7 (#10543, #10545) TypeScript 3. Why do I need it? A few months ago I ran into a problem while building an app with TypeScript and Firebase. Depending on the way you code and the TypeScript version that you use, there are 2 ways to add a new property to the window: 1. In this video I'm talking about TypeScript Modules 01:25 Exporting from a module 02:49 Importing into a module 04:12 Default export 07:01 Renaming imports 08:22 Importing into a namespace variable. Copy this file to your project and in your TypeScript file add a reference to it as demonstrated below: /// You can optionally include the latest jQuery TypeScript definition file as well. AmazingClass { }. The name of the executable is typedoc. json file, pointing to the Javascript module, and running npm publish. These capabilities allow for projects to be organized in a manner similar to what a “mature,” traditional server-side OO language provides. The process to adding these declaration files to your project has changed so information you find. TypeDoc accepts most of the command line arguments that the TypeScript compiler accepts. /bar'" statements for you. These declaration files provide intelligence when using library functions and variables. Modules provide the possibility to group related logic, encapsulate it, structure your code and prevent pollution of the global namespace. $ npm install typedoc --global $ typedoc Usage Shell. Each Kendo UI distribution includes a typescript directory which contains a. TypeScript - Module. In TypeScript, declaration files (. This requires a custom. ts を次のように変更した場合( export に注目):. Change your TypeScript config so your compiler options allow for extra types: {". In order to declare a class-based component, you need to create a class that extends vue (here it’s imported from the vue-property-decorator package rather than the vue module directly). Then the declarations in an augmentation are merged as if they were declared in the same file as the original. It features static typing, class, and interface. Like the TypeScript compiler, TypeDoc comes with a binary that can be called from anywhere if you install TypeDoc as a global module. Inside the module, we can now define the interface, with the additional property drawControl, make sure the property is optional. TypeScript has a special syntax for exporting and importing modules; however, the language can’t directly handle the wiring between files, so we need some third party libraries to facilitate the use of external modules. An ambient declaration introduces a variable into a TypeScript scope, but has zero impact on the emitted JavaScript program. In order to extend it, we have a declare a module using the same name and in that module, we will declare an interface with the same name as the class we are trying to extend. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. Declaration Spaces TypeScriptには、 変数 宣言空間と 型 宣言空間という2つの宣言空間があります。 これらの概念については以下で解説します。. It is based on React and can be integrated into any web app. When importing a dependency into a TypeScript code base, you might get this error. Adds "go to declaration" that works with modules declared elsewhere, and fallbacks to atom-typescript go to declaration, just ctrl/cmd click an indexed symbol. TypeScript compiles to clean, readable, standards-based JavaScript. The module system is an interesting feature of TypeScript, the statically typed superset of JavaScript. TypeScript has a special syntax for exporting and importing modules; however, the language can’t directly handle the wiring between files, so we need some third party libraries to facilitate the use of external modules. This helps make it clear to the author that there will be no code emitted by TypeScript. VAR - When executed in variable declaration (where variable name should stand), suggests name for the variable. // types/mdx. The sweet combination for me is the beautiful TypeScript, plus the phenomenal Knockout, plus whatever node modules I want to call (along with TypeScript declarations from DefinitelyTyped). TypeScript implements external modules that are closely aligned with those proposed for ECMAScript 6 and supports code generation targeting CommonJS and AMD module systems. 7 RC includes support for optional chaining, nullish coalescing operator, assertion functions, type-only field declarations and many more type-related features. Trade-offs of Modules. js and keeps cached bound ASTs for input files which saves time. Module declaration. The Javascript ecosystem benefited greatly from NPM by proliferating ideas of code-reuse and modular design. Typescript does not resolve modules through tsconfig. TypeScript ambient module: As we discussed in earlier tutorials TypeScript provides the facility to safely and easily use existing JavaScript libraries like jquery, angularjs, nodejs etc. In this session, we sort out the mess and talk about the differences between internal and external modules, writing client and server code, how the TypeScript modules map to JavaScript modules in different versions of JavaScript, and about integration with build tools like Gulp. TypeScript shares this concept. In this video I'm talking about TypeScript Modules 01:25 Exporting from a module 02:49 Importing into a module 04:12 Default export 07:01 Renaming imports 08:22 Importing into a namespace variable. Creating a new Javascript module and distributing it is as simple as creating a package. CommonJS is the Node module system - Typescript is typically configured to use this system. 9, released in 2013, added support for generics Typescript 1. Lately, I’ve started using AngularJS instead of Knockout. We put the required types such as classes and interfaces in a module. Modules provide the possibility to group related logic, encapsulate it, structure your code and prevent pollution of the global namespace. Adds "go to declaration" that works with modules declared elsewhere, and fallbacks to atom-typescript go to declaration, just ctrl/cmd click an indexed symbol. This process avoids re-parse and re-JIT of the >1MB typescript. Hi, SonarQuber Version: 6. I rewrite on of the files in ts and i want to specify that other files at this moment can contain any content. For developing Vue applications with TypeScript, we strongly recommend using Visual Studio Code, which provides great out-of-the-box support for TypeScript. Angular packages include them already. Declaring Modules in TypeScript. In our types directory we have one top level index. Then the declarations in an augmentation are merged as if they were declared in the same file as the original. ts file which signifies custom definitions for TypeScript in our project. Currently, we have two ways to define a global variable, the first one is use @types define it, and the second one is use declare global in a module. Hope this will be helpful for others, happy typescript hacking. There is a few ways to create ambient declarations. JavaScript! We all love it. json, TypeScript will dive into node_modules packages for us,” Rosenwasser wrote. By default, module path resolution for relative module IDs is the same in TypeScript as it is in AMD and CommonJS, where the module ID is resolved relative to the directory containing the referencing module. The module system is an interesting feature of TypeScript, the statically typed superset of JavaScript. Modules are executed within their own scope, not in the global scope; this means that variables, functions, classes, etc. For developing Vue applications with TypeScript, we strongly recommend using Visual Studio Code, which provides great out-of-the-box support for TypeScript. atom-typescript supports all the same options the TypeScript compiler does as it's using it behind the scenes to do all of the heavy lifting. Now your watch window is a sea of red. Friday 17th August 2018. typescript-modules-helper. As a result, I feel like you may also have less opportunities to learn more advanced JavaScript knowledge than programming in pure JavaScript. 0 was released at Build 2014 ; All numbers in Typescript are floating point values. A simple example would be:. More commonly, TypeScript modules say export myFunction in which case myFunction will be one of the properties on the exported object. Take a look at this video Basarat has recorded and the accompanying repo basarat/cypress-ts. json to be in the root of your project as shown in the sample structure. I have created an overview of the different ways by which a module can be exported, together with their corresponding import syntax. The debug port can be selected with the --nodeDebugPort parameter on Azure Functions Core Tools. declare module L { // all our code will end up here } If you wonder, why declare, well TypeScript complains otherwise: A declare modifier is required for a top level declaration in a. net javascript mvc4 typescript AngularJS and TypeScript. TypeScript compiler uses tsconfig. NET world, is very easy to use, and meshes well with. Extend Express Request and Response : Typescript Declaration Merging February 12, 2019 When we use TypeScript to Build a Node API with Express, you might need to add some additional properties to the Express request and response object. ts file in it. // types/mdx. Modules are broadly divided into −. How to use external module/library in TypeScript You need a type definition file(. written in one file are accessible in all the other files. These definition files for libraries and frameworks are added to the list of your project’s External libraries, thus enhancing code completion. TypeScript ambient module: As we discussed in earlier tutorials TypeScript provides the facility to safely and easily use existing JavaScript libraries like jquery, angularjs, nodejs etc. // types/mdx. Will format just the selection if you. Even with TypeScript in the mix, ts-jest makes testing React applications easy. This is drives typescript compiler nuts. After importing a testcafe module, an IDE (e. The TypeScript declare keyword is used to declare variables that may not have originated from a TypeScript file. TypeScript modules are written in one of two modes: declaration mode or augmentation mode. ts, add the following line. I need to migrate step by step some large project from js to typeScript. Local JavaScript module type declaration. Modules are executed within their own scope, not in the global scope; this means that variables, functions, classes, etc. The understanding that I worked off of was that the import * as ModuleName from 'path/to/Module' format was for importing non-TypeScript/AMD modules (no default export) and import ModuleName from 'ModuleName' was for importing TypeScript modules. js plugin in Typescript. You can pass options to the TypeScript compiler by either by using the CLI, or a special file called tsconfig. 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: