Nathan Shively-Sanders 8d4fe5a0fb Fix unassignable properties by adding undefined with exactOptionalPropertyTypes (#45032)
* Simple first version

Doesn't cover or test any complicated variations.

* Lots of cases work

Destructuring does not. But

- skipping node_modules and lib.* does.
- call expressions does
- property access, including with private identifiers, does

* Support variable declarations, property assignments, destructuring

As long as it's not nested

* More cleanup

* skip all d.ts, not just node_modules/lib

* Offer a codefix for a lot more cases

* remove incorrect tuple check

* Use getSymbolId instead of converting to string

Co-authored-by: Andrew Branch <andrewbranch@users.noreply.github.com>

* add test + switch to tracking number symbol ids

* Address PR comments

* Exclude tuples from suggestion

* Better way to get error node

Plus add a check that errorNode is an argument to the call, not the
call's expression.

* fix semicolon lint

* fix another crash

* Simplify: add undefined to all optional propertie

whether or not somebody tried to assign undefined to them in the
erroneous assignment

* remove fix-all

Co-authored-by: Andrew Branch <andrewbranch@users.noreply.github.com>
2021-08-10 16:57:38 -07:00
2021-08-08 06:06:08 +00:00
2021-08-06 23:28:17 +00:00

TypeScript

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TypeScript is a language for application-scale JavaScript. TypeScript adds optional types to JavaScript that support tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the playground, and stay up to date via our blog and Twitter account.

Find others who are using TypeScript at our community page.

Installing

For the latest stable version:

npm install -g typescript

For our nightly builds:

npm install -g typescript@next

Contribute

There are many ways to contribute to TypeScript.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Documentation

Building

In order to build the TypeScript compiler, ensure that you have Git and Node.js installed.

Clone a copy of the repo:

git clone https://github.com/microsoft/TypeScript.git

Change to the TypeScript directory:

cd TypeScript

Install Gulp tools and dev dependencies:

npm install -g gulp
npm ci

Use one of the following to build and test:

gulp local             # Build the compiler into built/local.
gulp clean             # Delete the built compiler.
gulp LKG               # Replace the last known good with the built one.
                       # Bootstrapping step to be executed when the built compiler reaches a stable state.
gulp tests             # Build the test infrastructure using the built compiler.
gulp runtests          # Run tests using the built compiler and test infrastructure.
                       # You can override the specific suite runner used or specify a test for this command.
                       # Use --tests=<testPath> for a specific test and/or --runner=<runnerName> for a specific suite.
                       # Valid runners include conformance, compiler, fourslash, project, user, and docker
                       # The user and docker runners are extended test suite runners - the user runner
                       # works on disk in the tests/cases/user directory, while the docker runner works in containers.
                       # You'll need to have the docker executable in your system path for the docker runner to work.
gulp runtests-parallel # Like runtests, but split across multiple threads. Uses a number of threads equal to the system
                       # core count by default. Use --workers=<number> to adjust this.
gulp baseline-accept   # This replaces the baseline test results with the results obtained from gulp runtests.
gulp lint              # Runs eslint on the TypeScript source.
gulp help              # List the above commands.

Usage

node built/local/tsc.js hello.ts

Roadmap

For details on our planned features and future direction please refer to our roadmap.

Description
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
Readme 4.9 GiB
2025-07-30 13:28:01 -05:00
Languages
TypeScript 97.9%
jsonc 1.9%
JavaScript 0.2%