Clutz - Closure to TypeScript Declarations (.d.ts) generator.

This project uses the Closure Compiler to parse Closure-style JSDoc type annotations from ES5/ES2015 code, and generates a suitable TypeScript type definition file (.d.ts) for the exported API.

The intent is to allow TypeScript code to import libraries written with Closure-style type declarations. Having the clutz generated declarations allows type-checking in the TypeScript compiler and IDE tooling (for highlighting errors and type-sensitive auto-complete) as if the imported code was written in TypeScript.

Example usage

We don't offer a binary distribution, so first you need to build:

$ npm install 
$ gradle build installDist
...
BUILD SUCCESSFUL

You can use Clutz as a library from a Java based build, or execute the wrapper script produced by Gradle. Here is a sample execution:

$ PATH=$PATH:./build/install/clutz/bin
$ clutz path/to/my/source1.js path/to/my/source2.js ...
        --externs path/to/closure-compiler/externs/es3.js path/to/closure-compiler/externs/es5.js ...
        -o out.d.ts \

This creates TypeScript type definitions in out.d.ts for all the closure types discovered in the inputs. Symbols which were declared with goog.provide('x') may be imported in TypeScript as import x from 'goog:x';. For full explanation of what TypeScript types are produced for different Closure usages, see the .js and .d.ts files in src/test/com/google/javascript/clutz.

When compiling TypeScript code that depends on the closure code, include the src/resources/closure.lib.d.ts file along with out.d.ts.

Note that clutz requires that your code can be compiled with Closure Compiler. If you get errors, try reproducing them without clutz, by compiling your code with Closure alone. The arguments for invoking clutz are intentionally similar to the arguments for invoking the Closure compiler. You can find the additional compiler flags that clutz passes to Closure Compiler in src/main/java/com/google/javascript/clutz/Options.java. If the failure is reproducible this way, then you have a closure type error in your code (or a bug in Closure Compiler).

Supported Version of TypeScript

Clutz produces declaration files that are guaranteed to be accepted by a version of TypeScript 2.1.6. The current test suite runs against the version of typescript in npm-shrinkwrap.json, so that is always a good choice.