Typescript Tooling

[samreid]

From the TypeScript investigation in phetsims/tasks#987, we developed some basic tooling for building TypeScript. For a full migration #1046, we will need:

Tooling Support

• Run type checker as a precommit hook
• Run type checker on CT. By default, output from tsc fails a build, so this will appear on CT.
• How do you know when the code finished compiling, so you can run it in the browser? We don't want to launch stale code. How do we normally do that with compiled languages? Maybe trigger the browser to reload on changes? I set up a keystroke in WebStorm to build all (based on Set up modular tsconfig projects #1055) and it works well.
• Make sure we aren't missing something that may cause problems for phet-io.
• Get more repos working as "composite": true, right now we have to put many repos together since they cross-reference, see Improve modularity of common code repos #1052
• Autogenerate project references from phetLibs
• get tsc --build --watch working for all repos. Should we make a macro tsconfig that references all sims as projects? Done in Set up modular tsconfig projects #1055
• Why does WebStorm create *.js files adjacent to *.ts files? A broken or missing tsconfig causes the default behavior of outputting js adjacent to ts.
• Test existing tooling on Windows. Incremental build times seem comparable to mac, no problem with --watch
• Add a grunt tsc-build step after pull on CT/phettest, for runnable repos. What if we pull sun or another common code repo--then run chipper build? Or should sun refer to chipper build file? Now that Set up modular tsconfig projects #1055 is complete, we could do tsc -b in all/. Tracked in CT needs a grunt tsc -b all step when pulling #1072 and phettest should run output-js #1073

Coverage

• Unit tests
• What if studio wants to import a typescript file?
• Would it work with PhET-iO? Will our wrappers remain in JS?
• Scouting out how it will work for node/preloads, even if we reserve that migration for a future quarter. See Migrate chipper build tools to TypeScript #1054
• How will we model the types of merge? Moved to How will we model the types of merge? phet-core#91

Extensions, Improvements and Next Steps

• Better support for importing *.ts file from *.js file, see How to import *.ts file from *.js file? #1045
• How could we revise/improve the string plugin? Import JSON files with typescript? see What is the optimal way to load strings using Typescript? #1053
• rename "js" directories to "src"

Many of these checkboxes should be addressed in side issues.

[samreid]

All issues complete or moved to side issues, closing.