ADR 7: Pick Visualization Language

In ADR-3 we picked our visualization language JavaScript. The missing static typing of that language has become a minor issue:

• Some refactorings don’t have IDE support.
• It’s sometimes tricky to discern what methods and fields the passed function parameters sport.

Status

accepted

Decision

CodeCharta will use TypeScript. It’s developed since 2012 by a well-known company, has static types, tool support is increasing every day and many frontend frameworks support it. Plus CodeCharta already requires a build pipeline so no change there.

Consequences

• Existing JavaScript code needs to be migrated.
• Untyped libraries that don’t have types need to be supplied with them, custom written if necessary.
• Because TypeScript is a superset of JavaScript, it does introduce new syntax that is unfamiliar to JavaScript developers. This increases the learning curve for now and old developers.
• While Angular 2+ has first-class support for TypeScript, the same cannot be said for Angular 1.x. We’ll need to rely on the definitely typed community types.