gleam-lang/gleam

Typescript declarations are not emitted with existing build directory

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#4,520 opened on Apr 29, 2025

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 (3 comments) (0 reactions) (0 assignees)Rust (960 forks)batch import
good first issuehelp wanted

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Description

Given a gleam application with target = "javascript" will build the application just fine. However when I enable typescript_declarations = true in the gleam.toml config and build the project again, the .d.ts are not emitted until I rm -rf the build directory that was emitted without the declarations turned on.

gleam v1.10.0 runtime: javascript

Contributor guide

Research direction
Investigate the build directory caching behavior in the Gleam compiler. Trace the code path for generating TypeScript declarations when the build directory already exists. Determine why the declarations are not regenerated on subsequent builds when the config changes.
Tech stack
rust
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Rust
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40