| name | tsz-emit |
| description | Write better tsz JavaScript and declaration emit code. Use when changing crates/tsz-emitter, emit transforms, DTS output, source maps, helper scheduling, temp/hoist planning, target/module output, or emit parity tests. |
TSZ Emit
Use for JS/DTS emit, transforms, helpers, temp/hoist planning, target/module
output, source maps, and emit parity tests.
Start
- Read
AGENTS.md and docs/plan/ROADMAP.md for durable emit/DTS work.
- Inspect overlapping emit PRs/issues.
- Name the failure family: target gate, module/export schedule, helper, temp/
hoist, region transform, printer layout, DTS nameability/portability,
source maps, or parser recovery.
- State:
When <syntax/output context>, tsc emits X; tsz emits X through <owner>.
Architecture
- Emit is
OUTPUT: no checker/solver semantic validation in emitter code.
- Prefer planned facts before writing text: target/module facts, helper needs,
temp reservations, hoists, prologues, exports, resource/disposable regions.
- Keep direct-to-target emit; do not introduce an
ESNext -> ... -> ES5
pipeline.
- No semantic output surgery with
replace, replacen, or replace_range.
Data cleanup is fine for escaping, source-map paths, numeric separators, and
path normalization.
- DTS should use declaration summaries/structured emission, not late string
rewrites.
Hot Checks
- Use writer/list/token/source-map helpers; add delimiter helpers when they
prevent real mistakes.
- Target/module policy belongs in target/module facts or emit-plan-like owners,
not random printer branches.
- Every function-like body needs temp scope and hoist strategy. Bypasses of
emit_block must still handle function-body flags and insertion points.
- Check adjacent shapes: arrows, declarations, expressions, methods, accessors,
constructors, async/generator wrappers, static blocks, namespaces/modules,
parameter prologues, ES2015+ and relevant legacy targets.
Verification
No full emit/conformance/fourslash locally.
scripts/emit/run.sh --filter=<family> --js-only --verbose --json-out=/tmp/<name>.json
scripts/emit/run.sh --filter=<family> --dts-only --verbose --json-out=/tmp/<name>.json
cargo nextest run -p tsz-emitter <test-or-family>
PR body: Goal: hold, failure family, structural rule, owner layer, why no
semantic validation/output surgery, targeted verification, unsupported shapes.
