claude@clouddev1
9efae59c3c
Each top-level tests/*.rs was its own crate → its own binary, each statically linking the bundled engine + every dep. 26 of them, so an edit to the lib relinked all 26. Moved the 25 standalone files into tests/it/ under one tests/it/main.rs (the pattern typing_surface already uses); cargo auto-detects it as the `it` target. End state: 2 integration-test binaries instead of 26. Result: target/debug/deps 1.5 GB → 629 MB (-58%). Build time barely moved (clean 22.9s→22.4s, lib-edit relink 13.3s→12.4s) — wall-clock is dominated by compiling, not linking, so this is a disk win, not a speed win (see docs/plans/20260602-test-consolidation.md). Tests unchanged at 2151/0/1; clippy clean; no fixups needed. typing_surface_matrix stays its own already-consolidated binary. Tradeoff: the 25 files now share one crate (a compile error fails the whole `it` binary; module-scoped namespaces, no clashes) — negligible for a solo project.
89 lines
3.5 KiB
Markdown
89 lines
3.5 KiB
Markdown
# Plan: consolidate integration tests into one binary
|
||
|
||
**Date:** 2026-06-02 · **Status:** done
|
||
|
||
## Outcome (measured)
|
||
|
||
| Metric | Before | After |
|
||
|---|---|---|
|
||
| `target/debug/deps` | 1.5 GB | **629 MB** (−58%) |
|
||
| Integration-test binaries | 26 | **2** (`it` + `typing_surface_matrix`) |
|
||
| Clean test build | 22.9 s | 22.4 s |
|
||
| Lib-edit relink | 13.3 s | 12.4 s |
|
||
| Tests | 2151/0/1 | 2151/0/1 (identical) |
|
||
|
||
cargo auto-detected `tests/it/main.rs` as the `it` target — no
|
||
`[[test]]` entry, no fixups, no warnings.
|
||
|
||
**Correction to the build-time hypothesis:** the expected relink
|
||
speed-up (≈13 s → ≈5 s) did *not* materialise. Wall-clock is dominated
|
||
by *compiling* (the lib + ~290 deps + the test code's
|
||
codegen/monomorphisation), not by *linking*. Consolidation collapses 26
|
||
link steps into 2 — which is why **disk** drops 58 % (each link emits a
|
||
whole standalone binary) — but compile work is unchanged, so build time
|
||
barely moves. **The real, durable win is disk, not speed.** Minor cost:
|
||
editing a single test file now recompiles the whole `it` module set
|
||
(test-only edits marginally slower; lib edits marginally faster — a
|
||
wash). Kept for the disk benefit, which is exactly the concern that
|
||
prompted it.
|
||
|
||
## Why
|
||
|
||
Each top-level `tests/*.rs` is a separate integration-test *crate* →
|
||
its own binary, each statically linking the bundled engine + every
|
||
dependency + debug info. There are **26** of them. With incremental
|
||
disabled (build-hygiene change, commit `42f9553`), an edit to the lib
|
||
forces **all 26 to relink**.
|
||
|
||
**Measured baseline:**
|
||
- Lib-edit relink (touch `src/app.rs`, `cargo test --no-run`): **13.3 s**
|
||
- Clean build of all test targets (`cargo clean && cargo test --no-run`): **22.9 s**
|
||
- `target/debug/deps`: **1.5 GB**
|
||
|
||
Collapsing to one binary turns 26 links into 1 — the dominant cost in
|
||
both numbers.
|
||
|
||
## Approach
|
||
|
||
The pattern already used by `tests/typing_surface_matrix.rs` (one
|
||
binary that `mod`-includes the `tests/typing_surface/` modules). Apply
|
||
it to the other 25 standalone files.
|
||
|
||
Feasibility pre-checks (done, all clear):
|
||
- **No top-level integration test uses insta** → moving files causes
|
||
no snapshot-path churn.
|
||
- **No crate-level `#![…]` attributes** to hoist.
|
||
- **No shared `mod common;` helpers** to relocate; the 25 files are
|
||
self-contained (`use rdbms_playground::…`), no inter-file `mod`.
|
||
|
||
## Steps
|
||
|
||
1. `mkdir tests/it`.
|
||
2. `git mv` the 25 standalone `tests/*.rs` → `tests/it/<name>.rs`
|
||
(everything except `typing_surface_matrix.rs`, which stays as its
|
||
own already-consolidated binary).
|
||
3. Create `tests/it/main.rs` = `mod <name>;` for all 25.
|
||
4. Confirm cargo builds it as one target (`tests/it/main.rs`
|
||
auto-detection; add an explicit `[[test]] name="it"` only if not).
|
||
5. Fix anything the combined build surfaces (expected minimal): a
|
||
stray `use crate::` self-ref, or a clippy `dead_code`/unused-import
|
||
the per-crate split had hidden.
|
||
|
||
**End state: 2 integration-test binaries (`it` + `typing_surface_matrix`)
|
||
instead of 26.**
|
||
|
||
## Verification / go-no-go gate
|
||
|
||
- Full `cargo test` → identical **2151 / 0 / 1**.
|
||
- `cargo clippy --all-targets -- -D warnings` clean.
|
||
- Re-measure relink + clean build; record before/after in the commit.
|
||
- If the after-numbers aren't materially better, **revert** (all
|
||
`git mv`, trivially reversible).
|
||
|
||
## Tradeoff (accepted)
|
||
|
||
Lose per-crate isolation: a compile error fails the whole `it` binary,
|
||
and the 25 files share one crate namespace (module-scoped — no name
|
||
clashes). Negligible for a solo teaching project; the build-speed win
|
||
is the priority.
|