CAS-2552 — Plugin-dep symmetry check

Saga the Watchful — Ops & Infrastructure

In one breath

check-tauri-plugin-symmetry.sh runs in CI and pre-commit to ensure every JS-side Tauri plugin has a matching Rust entry — preventing the class of silent runtime failure that caused CAS-2516.

By the end of this chapter you’ll understand:

• What three-way symmetry the script enforces and where it runs (CI, pre-commit, and manual)
• How the exemption mechanism works for plugins that are intentionally Rust-only
• The four steps required when adding any new Tauri plugin so the check exits 0

CAS-2552 — Plugin-dep symmetry check

Shipped: 2026-05-13 (PR #658, feat(CAS-2556))
Root cause it prevents: CAS-2516 — iOS submit silently fell through to local mode because @tauri-apps/plugin-os existed in package.json but tauri-plugin-os was missing from Cargo.toml. The plugin call threw, the catch returned false (wrong default), and submit used the wrong path on iPhone.

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What was added

scripts/check-tauri-plugin-symmetry.sh — a build-time invariant checker that enforces three-way symmetry across the plugin dependency graph:

@tauri-apps/plugin-*  (package.json)
tauri-plugin-*        (src-tauri/Cargo.toml)

Any @tauri-apps/plugin-* in package.json must have a matching tauri-plugin-* in Cargo.toml, and vice versa (with an explicit exemption list for plugins that are Rust-only by design).

Exits 0 on full symmetry, 1 with an actionable diff when there is a mismatch.

Where it runs

• CI (.github/workflows/ci.yml) — blocks the build on any plugin asymmetry.
• Pre-commit (deno.json) — catches it before push.
• Manual: bash scripts/check-tauri-plugin-symmetry.sh from the repo root.

Exemption mechanism

RUST_ONLY_PLUGINS array at the top of the script lists plugins that live in Cargo but have no @tauri-apps/plugin-* counterpart by design. Each entry must include a comment explaining why the JS side is absent.

Current exemption: plugin-deep-link (frontend uses a custom event bridge; no @tauri-apps/plugin-deep-link import).

Adding a new Tauri plugin

1. Add @tauri-apps/plugin-<name> to package.json.
2. Add tauri-plugin-<name> to src-tauri/Cargo.toml.
3. Add .plugin(tauri_plugin_<name>::init()) to src-tauri/src/lib.rs.
4. Run bash scripts/check-tauri-plugin-symmetry.sh — should exit 0.

Missing step 2 or 3 will fail CI and pre-commit.

See it as

A double-entry bookkeeping rule applied to plugin dependencies: every credit on the JS side must have a matching debit on the Rust side. The script is the auditor who checks both ledgers agree before any code ships. An unbalanced entry isn’t just a warning — it’s a build failure.

Recap

• check-tauri-plugin-symmetry.sh compares @tauri-apps/plugin-* in package.json against tauri-plugin-* in Cargo.toml and exits 1 with an actionable diff on any mismatch.
• The RUST_ONLY_PLUGINS exemption list covers plugins that intentionally have no JS counterpart; each entry requires an explanatory comment.
• The check runs in CI (blocking), as a pre-commit hook, and is available for manual execution — a new plugin that skips any of the four addition steps will be caught before it reaches TestFlight.

What changed {#what-changed}

This feature shipped in CAS-2552. See: CHANGELOG → 2026-05-18