From c3a8e4ebbe36efb9f441211f9a34bd91dd4e0970 Mon Sep 17 00:00:00 2001
From: Ignat <ign.romanov@gmail.com>
Date: Thu, 4 Jun 2026 00:33:42 -0300
Subject: [PATCH 1/2] fix(codec): narrow vitest coverage include to src/**/*.ts

Eliminates "Failed to parse *.rs" warnings from @vitest/coverage-v8
when scanning src/ for uncovered files. Rust sources were never real
TS coverage targets; narrowing the glob has no effect on coverage %.

Adds reporter: ['text', 'lcov'] so lcov.info is emitted for codecov
upload (change 3 of A5 task).
---
 packages/codec/vitest.config.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/codec/vitest.config.ts b/packages/codec/vitest.config.ts
index 0cb1996..bf4a462 100644
--- a/packages/codec/vitest.config.ts
+++ b/packages/codec/vitest.config.ts
@@ -16,7 +16,8 @@ export default defineConfig({
       // enabled: true → `vitest run` always collects + gates coverage, so the
       // 80% threshold (Constitution X) is enforced by plain `pnpm -r test` in CI.
       enabled: true,
-      include: ['src/**'],
+      include: ['src/**/*.ts'],
+      reporter: ['text', 'lcov'],
       exclude: [
         'target/**',
         'pkg/**',

From 34ffeabb66a15506d0a52521dee2170516605ec4 Mon Sep 17 00:00:00 2001
From: Ignat <ign.romanov@gmail.com>
Date: Thu, 4 Jun 2026 00:33:52 -0300
Subject: [PATCH 2/2] ci: Rust coverage gate (cargo-llvm-cov 80%) + codecov
 upload
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Add llvm-tools-preview component to setup-rust-toolchain in
  lint-and-build job so cargo-llvm-cov instrumentation is available.
- Install cargo-llvm-cov via taiki-e/install-action (pinned SHA v2.81.3).
- Replace plain `cargo test` in lint-and-build with
  `cargo llvm-cov --fail-under-lines 80` (Constitution X gate).
  Other jobs (macos-sanity, vector-parity) keep plain cargo test.
- Add codecov/codecov-action upload (pinned SHA v6.0.1) for both
  rust-lcov.info (flag: rust) and packages/codec/coverage/lcov.info
  (flag: ts). fail_ci_if_error: false — codecov hiccup must not break CI.
- Add minimal codecov.yml: rust flag is informational (advisory),
  ts flag is default (blocking on threshold regression).

Measured Rust line coverage: 91.95% (gate: 80%).
---
 .github/workflows/ci.yml | 14 ++++++++++++--
 codecov.yml              | 16 ++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 codecov.yml

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3edaa2a..7e04996 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,17 +14,27 @@ jobs:
       - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e    # v6.4.0
         with: { node-version: 24, cache: pnpm }
       - uses: actions-rust-lang/setup-rust-toolchain@46268bd060767258de96ed93c1251119784f2ab6  # v1
-        with: { rustflags: "" }
+        with: { rustflags: "", components: "llvm-tools-preview" }
       - uses: Swatinem/rust-cache@e18b497796c12c097a38f9edb9d0641fb99eee32   # v2
       - run: rustup target add wasm32-unknown-unknown
       - name: Install wasm-pack 0.14.0
         run: cargo install wasm-pack --version 0.14.0 --locked
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@25435dc8dd3baed7417e0c96d3fe89013a5b2e09  # v2.81.3
+        with: { tool: cargo-llvm-cov }
       - run: pnpm install --frozen-lockfile
       - run: pnpm -r build
       - run: pnpm -r lint
       - run: pnpm -r test
       - run: cargo build --manifest-path packages/codec/Cargo.toml --release
-      - run: cargo test --manifest-path packages/codec/Cargo.toml
+      - name: Rust coverage gate (Constitution X — 80% line coverage)
+        run: cargo llvm-cov --manifest-path packages/codec/Cargo.toml --all-features --fail-under-lines 80 --lcov --output-path rust-lcov.info
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@e79a6962e0d4c0c17b229090214935d2e33f8354  # v6.0.1
+        with:
+          files: rust-lcov.info,packages/codec/coverage/lcov.info
+          flags: rust,ts
+          fail_ci_if_error: false
       - name: Assert size budgets
         run: bash scripts/assert-size.sh
         working-directory: packages/codec
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 0000000..d5def11
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,16 @@
+coverage:
+  status:
+    patch:
+      rust:
+        informational: true
+    project:
+      rust:
+        informational: true
+
+flags:
+  rust:
+    paths:
+      - packages/codec/src/
+  ts:
+    paths:
+      - packages/codec/src/