From 3bd9604aa444ed53151fe60c95c77bc051a30c99 Mon Sep 17 00:00:00 2001
From: Erwan Or <erwanor@penumbralabs.xyz>
Date: Wed, 27 Mar 2024 13:20:29 -0400
Subject: [PATCH] ci: add wasm check for component crates

Back in [0] we removed the wasm crate from the monorepo, so that the web
team could own it and iterate more quickly. We also purged associated
testing, however, so we missed some breakage around the release of
v0.70.0. This check attempts to restore some visibility into the
potential of breaking APIs relevant to web work.

[0] https://github.com/penumbra-zone/penumbra/issues/3819
---
 .github/workflows/rust.yml               | 10 +++++
 deployments/scripts/check-wasm-compat.sh | 50 ++++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100755 deployments/scripts/check-wasm-compat.sh

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 9d1dff519f..646d7aa973 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -9,12 +9,18 @@ jobs:
       - uses: actions/checkout@v4
         with:
           lfs: true
+
       - name: Install rust toolchain
         uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: wasm32-unknown-unknown
+
       - name: Install nextest
         uses: taiki-e/install-action@nextest
+
       - name: Load rust cache
         uses: astriaorg/buildjet-rust-cache@v2.5.1
+
       - name: Run cargo check, failing on warnings
         run: cargo check --release --all-targets
         env:
@@ -22,6 +28,9 @@ jobs:
           # we must duplicate the rustflags from `.cargo/config.toml`.
           RUSTFLAGS: "-D warnings --cfg tokio_unstable"
 
+      - name: Check wasm compatibility
+        run: ./deployments/scripts/check-wasm-compat.sh
+
       # If a dependency was modified, Cargo.lock may flap if not committed.
       - name: Check for diffs
         shell: bash
@@ -35,6 +44,7 @@ jobs:
           else
               echo "OK: no uncommitted changes detected"
           fi
+
       - name: Run tests with nextest
         run: cargo nextest run --release --features migration
         env:
diff --git a/deployments/scripts/check-wasm-compat.sh b/deployments/scripts/check-wasm-compat.sh
new file mode 100755
index 0000000000..317b1b2aee
--- /dev/null
+++ b/deployments/scripts/check-wasm-compat.sh
@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# CI script for checking that the Penumbra monorepo does not accidentally
+# break compatibility with downstream web APIs, via the WASM crate.
+# Historically, this breakage has taken the form of inadvertently introducing
+# dependencies on std, e.g. via `mio`.
+set -euo pipefail
+
+
+# List of packages taken from web repo's wasm Cargo.toml:
+#
+#   ❯ rg ^penumbra packages/wasm/crate/Cargo.toml --no-line-number | cut -f1 -d' '  | sort
+#
+# should be periodically updated in order to keep parity.
+
+packages=(
+    penumbra-asset
+    penumbra-community-pool
+    penumbra-compact-block
+    penumbra-dex
+    penumbra-distributions
+    penumbra-fee
+    penumbra-funding
+    penumbra-governance
+    penumbra-ibc
+    penumbra-keys
+    penumbra-sct
+    penumbra-shielded-pool
+    penumbra-stake
+    penumbra-tct
+    penumbra-transaction
+    penumbra-txhash
+    # N.B. we can't include those ones because they rely on `getrandom`,
+    # but there's a `js` feature...
+    # decaf377-fmd
+    # decaf377-frost
+    # decaf377-ka
+    # penumbra-num
+    # penumbra-proof-params
+    # penumbra-proto
+)
+
+# We intentionally loop over the packages one by one to make error-reporting clearer.
+# Ostensibly this would be slow, but in CI with a warm cache it's quick.
+for p in "${packages[@]}" ; do
+    echo "Checking package for wasm compat: $p ..."
+    if ! cargo check --release --target wasm32-unknown-unknown --no-default-features --package "$p" ; then
+        >&2 echo "ERROR: package appears not to be wasm-compatible: '$p'"
+        exit 1
+    fi
+done