Properly run wasm32-unknown-unknown tests on CI

Author: gnzlbg

azure-pipelines.yml

@@ -39,17 +39,9 @@ jobs:
           TARGET: powerpc64le-unknown-linux-gnu
         x86_64:
           TARGET: x86_64-unknown-linux-gnu
-
-  - job: wasm
-    pool:
-      vmImage: ubuntu-16.04
-    steps:
-      - template: ci/azure-install-rust.yml
-      - script: rustup target add wasm32-unknown-unknown
-        displayName: "Install rust wasm target"
-      - script: sh ./ci/run.sh wasm32-unknown-unknown
-    variables:
-      TOOLCHAIN: nightly
+        wasm32:
+          TARGET: wasm32-unknown-unknown
+          TOOLCHAIN: nightly
 
   - job: rustfmt
     pool:

ci/docker/wasm32-unknown-unknown/Dockerfile

@@ -0,0 +1,24 @@
+FROM ubuntu:18.04
+
+RUN apt-get update -y && apt-get install -y --no-install-recommends \
+  ca-certificates \
+  clang \
+  cmake \
+  curl \
+  git \
+  libc6-dev \
+  make \
+  python \
+  xz-utils
+
+# Install `wasm2wat`
+RUN git clone --recursive https://github.com/WebAssembly/wabt
+RUN make -C wabt -j$(nproc)
+ENV PATH=$PATH:/wabt/bin
+
+# Install `node`
+RUN curl https://nodejs.org/dist/v12.0.0/node-v12.0.0-linux-x64.tar.xz | tar xJf -
+ENV PATH=$PATH:/node-v12.0.0-linux-x64/bin
+
+COPY docker/wasm32-unknown-unknown/wasm-entrypoint.sh /wasm-entrypoint.sh
+ENTRYPOINT ["/wasm-entrypoint.sh"]

ci/docker/wasm32-unknown-unknown/wasm-entrypoint.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+set -e
+
+# Download an appropriate version of wasm-bindgen based off of what's being used
+# in the lock file. Ideally we'd use `wasm-pack` at some point for this!
+version=$(grep -A 1 'name = "wasm-bindgen"' Cargo.lock | grep version)
+version=$(echo $version | awk '{print $3}' | sed 's/"//g')
+curl -L https://github.com/rustwasm/wasm-bindgen/releases/download/$version/wasm-bindgen-$version-x86_64-unknown-linux-musl.tar.gz \
+   | tar xzf - -C target
+export PATH=$PATH:`pwd`/target/wasm-bindgen-$version-x86_64-unknown-linux-musl
+export CARGO_TARGET_WASM32_UNKNOWN_UNKNOWN_RUNNER=wasm-bindgen-test-runner
+export NODE_ARGS=--experimental-wasm-simd
+
+exec "$@"

ci/run-docker.sh

@@ -12,7 +12,7 @@ run() {
     # will be owned by root
     mkdir -p target
 
-    docker build -t $target ci/docker/$target
+    docker build -t $target -f ci/docker/$target/Dockerfile ci/
     docker run \
            --rm \
            --user $(id -u):$(id -g) \