Fix action binary compilation and add CI coverage (#4)

env.vars() was interpreted as env.vars.apply() which requires a USize
argument. The action/ package was never compiled during development or
CI, so this went undetected. Fix to env.vars (field access).

Add build-action step to the PR workflow so the action binary is
compiled alongside the tests. Also add a docker-build job that builds
the full Docker image, catching Dockerfile and static linking issues.

Author: SeanTAllen

.github/workflows/pr.yml

@@ -26,3 +26,13 @@ jobs:
       - uses: actions/checkout@v6.0.2
       - name: Test
         run: make test ssl=libressl config=debug
+      - name: Build action binary
+        run: make build-action ssl=libressl config=debug
+
+  docker-build:
+    name: Verify Docker image builds
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6.0.2
+      - name: Build Docker image
+        run: docker build .

action/main.pony

@@ -7,7 +7,7 @@ use ssl = "ssl/net"
 
 actor \nodoc\ Main
   new create(env: Env) =>
-    let vars = _parse_env_vars(env.vars())
+    let vars = _parse_env_vars(env.vars)
     match zulip.InputParser(vars)
     | let input: zulip.Input =>
       match courier.URL.parse(input.organization_url)