Add tests and use null context

actions-languageservice/src/validate.expressions.test.ts

@@ -224,6 +224,67 @@ jobs:
     });
   });
 
+  describe("job context", () => {
+    it("job.status", async () => {
+      const input = `
+on: push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo \${{ job.status }}
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+
+      expect(result).toEqual([]);
+    });
+
+    it("job.container", async () => {
+      const input = `
+on: push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: node:14.16
+      env:
+        NODE_ENV: development
+      ports:
+        - 80
+      volumes:
+        - my_docker_volume:/volume_mount
+      options: --cpus 1
+    steps:
+      - run: echo \${{ job.container }}
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+
+      expect(result).toEqual([]);
+    });
+
+    it("job.services.<service_id>", async () => {
+      const input = `
+on: push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    services:
+      nginx:
+        image: nginx
+        ports:
+          - 8080:80
+    steps:
+      - run: echo \${{ job.services.nginx }}
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+
+      expect(result).toEqual([]);
+    });
+  });
+
   describe("strategy context", () => {
     it("reference within a matrix job", async () => {
       const input = `