Adds tests for

__test__/projects/CachingProjectDataSource.test.ts

@@ -0,0 +1,42 @@
+import Project from "../../src/features/projects/domain/Project"
+import CachingProjectDataSource from "../../src/features/projects/domain/CachingProjectDataSource"
+
+test("It caches projects read from the data source", async () => {
+  const projects = [{
+    id: "foo",
+    name: "foo",
+    versions: [{
+      id: "bar",
+      name: "bar",
+      specifications: [{
+        id: "baz.yml",
+        name: "baz.yml",
+        url: "https://example.com/baz.yml"
+      }]
+    }, {
+      id: "hello",
+      name: "hello",
+      specifications: [{
+        id: "world.yml",
+        name: "world.yml",
+        url: "https://example.com/world.yml"
+      }]
+    }]
+  }]
+  let cachedProjects: Project[] | undefined
+  const sut = new CachingProjectDataSource({
+    async getProjects() {
+      return projects
+    }
+  }, {
+    async getProjects() {
+      return []
+    },
+    async storeProjects(projects) {
+      cachedProjects = projects
+    },
+    async deleteProjects() {}
+  })
+  await sut.getProjects()
+  expect(cachedProjects).toEqual(projects)
+})