refactor: use Teffen's solution for useEnv

test/unit/helpers.test.ts

@@ -1,5 +1,5 @@
 import { promises as fs } from "fs"
-import { tmpdir } from "../../test/utils/helpers"
+import { tmpdir, useEnv } from "../../test/utils/helpers"
 
 /**
  * This file is for testing test helpers (not core code).
@@ -12,3 +12,30 @@ describe("test helpers", () => {
     expect(fs.access(pathToTempDir)).resolves.toStrictEqual(undefined)
   })
 })
+
+describe("useEnv", () => {
+  beforeAll(() => {
+    jest.resetModules()
+    process.env.TEST_USE_ENV = "test environment variable"
+  })
+  afterAll(() => {
+    delete process.env.TEST_USE_ENV
+  })
+  it("should set and reset the env var", () => {
+    const envKey = "TEST_ENV_VAR"
+    const [setValue, resetValue] = useEnv(envKey)
+    setValue("hello-world")
+    expect(process.env[envKey]).toEqual("hello-world")
+    resetValue()
+    expect(process.env[envKey]).toEqual(undefined)
+  })
+  it("should set and reset the env var where a value was already set", () => {
+    const envKey = "TEST_USE_ENV"
+    expect(process.env[envKey]).toEqual("test environment variable")
+    const [setValue, resetValue] = useEnv(envKey)
+    setValue("hello there")
+    expect(process.env[envKey]).toEqual("hello there")
+    resetValue()
+    expect(process.env[envKey]).toEqual("test environment variable")
+  })
+})