chore: update test to handle case when env var is set (#304)

* chore: update test to handle case when env var is set

- Fixes #303

* revert

* delete env vars in setupTests.js

* remove newline

tests/setupTests.js

@@ -8,6 +8,18 @@ switch (process.env.NOCK_ENV || ``) {
   case `record`:
   case `replay`:
     beforeEach(() => {
+      // To ensure we test the default behavior, we must remove these env vars
+      // in case the local machine already set these values.
+      delete process.env.COREPACK_DEFAULT_TO_LATEST;
+      delete process.env.COREPACK_ENABLE_NETWORK;
+      delete process.env.COREPACK_ENABLE_PROJECT_SPEC;
+      delete process.env.COREPACK_ENABLE_STRICT;
+      delete process.env.COREPACK_HOME;
+      delete process.env.COREPACK_NPM_REGISTRY;
+      delete process.env.COREPACK_NPM_TOKEN;
+      delete process.env.COREPACK_NPM_USERNAME;
+      delete process.env.FORCE_COLOR;
+
       process.env.RUN_CLI_ID = 0;
       process.env.NOCK_FILE_NAME = crypto
         .createHash(`md5`)