Remove calls to t.Setenv from integration tests

[pietern]

Changes

The Setenv helper function configures an environment variable and resets it to its original value when exiting the test scope. It is incompatible with running tests in parallel because it modifies process-wide state. The libs/env package defines functions to interact with the environment but records Setenv calls on a context.Context. This enables us to override/specialize the environment scoped to a context.

Pre-requisites for removing the t.Setenv calls:

• Make cmdio.NewIO accept a context and use it with libs/env
• Make all internal/testcli functions use a context

The rest of this change:

• Modifies integration tests to initialize a context to use if there wasn't already one
• Updates t.Setenv calls to use env.Set

Tests

n/a

[pietern]

It would be nicer to have a linter to prevent t.Setenv calls from the integration tests but I couldn't find one.

[github-actions]

If integration tests don't run automatically, an authorized user can run them manually by following the instructions below:

Trigger:
go/deco-tests-run/cli

Inputs:

• PR number: 2018
• Commit SHA: c2f8952055be140356d09814444a9c96f54596b4

Checks will be approved automatically on success.

[pietern]

The integration test TestFetchRepositoryInfoAPI failed because the cleanup reused the context.

The context already had a call to dbr.MockRuntime and the command execution calls dbr.DetectRuntime.

Use the fixture helpers instead of calling commands to fix this.

[denik]

Regarding "panic: dbr.DetectRuntime called twice on the same context" and changes in git_fetch_test.go.

While it does look cleaner to use helpers, it's weird that you can longer call "workspace mkdirs" followed by "workspace delete" - this suggests that something else is broken.

Another thing that is not clear is why does DetectRuntime fails when called second time instead of being idempotent?

[denik]

Why not fix the fixture helper instead to generate right path?

[pietern]

I tried this but there are assumptions elsewhere on the prefix not being included.

I'd like to address this in a separate PR and normalize on having the /Workspace prefix everywhere.

[pietern]

While it does look cleaner to use helpers, it's weird that you can longer call "workspace mkdirs" followed by "workspace delete" - this suggests that something else is broken.

This was prevented by the dbr.MockRuntime call sandwiched in between these calls.

It panics on the second call as a sanity check that we're not mocking/detecting multiple times.

[pietern]

The integration tests passed. Only the hooks to make a comment and mark the check as successful failed.