Unit tests failing on GOOGLE_APPLICATION_CREDENTIALS not set

[dfajmon]

Running test/run_unit.sh now fails on sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider
Error prints include additional

... google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information ...

Output of unit tests run localy

+ readonly PKGDIR=sigs.k8s.io/gcp-filestore-csi-driver
+ PKGDIR=sigs.k8s.io/gcp-filestore-csi-driver
+ go version
go version go1.23.6 linux/amd64
+ go test -mod=vendor -timeout 30s sigs.k8s.io/gcp-filestore-csi-driver/cmd/...
?       sigs.k8s.io/gcp-filestore-csi-driver/cmd        [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/cmd/lockrelease    [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/cmd/webhook        [no test files]
+ go test -mod=vendor -timeout 30s sigs.k8s.io/gcp-filestore-csi-driver/pkg/...
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/apis/multishare        [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/apis/multishare/v1     [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/clientset/versioned     [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/clientset/versioned/fake        [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/clientset/versioned/typed/multishare/v1 [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/clientset/versioned/scheme      [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/clientset/versioned/typed/multishare/v1/fake    [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/informers/externalversions      [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/informers/externalversions/internalinterfaces   [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/informers/externalversions/multishare   [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/informers/externalversions/multishare/v1        [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/client/listers/multishare/v1   [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider/metadata        [no test files]
?       sigs.k8s.io/gcp-filestore-csi-driver/pkg/common [no test files]
W0930 14:19:18.822433  107035 cloud.go:123] GOOGLE_APPLICATION_CREDENTIALS env var not set
I0930 14:19:18.822500  107035 cloud.go:125] Using DefaultTokenSource <nil>
W0930 14:19:18.822568  107035 cloud.go:123] GOOGLE_APPLICATION_CREDENTIALS env var not set
I0930 14:19:18.822571  107035 cloud.go:125] Using DefaultTokenSource <nil>
W0930 14:19:18.822602  107035 cloud.go:123] GOOGLE_APPLICATION_CREDENTIALS env var not set
I0930 14:19:18.822605  107035 cloud.go:125] Using DefaultTokenSource <nil>
W0930 14:19:18.822654  107035 cloud.go:123] GOOGLE_APPLICATION_CREDENTIALS env var not set
I0930 14:19:18.822657  107035 cloud.go:125] Using DefaultTokenSource <nil>
--- FAIL: TestValidateResourceTags (0.00s)
    --- FAIL: TestValidateResourceTags/valid_tags_string (0.00s)
        user_tags_test.go:337: ValidateResourceTags(): got: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information, wantErr: 
    --- FAIL: TestValidateResourceTags/non_existent_tag (0.00s)
        user_tags_test.go:337: ValidateResourceTags(): got: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information, wantErr: failed to fetch openshift/test3/test3 tag: googleapi: Error 404: openshift/test3/test3 tag does not exist.
    --- FAIL: TestValidateResourceTags/gapi_tag_not_exist_error (0.00s)
        user_tags_test.go:337: ValidateResourceTags(): got: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information, wantErr: [openshift/test4/test4] tag(s) provided in unit test does not exist
    --- FAIL: TestValidateResourceTags/invalid_tag_configured(without_parent_ID) (0.00s)
        user_tags_test.go:337: ValidateResourceTags(): got: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information, wantErr: test4/test4 tag provided in unit test not in expected format(<parentID/tagKey_name/tagValue_name>)
W0930 14:19:18.822738  107035 cloud.go:123] GOOGLE_APPLICATION_CREDENTIALS env var not set
I0930 14:19:18.822741  107035 cloud.go:125] Using DefaultTokenSource <nil>
--- FAIL: TestNewTagValuesClient (0.00s)
    user_tags_test.go:355: newTagValuesClient(): failed to create tag values client: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xd88732]

goroutine 55 [running]:
testing.tRunner.func1.2({0xe870e0, 0x18c83e0})
        /home/dfajmon/.gimme/versions/go1.23.6.linux.amd64/src/testing/testing.go:1632 +0x230
testing.tRunner.func1()
        /home/dfajmon/.gimme/versions/go1.23.6.linux.amd64/src/testing/testing.go:1635 +0x35e
panic({0xe870e0?, 0x18c83e0?})
        /home/dfajmon/.gimme/versions/go1.23.6.linux.amd64/src/runtime/panic.go:785 +0x132
sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider.(*tagValuesClient).close(0xc000402900?)
        /home/dfajmon/openshift/gcp-filestore-csi-driver/pkg/cloud_provider/user_tags.go:392 +0x12
sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider.TestNewTagValuesClient(0xc000472680)
        /home/dfajmon/openshift/gcp-filestore-csi-driver/pkg/cloud_provider/user_tags_test.go:358 +0x15a
testing.tRunner(0xc000472680, 0x105c228)
        /home/dfajmon/.gimme/versions/go1.23.6.linux.amd64/src/testing/testing.go:1690 +0xf4
created by testing.(*T).Run in goroutine 1
        /home/dfajmon/.gimme/versions/go1.23.6.linux.amd64/src/testing/testing.go:1743 +0x390
FAIL    sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider 0.010s
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/cloud_provider/file    (cached)
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/csi_driver     (cached)
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/metrics        (cached)
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/releaselock    (cached)
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/util   (cached)
ok      sigs.k8s.io/gcp-filestore-csi-driver/pkg/webhook        (cached)
FAIL

The ValidateResourceTags is eventually trying to generate token here https://github.com/kubernetes-sigs/gcp-filestore-csi-driver/blob/master/pkg/cloud_provider/cloud.go#L106 and adds error of the not set env.

That is later compared with the expected error and fails.

Are unit tests expected to have this env set?

[dfajmon]

Found the reason and solution #905