Clear all possible token env vars for token accessor test. (ossf#3347)

Signed-off-by: Spencer Schrock <[email protected]>

clients/githubrepo/roundtripper/tokens/accessor.go

@@ -23,6 +23,9 @@ import (
 // githubAuthServer is the RPC URL for the token server.
 const githubAuthServer = "GITHUB_AUTH_SERVER"
 
+// env variables from which GitHub auth tokens are read, in order of precedence.
+var githubAuthTokenEnvVars = []string{"GITHUB_AUTH_TOKEN", "GITHUB_TOKEN", "GH_TOKEN", "GH_AUTH_TOKEN"}
+
 // TokenAccessor interface defines a `retrieve-once` data structure.
 // Implementations of this interface must be thread-safe.
 type TokenAccessor interface {
@@ -31,8 +34,7 @@ type TokenAccessor interface {
 }
 
 func readGitHubTokens() (string, bool) {
-	githubAuthTokens := []string{"GITHUB_AUTH_TOKEN", "GITHUB_TOKEN", "GH_TOKEN", "GH_AUTH_TOKEN"}
-	for _, name := range githubAuthTokens {
+	for _, name := range githubAuthTokenEnvVars {
 		if token, exists := os.LookupEnv(name); exists && token != "" {
 			return token, exists
 		}
@@ -45,7 +47,7 @@ func MakeTokenAccessor() TokenAccessor {
 	if value, exists := readGitHubTokens(); exists {
 		return makeRoundRobinAccessor(strings.Split(value, ","))
 	}
-	if value, exists := os.LookupEnv(githubAuthServer); exists {
+	if value, exists := os.LookupEnv(githubAuthServer); exists && value != "" {
 		return makeRPCAccessor(value)
 	}
 	return nil

clients/githubrepo/roundtripper/tokens/accessor_test.go

@@ -40,16 +40,17 @@ func TestMakeTokenAccessor(t *testing.T) {
 			useServer: true,
 		},
 	}
-	t.Setenv("GITHUB_AUTH_TOKEN", "")
-	t.Setenv("GITHUB_TOKEN", "")
+	// clear all env variables devs may have defined, or the test will fail locally
+	for _, envVar := range githubAuthTokenEnvVars {
+		t.Setenv(envVar, "")
+	}
+	t.Setenv(githubAuthServer, "")
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			switch {
 			case tt.useGitHubToken:
-				t.Helper()
 				testToken(t)
 			case tt.useServer:
-				t.Helper()
 				testServer(t)
 			default:
 				got := MakeTokenAccessor()