test: cover Go-side SNYK_REQUEST_CONCURRENCY plumbing

Add unit coverage for fillEnvironmentFromConfig's handling of the new
ConfigKeyRequestConcurrency: forwards a user-set value to the legacy
CLI as SNYK_INTERNAL_REQUEST_CONCURRENCY, omits the internal env when
unset, and strips a user-provided internal env so Go remains the
source of truth.

Author: bgardiner

cliv2/internal/cliv2/cliv2_test.go

@@ -270,6 +270,52 @@ func Test_PrepareV1EnvironmentVariables_OnlyExplicitlySetValues(t *testing.T) {
 	})
 }
 
+func Test_PrepareV1EnvironmentVariables_RequestConcurrency(t *testing.T) {
+	t.Run("forwards resolved value to internal env when alt key is set via env", func(t *testing.T) {
+		t.Setenv("SNYK_REQUEST_CONCURRENCY", "17")
+
+		config := configuration.NewWithOpts(configuration.WithAutomaticEnv())
+		config.AddAlternativeKeys(cliv2.ConfigKeyRequestConcurrency, []string{"snyk_request_concurrency"})
+
+		actual, err := cliv2.PrepareV1EnvironmentVariables([]string{}, "foo", "bar", "proxy", "cacertlocation", config, []string{})
+
+		assert.Nil(t, err)
+		assert.Contains(t, actual, constants.SNYK_INTERNAL_REQUEST_CONCURRENCY_ENV+"=17")
+	})
+
+	t.Run("does not set internal env when alt key is unset", func(t *testing.T) {
+		// guard against a stray env var leaking into the test environment
+		t.Setenv("SNYK_REQUEST_CONCURRENCY", "")
+		_ = os.Unsetenv("SNYK_REQUEST_CONCURRENCY")
+
+		config := configuration.NewWithOpts(configuration.WithAutomaticEnv())
+		config.AddAlternativeKeys(cliv2.ConfigKeyRequestConcurrency, []string{"snyk_request_concurrency"})
+
+		actual, err := cliv2.PrepareV1EnvironmentVariables([]string{}, "foo", "bar", "proxy", "cacertlocation", config, []string{})
+
+		assert.Nil(t, err)
+		for _, kv := range actual {
+			assert.NotContains(t, kv, constants.SNYK_INTERNAL_REQUEST_CONCURRENCY_ENV+"=")
+		}
+	})
+
+	t.Run("user-set internal env is stripped before Go reapplies it", func(t *testing.T) {
+		t.Setenv("SNYK_REQUEST_CONCURRENCY", "9")
+
+		config := configuration.NewWithOpts(configuration.WithAutomaticEnv())
+		config.AddAlternativeKeys(cliv2.ConfigKeyRequestConcurrency, []string{"snyk_request_concurrency"})
+
+		// Simulate a user trying to bypass Go config by setting the internal var directly.
+		input := []string{constants.SNYK_INTERNAL_REQUEST_CONCURRENCY_ENV + "=999"}
+
+		actual, err := cliv2.PrepareV1EnvironmentVariables(input, "foo", "bar", "proxy", "cacertlocation", config, []string{})
+
+		assert.Nil(t, err)
+		assert.Contains(t, actual, constants.SNYK_INTERNAL_REQUEST_CONCURRENCY_ENV+"=9")
+		assert.NotContains(t, actual, constants.SNYK_INTERNAL_REQUEST_CONCURRENCY_ENV+"=999")
+	})
+}
+
 func Test_PrepareV1EnvironmentVariables_Fail_DontOverrideExisting(t *testing.T) {
 	orgid := "orgid"
 	testapi := "https://api.snyky.io"