Add test case for half-configured v2 config

internal/provider/provider.go

@@ -161,10 +161,12 @@ func (p *HoneycombioProvider) Configure(ctx context.Context, req provider.Config
 	} else if (keyID != "" && keySecret == "") || (keyID == "" && keySecret != "") {
 		resp.Diagnostics.AddError(
 			"Unable to initialize Honeycomb provider",
-			"The provider requires both a Honeycomb API Key ID and Secret pair. "+
+			"The provider requires both a Honeycomb API Key ID and Secret. "+
 				"Set them both in the configuration or via the HONEYCOMB_KEY_ID and HONEYCOMB_KEY_SECRET"+
-				"environment variables.",
+				"environment variables. "+
+				"If you believe both are already set, ensure the values are not empty.",
 		)
+		return
 	}
 
 	if !initv1Client && !initv2Client {

internal/provider/provider_test.go

@@ -165,6 +165,30 @@ resource "honeycombio_api_key" "test" {
 		})
 	})
 
+	t.Run("fails when only half of v2 configuration is set", func(t *testing.T) {
+		resource.Test(t, resource.TestCase{
+			ProtoV5ProviderFactories: testAccProtoV5MuxServerFactory,
+			Steps: []resource.TestStep{
+				{
+					PreConfig: func() {
+						t.Setenv("HONEYCOMB_API_KEY", "")
+						t.Setenv("HONEYCOMB_KEY_SECRET", "")
+					},
+					Config: `
+# TODO: replace with v2-client data source
+resource "honeycombio_api_key" "test" {
+  name = "test"
+  type = "ingest"
+
+  environment_id = "1"
+}`,
+					PlanOnly:    true,
+					ExpectError: regexp.MustCompile(`provider requires both a Honeycomb API Key ID and Secret`),
+				},
+			},
+		})
+	})
+
 	t.Run("fails when no clients configured", func(t *testing.T) {
 		resource.Test(t, resource.TestCase{
 			ProtoV5ProviderFactories: testAccProtoV5MuxServerFactory,