Add tests

bundle/config/mutator/validate_workspace_host.go

@@ -23,7 +23,7 @@ func (m *validateWorkspaceHost) Apply(ctx context.Context, b *bundle.Bundle) dia
 	target_host := b.Config.Workspace.Host
 
 	if env_host != "" && target_host != "" && env_host != target_host {
-		return diag.Errorf("Target host and DATABRICKS_HOST environment variable mismatch")
+		return diag.Errorf("target host and DATABRICKS_HOST environment variable mismatch")
 	}
 
 	return nil

bundle/config/mutator/validate_workspace_host_test.go

@@ -0,0 +1,43 @@
+package mutator
+
+import (
+	"context"
+	"testing"
+
+	"github.com/databricks/cli/bundle"
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/bundle/env"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateValidateWorkspaceHost(t *testing.T) {
+	host := "https://host.databricks.com"
+	b := &bundle.Bundle{
+		Config: config.Root{
+			Workspace: config.Workspace{
+				Host: host,
+			},
+		},
+	}
+	t.Setenv(env.HostVariable, host)
+
+	m := ValidateWorkspaceHost()
+	diags := bundle.Apply(context.Background(), b, m)
+	assert.NoError(t, diags.Error())
+}
+
+func TestValidateValidateWorkspaceHostMismatch(t *testing.T) {
+	b := &bundle.Bundle{
+		Config: config.Root{
+			Workspace: config.Workspace{
+				Host: "https://target-host.databricks.com",
+			},
+		},
+	}
+	t.Setenv(env.HostVariable, "https://env-host.databricks.com")
+
+	m := ValidateWorkspaceHost()
+	diags := bundle.Apply(context.Background(), b, m)
+	expectedError := "target host and DATABRICKS_HOST environment variable mismatch"
+	assert.EqualError(t, diags.Error(), expectedError)
+}