Workflow context getters (#39)

- Add GetWorkflowID() which takes a context and, if a DBOS one, returns
the workflowID (otherwise an error)
- Stop exporting some stuff
- operation -> step rename 
- add missing `dbos_test.go` file
- perform DBOS migrations in an isolated schema migration table

Author: maxdml

dbos/dbos.go

@@ -71,11 +71,11 @@ type Config struct {
 	AdminServer bool
 }
 
-// ProcessConfig merges configuration from two sources in order of precedence:
+// processConfig merges configuration from two sources in order of precedence:
 // 1. programmatic configuration
 // 2. environment variables
 // Finally, it applies default values if needed.
-func ProcessConfig(inputConfig *Config) (*Config, error) {
+func processConfig(inputConfig *Config) (*Config, error) {
 	// First check required fields
 	if len(inputConfig.DatabaseURL) == 0 {
 		return nil, fmt.Errorf("missing required config field: databaseURL")
@@ -133,7 +133,7 @@ func Initialize(inputConfig Config) error {
 	}
 
 	// Load & process the configuration
-	config, err := ProcessConfig(&inputConfig)
+	config, err := processConfig(&inputConfig)
 	if err != nil {
 		return newInitializationError(err.Error())
 	}

dbos/dbos_test.go

@@ -0,0 +1,87 @@
+package dbos
+
+import (
+	"context"
+	"encoding/hex"
+	"maps"
+	"testing"
+)
+
+func TestConfigValidationErrorTypes(t *testing.T) {
+	databaseURL := getDatabaseURL(t)
+
+	t.Run("FailsWithoutAppName", func(t *testing.T) {
+		config := Config{
+			DatabaseURL: databaseURL,
+		}
+
+		err := Initialize(config)
+		if err == nil {
+			t.Fatal("expected error when app name is missing, but got none")
+		}
+
+		dbosErr, ok := err.(*DBOSError)
+		if !ok {
+			t.Fatalf("expected DBOSError, got %T", err)
+		}
+
+		if dbosErr.Code != InitializationError {
+			t.Fatalf("expected InitializationError code, got %v", dbosErr.Code)
+		}
+
+		expectedMsg := "Error initializing DBOS Transact: missing required config field: appName"
+		if dbosErr.Message != expectedMsg {
+			t.Fatalf("expected error message '%s', got '%s'", expectedMsg, dbosErr.Message)
+		}
+	})
+
+	t.Run("FailsWithoutDatabaseURL", func(t *testing.T) {
+		config := Config{
+			AppName: "test-app",
+		}
+
+		err := Initialize(config)
+		if err == nil {
+			t.Fatal("expected error when database URL is missing, but got none")
+		}
+
+		dbosErr, ok := err.(*DBOSError)
+		if !ok {
+			t.Fatalf("expected DBOSError, got %T", err)
+		}
+
+		if dbosErr.Code != InitializationError {
+			t.Fatalf("expected InitializationError code, got %v", dbosErr.Code)
+		}
+
+		expectedMsg := "Error initializing DBOS Transact: missing required config field: databaseURL"
+		if dbosErr.Message != expectedMsg {
+			t.Fatalf("expected error message '%s', got '%s'", expectedMsg, dbosErr.Message)
+		}
+	})
+}
+func TestAppVersion(t *testing.T) {
+	if _, err := hex.DecodeString(_APP_VERSION); err != nil {
+		t.Fatalf("APP_VERSION is not a valid hex string: %v", err)
+	}
+
+	// Save the original registry content
+	originalRegistry := make(map[string]workflowRegistryEntry)
+	maps.Copy(originalRegistry, registry)
+
+	// Restore the registry after the test
+	defer func() {
+		registry = originalRegistry
+	}()
+
+	// Replace the registry and verify the hash is different
+	registry = make(map[string]workflowRegistryEntry)
+
+	WithWorkflow(func(ctx context.Context, input string) (string, error) {
+		return "new-registry-workflow-" + input, nil
+	})
+	hash2 := computeApplicationVersion()
+	if _APP_VERSION == hash2 {
+		t.Fatalf("APP_VERSION hash did not change after replacing registry")
+	}
+}