Merge branch '43-dry-run'

CHANGELOG.md

@@ -2,17 +2,19 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
-## Unreleased
+## [5.1.0](https://github.com/elwinar/rambler/releases/tag/5.1.0) - 2019-08-28
+### Added
+- `dru-run` flag
 
 ## [5.0.0](https://github.com/elwinar/rambler/releases/tag/5.0.0) - 2019-05-26
 ### Added
 - PostgreSQL support for schemas
 ### Changed
 - It is no longer an error if no configuration file is provided as option and
-  the default one doesn't exists.
+  the default one doesn't exists
 ### Internal
 - Split the general configuration and the driver configuration to allow a
-  better structure.
+  better structure
 
 ## [4.2.1](https://github.com/elwinar/rambler/releases/tag/4.2.1) - 2018-08-09
 ### Fixed
@@ -51,7 +53,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [4.0.0](https://github.com/elwinar/rambler/releases/tag/4.0.0) - 2016-10-30
 ### Added
-- MySQL driver now use the migration name as primary key (necessary for Percona XtraDB clusters)
+- MySQL driver now use the migration name as primary key (necessary for Percona
+  XtraDB clusters)
 
 ## [3.4.0](https://github.com/elwinar/rambler/releases/tag/v3.4.0) - 2016-10-27
 ### Added
@@ -97,7 +100,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Removed
 - The command-line options to override the configuration
-- Possibility of using alternatives configuration file types (namely YAML and TOML)
+- Possibility of using alternatives configuration file types (namely YAML and
+  TOML)
 
 ### Fixed
 - Behavior of the transactions

README.md

@@ -200,6 +200,10 @@ Rambler will log a few important informations for monitoring what is happening
 on stdout. If you suspect something of being wrong, you can also use the debug
 mode by adding `--debug` to your command line.
 
+### Dry-run
+
+The `--dry-run` flag will print statements instead of executing them.
+
 ## CONTRIBUTORS
 
 - [cjhubert](https://github.com/cjhubert)

bootstrap.go

@@ -12,10 +12,10 @@ import (
 // Bootstrap do the initialization job, and finish by setting the
 // `service` global var that will be used by other commands.
 func Bootstrap(ctx *cli.Context) error {
-	return bootstrap(ctx.GlobalString("configuration"), ctx.GlobalString("environment"), ctx.GlobalBool("debug"))
+	return bootstrap(ctx.GlobalString("configuration"), ctx.GlobalString("environment"), ctx.GlobalBool("debug"), ctx.GlobalBool("dry-run"))
 }
 
-func bootstrap(configuration, environment string, debug bool) (err error) {
+func bootstrap(configuration, environment string, debug, dryRun bool) (err error) {
 	logger = log.NewLogger(func(l *log.Logger) {
 		l.PrintDebug = debug
 	})
@@ -42,7 +42,7 @@ func bootstrap(configuration, environment string, debug bool) (err error) {
 	}
 
 	logger.Debug("initializing service")
-	service, err = NewService(env)
+	service, err = NewService(env, dryRun)
 	if err != nil {
 		return fmt.Errorf("unable to initialize the migration service: %s", err)
 	}

bootstrap_test.go

@@ -41,7 +41,7 @@ func TestBootstrap(t *testing.T) {
 		service = nil
 		logger = nil
 
-		err := bootstrap(c.configuration, c.environment, false)
+		err := bootstrap(c.configuration, c.environment, false, false)
 		if (err != nil) != c.err {
 			t.Error("case", n, "got unexpected error:", err)
 			continue

main.go

@@ -48,6 +48,10 @@ func main() {
 			Name:  "debug",
 			Usage: "display debug messages",
 		},
+		cli.BoolFlag{
+			Name:  "dry-run",
+			Usage: "don't execute any statement, only display them",
+		},
 	}
 
 	app.Before = Bootstrap

service.go

@@ -21,12 +21,13 @@ var (
 // Service is the struct that gather operations to manipulate the
 // database and migrations on disk
 type Service struct {
-	conn driver.Conn
-	env  Environment
+	conn   driver.Conn
+	env    Environment
+	dryRun bool
 }
 
 // NewService initialize a new service with the given environment
-func NewService(env Environment) (*Service, error) {
+func NewService(env Environment, dryRun bool) (*Service, error) {
 	fi, err := os.Stat(env.Directory)
 	if err != nil {
 		return nil, fmt.Errorf("directory %s unavailable: %s", env.Directory, err.Error())
@@ -47,8 +48,9 @@ func NewService(env Environment) (*Service, error) {
 	}
 
 	return &Service{
-		conn: conn,
-		env:  env,
+		conn:   conn,
+		env:    env,
+		dryRun: dryRun,
 	}, nil
 }
 
@@ -118,12 +120,21 @@ func (s Service) Apply(migration *Migration) error {
 	}
 
 	for _, statement := range migration.Up() {
+		if s.dryRun {
+			logger.Info("statement: %s", statement)
+			continue
+		}
+
 		err := s.conn.Execute(statement)
 		if err != nil {
 			return fmt.Errorf("unable to apply migration %s: %s\n%s", migration.Name, err, statement)
 		}
 	}
 
+	if s.dryRun {
+		return nil
+	}
+
 	err := s.conn.AddApplied(migration.Name)
 	if err != nil {
 		return fmt.Errorf("unable to mark migration %s as applied: %s", migration.Name, err)
@@ -140,12 +151,21 @@ func (s Service) Reverse(migration *Migration) error {
 	}
 
 	for _, statement := range migration.Down() {
+		if s.dryRun {
+			logger.Info("statement: %s", statement)
+			continue
+		}
+
 		err := s.conn.Execute(statement)
 		if err != nil {
 			return fmt.Errorf("unable to reverse migration %s: %s\n%s", migration.Name, err, statement)
 		}
 	}
 
+	if s.dryRun {
+		return nil
+	}
+
 	err := s.conn.RemoveApplied(migration.Name)
 	if err != nil {
 		return fmt.Errorf("unable to mark migration %s as not applied: %s", migration.Name, err)

service_test.go

@@ -43,7 +43,7 @@ func TestNewService(t *testing.T) {
 	}
 
 	for n, c := range cases {
-		_, err := NewService(c.input)
+		_, err := NewService(c.input, false)
 		if (err != nil) != c.err {
 			t.Error("case", n, "got unexpected error:", err)
 		}