Add status command (#120)

Add new command to list applied and pending migrations.

Closes #28
Closes #32
Closes #66
Closes #120

pkg/dbmate/db.go

@@ -35,6 +35,14 @@ type DB struct {
 	WaitTimeout    time.Duration
 }
 
+// migrationFileRegexp pattern for valid migration files
+var migrationFileRegexp = regexp.MustCompile(`^\d.*\.sql$`)
+
+type statusResult struct {
+	filename string
+	applied  bool
+}
+
 // New initializes a new dbmate database
 func New(databaseURL *url.URL) *DB {
 	return &DB{
@@ -253,8 +261,7 @@ func (db *DB) openDatabaseForMigration() (Driver, *sql.DB, error) {
 
 // Migrate migrates database to the latest version
 func (db *DB) Migrate() error {
-	re := regexp.MustCompile(`^\d.*\.sql$`)
-	files, err := findMigrationFiles(db.MigrationsDir, re)
+	files, err := findMigrationFiles(db.MigrationsDir, migrationFileRegexp)
 	if err != nil {
 		return err
 	}
@@ -445,3 +452,66 @@ func (db *DB) Rollback() error {
 
 	return nil
 }
+
+func checkMigrationsStatus(db *DB) ([]statusResult, error) {
+	files, err := findMigrationFiles(db.MigrationsDir, migrationFileRegexp)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(files) == 0 {
+		return nil, fmt.Errorf("no migration files found")
+	}
+
+	drv, sqlDB, err := db.openDatabaseForMigration()
+	if err != nil {
+		return nil, err
+	}
+	defer mustClose(sqlDB)
+
+	applied, err := drv.SelectMigrations(sqlDB, -1)
+	if err != nil {
+		return nil, err
+	}
+
+	var results []statusResult
+
+	for _, filename := range files {
+		ver := migrationVersion(filename)
+		res := statusResult{filename: filename}
+		if ok := applied[ver]; ok {
+			res.applied = true
+		} else {
+			res.applied = false
+		}
+
+		results = append(results, res)
+	}
+
+	return results, nil
+}
+
+// Status shows the status of all migrations
+func (db *DB) Status() error {
+	results, err := checkMigrationsStatus(db)
+	if err != nil {
+		return err
+	}
+
+	var totalApplied int
+
+	for _, res := range results {
+		if res.applied {
+			fmt.Println("[X]", res.filename)
+			totalApplied++
+		} else {
+			fmt.Println("[ ]", res.filename)
+		}
+	}
+
+	fmt.Println()
+	fmt.Printf("Applied: %d\n", totalApplied)
+	fmt.Printf("Pending: %d\n", len(results)-totalApplied)
+
+	return nil
+}

pkg/dbmate/db_test.go

@@ -298,6 +298,9 @@ func testRollbackURL(t *testing.T, u *url.URL) {
 	require.NoError(t, err)
 	require.Equal(t, 1, count)
 
+	err = sqlDB.QueryRow("select count(*) from posts").Scan(&count)
+	require.Nil(t, err)
+
 	// rollback
 	err = db.Rollback()
 	require.NoError(t, err)
@@ -305,9 +308,9 @@ func testRollbackURL(t *testing.T, u *url.URL) {
 	// verify rollback
 	err = sqlDB.QueryRow("select count(*) from schema_migrations").Scan(&count)
 	require.NoError(t, err)
-	require.Equal(t, 0, count)
+	require.Equal(t, 1, count)
 
-	err = sqlDB.QueryRow("select count(*) from users").Scan(&count)
+	err = sqlDB.QueryRow("select count(*) from posts").Scan(&count)
 	require.NotNil(t, err)
 	require.Regexp(t, "(does not exist|doesn't exist|no such table)", err.Error())
 }
@@ -317,3 +320,53 @@ func TestRollback(t *testing.T) {
 		testRollbackURL(t, u)
 	}
 }
+
+func testStatusUrl(t *testing.T, u *url.URL) {
+	db := newTestDB(t, u)
+
+	// drop, recreate, and migrate database
+	err := db.Drop()
+	require.NoError(t, err)
+	err = db.Create()
+	require.NoError(t, err)
+
+	// verify migration
+	sqlDB, err := GetDriverOpen(u)
+	require.NoError(t, err)
+	defer mustClose(sqlDB)
+
+	// two pending
+	results, err := checkMigrationsStatus(db)
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+	require.False(t, results[0].applied)
+	require.False(t, results[1].applied)
+
+	// run migrations
+	err = db.Migrate()
+	require.NoError(t, err)
+
+	// two applied
+	results, err = checkMigrationsStatus(db)
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+	require.True(t, results[0].applied)
+	require.True(t, results[1].applied)
+
+	// rollback last migration
+	err = db.Rollback()
+	require.NoError(t, err)
+
+	// one applied, one pending
+	results, err = checkMigrationsStatus(db)
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+	require.True(t, results[0].applied)
+	require.False(t, results[1].applied)
+}
+
+func TestStatus(t *testing.T) {
+	for _, u := range testURLs(t) {
+		testStatusUrl(t, u)
+	}
+}