Add ErrTxClosed error.

Commit/Rollback and mutable calls on Tx and Bucket now return ErrTxClosed
if the transaction has already been committed or rolled back. Non-mutable
calls have added an assertion to check if the transaction is closed which
will cause a panic. I don't want to introduce an error return for accessor
methods that are being used improperly so I think the panic is appropriate.

1 files changed, 45 insertions, 0 deletions

diff --git a/tx_test.go b/tx_test.go
index afdbb02..fe33869 100644
--- a/tx_test.go
+++ b/tx_test.go
@@ -13,6 +13,33 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+// Ensure that committing a closed transaction returns an error.
+func TestTxCommitClosed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.RWTx()
+		tx.CreateBucket("foo")
+		assert.NoError(t, tx.Commit())
+		assert.Equal(t, tx.Commit(), ErrTxClosed)
+	})
+}
+
+// Ensure that rolling back a closed transaction returns an error.
+func TestTxRollbackClosed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.RWTx()
+		assert.NoError(t, tx.Rollback())
+		assert.Equal(t, tx.Rollback(), ErrTxClosed)
+	})
+}
+
+// Ensure that committing a read-only transaction returns an error.
+func TestTxCommitReadOnly(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.Tx()
+		assert.Equal(t, tx.Commit(), ErrTxNotWritable)
+	})
+}
+
 // Ensure that the database can retrieve a list of buckets.
 func TestTxBuckets(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
@@ -41,6 +68,15 @@ func TestTxCreateBucketReadOnly(t *testing.T) {
 	})
 }
 
+// Ensure that creating a bucket on a closed transaction returns an error.
+func TestTxCreateBucketClosed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.RWTx()
+		tx.Commit()
+		assert.Equal(t, tx.CreateBucket("foo"), ErrTxClosed)
+	})
+}
+
 // Ensure that a Tx can retrieve a bucket.
 func TestTxBucket(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {
@@ -204,6 +240,15 @@ func TestTxDeleteBucket(t *testing.T) {
 	})
 }
 
+// Ensure that deleting a bucket on a closed transaction returns an error.
+func TestTxDeleteBucketClosed(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		tx, _ := db.RWTx()
+		tx.Commit()
+		assert.Equal(t, tx.DeleteBucket("foo"), ErrTxClosed)
+	})
+}
+
 // Ensure that deleting a bucket with a read-only transaction returns an error.
 func TestTxDeleteBucketReadOnly(t *testing.T) {
 	withOpenDB(func(db *DB, path string) {