1 files changed, 93 insertions, 0 deletions
diff --git a/bug/op_set_title.go b/bug/op_set_title.go
new file mode 100644
index 00000000..e8c5caf8
--- /dev/null
+++ b/bug/op_set_title.go
@@ -0,0 +1,93 @@
+package bug
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/MichaelMure/git-bug/util/text"
+)
+
+// SetTitleOperation will change the title of a bug
+
+var _ Operation = SetTitleOperation{}
+
+type SetTitleOperation struct {
+	*OpBase
+	Title string `json:"title"`
+	Was   string `json:"was"`
+}
+
+func (op SetTitleOperation) base() *OpBase {
+	return op.OpBase
+}
+
+func (op SetTitleOperation) Apply(snapshot Snapshot) Snapshot {
+	snapshot.Title = op.Title
+
+	return snapshot
+}
+
+func (op SetTitleOperation) Validate() error {
+	if err := opBaseValidate(op, SetTitleOp); err != nil {
+		return err
+	}
+
+	if text.Empty(op.Title) {
+		return fmt.Errorf("title is empty")
+	}
+
+	if strings.Contains(op.Title, "\n") {
+		return fmt.Errorf("title should be a single line")
+	}
+
+	if !text.Safe(op.Title) {
+		return fmt.Errorf("title should be fully printable")
+	}
+
+	if strings.Contains(op.Was, "\n") {
+		return fmt.Errorf("previous title should be a single line")
+	}
+
+	if !text.Safe(op.Was) {
+		return fmt.Errorf("previous title should be fully printable")
+	}
+
+	return nil
+}
+
+func NewSetTitleOp(author Person, unixTime int64, title string, was string) SetTitleOperation {
+	return SetTitleOperation{
+		OpBase: newOpBase(SetTitleOp, author, unixTime),
+		Title:  title,
+		Was:    was,
+	}
+}
+
+// Convenience function to apply the operation
+func SetTitle(b Interface, author Person, unixTime int64, title string) error {
+	it := NewOperationIterator(b)
+
+	var lastTitleOp Operation
+	for it.Next() {
+		op := it.Value()
+		if op.base().OperationType == SetTitleOp {
+			lastTitleOp = op
+		}
+	}
+
+	var was string
+	if lastTitleOp != nil {
+		was = lastTitleOp.(SetTitleOperation).Title
+	} else {
+		was = b.FirstOp().(CreateOperation).Title
+	}
+
+	setTitleOp := NewSetTitleOp(author, unixTime, title, was)
+
+	if err := setTitleOp.Validate(); err != nil {
+		return err
+	}
+
+	b.Append(setTitleOp)
+	return nil
+}