Implements range cut in editor

Author: Ciro S. Costa

editor/cut.go

@@ -11,6 +11,12 @@ import (
 // It assumes that the provided `cast` is entirely valid (see
 // `github.com/cirocosta/asciinema-edit/cast#Validate`).
 //
+// If `from == to`:
+//	the exact timestamp is removed.
+//
+// If `from < to`:
+//	all timestamps from `from` to `to` are removed (both included).
+//
 // 1. search a time that is close to `from`; then
 // 2. search a time that is close to `to`; then
 // 3. remove all in between; then
@@ -33,5 +39,34 @@ func Cut(c *cast.Cast, from, to float64) (err error) {
 		return
 	}
 
+	var (
+		fromIdx = -1
+		toIdx   = -1
+	)
+
+	for idx, ev := range c.EventStream {
+		if ev.Time == from {
+			fromIdx = idx
+		}
+
+		if ev.Time == to {
+			toIdx = idx
+		}
+	}
+
+	if fromIdx == -1 {
+		err = errors.Errorf("couldn't find initial frame")
+		return
+	}
+
+	if toIdx == -1 {
+		err = errors.Errorf("couldn't find final frame")
+		return
+	}
+
+	c.EventStream = append(
+		c.EventStream[:fromIdx],
+		c.EventStream[toIdx+1:]...)
+
 	return
 }

editor/cut_test.go

@@ -48,8 +48,9 @@ var _ = Describe("Cut", func() {
 
 	Context("with non-empty event stream", func() {
 		var (
-			err  error
-			data *cast.Cast
+			err                   error
+			data                  *cast.Cast
+			initialNumberOfEvents int
 		)
 
 		BeforeEach(func() {
@@ -61,11 +62,37 @@ var _ = Describe("Cut", func() {
 					event2,
 				},
 			}
+
+			initialNumberOfEvents = len(data.EventStream)
 		})
 
 		It("fails if `from` > `to`", func() {
 			err = editor.Cut(data, 3, 2)
 			Expect(err).ToNot(Succeed())
 		})
+
+		It("cuts single frame if `from` == `to`", func() {
+			err = editor.Cut(data, 1.2, 1.2)
+			Expect(err).To(Succeed())
+
+			Expect(data.EventStream).To(ContainElement(event1))
+			Expect(data.EventStream).ToNot(ContainElement(event1_2))
+			Expect(data.EventStream).To(ContainElement(event1_6))
+			Expect(data.EventStream).To(ContainElement(event2))
+
+			Expect(len(data.EventStream)).To(Equal(initialNumberOfEvents - 1))
+		})
+
+		It("cuts frames in range", func() {
+			err = editor.Cut(data, 1.2, 2)
+			Expect(err).To(Succeed())
+
+			Expect(data.EventStream).To(ContainElement(event1))
+			Expect(data.EventStream).ToNot(ContainElement(event1_2))
+			Expect(data.EventStream).ToNot(ContainElement(event1_6))
+			Expect(data.EventStream).ToNot(ContainElement(event2))
+
+			Expect(len(data.EventStream)).To(Equal(initialNumberOfEvents - 3))
+		})
 	})
 })