DEV: Move spec/components to spec/lib (#15987)

Lib specs were inexplicably split into two directories (`lib` and `components`)

This moves them all into `lib`.

spec/lib/content_buffer_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+require 'content_buffer'
+
+describe ContentBuffer do
+
+  it "handles deletion across lines properly" do
+    c = ContentBuffer.new("a\nbc\nc")
+    c.apply_transform!(start: { row: 0, col: 0 }, finish: { col: 1, row: 1 }, operation: :delete)
+    expect(c.to_s).to eq("c\nc")
+  end
+  it "handles deletion inside lines properly" do
+    c = ContentBuffer.new("hello world")
+    c.apply_transform!(start: { row: 0, col: 1 }, finish: { col: 4, row: 0 }, operation: :delete)
+    expect(c.to_s).to eq("ho world")
+  end
+
+  it "handles inserts inside lines properly" do
+    c = ContentBuffer.new("hello!")
+    c.apply_transform!(start: { row: 0, col: 5 }, operation: :insert, text: " world")
+    expect(c.to_s).to eq("hello world!")
+  end
+
+  it "handles multiline inserts" do
+    c = ContentBuffer.new("hello!")
+    c.apply_transform!(start: { row: 0, col: 5 }, operation: :insert, text: "\nworld")
+    expect(c.to_s).to eq("hello\nworld!")
+  end
+
+end