1 files changed, 114 insertions, 0 deletions
diff --git a/spec/syntax_suggest/unit/scan_history_spec.rb b/spec/syntax_suggest/unit/scan_history_spec.rb
new file mode 100644
index 0000000000..d8b0a54ba6
--- /dev/null
+++ b/spec/syntax_suggest/unit/scan_history_spec.rb
@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require_relative "../spec_helper"
+
+module SyntaxSuggest
+  RSpec.describe ScanHistory do
+    it "retains commits" do
+      source = <<~EOM
+        class OH         #  0
+          def lol        #  1
+            print 'lol   #  2
+          end            #  3
+
+          def hello      #  5
+            it "foo" do  #  6
+          end            #  7
+
+          def yolo       #  8
+            print 'haha' #  9
+          end            # 10
+        end
+      EOM
+
+      code_lines = CleanDocument.new(source: source).call.lines
+      block = CodeBlock.new(lines: code_lines[6])
+
+      scanner = ScanHistory.new(code_lines: code_lines, block: block)
+      scanner.scan(up: ->(_, _, _) { true }, down: ->(_, _, _) { true })
+
+      expect(scanner.changed?).to be_truthy
+      scanner.commit_if_changed
+      expect(scanner.changed?).to be_falsey
+
+      expect(scanner.lines).to eq(code_lines)
+
+      scanner.stash_changes # Assert does nothing if changes are already committed
+      expect(scanner.lines).to eq(code_lines)
+
+      scanner.revert_last_commit
+
+      expect(scanner.lines.join).to eq(code_lines[6].to_s)
+    end
+
+    it "is stashable" do
+      source = <<~EOM
+        class OH         #  0
+          def lol        #  1
+            print 'lol   #  2
+          end            #  3
+
+          def hello      #  5
+            it "foo" do  #  6
+          end            #  7
+
+          def yolo       #  8
+            print 'haha' #  9
+          end            # 10
+        end
+      EOM
+
+      code_lines = CleanDocument.new(source: source).call.lines
+      block = CodeBlock.new(lines: code_lines[6])
+
+      scanner = ScanHistory.new(code_lines: code_lines, block: block)
+      scanner.scan(up: ->(_, _, _) { true }, down: ->(_, _, _) { true })
+
+      expect(scanner.lines).to eq(code_lines)
+      expect(scanner.changed?).to be_truthy
+      expect(scanner.next_up).to be_falsey
+      expect(scanner.next_down).to be_falsey
+
+      scanner.stash_changes
+
+      expect(scanner.changed?).to be_falsey
+
+      expect(scanner.next_up).to eq(code_lines[5])
+      expect(scanner.lines.join).to eq(code_lines[6].to_s)
+      expect(scanner.next_down).to eq(code_lines[7])
+    end
+
+    it "doesnt change if you dont't change it" do
+      source = <<~EOM
+        class OH         #  0
+          def lol        #  1
+            print 'lol   #  2
+          end            #  3
+
+          def hello      #  5
+            it "foo" do  #  6
+          end            #  7
+
+          def yolo       #  8
+            print 'haha' #  9
+          end            # 10
+        end
+      EOM
+
+      code_lines = CleanDocument.new(source: source).call.lines
+      block = CodeBlock.new(lines: code_lines[6])
+
+      scanner = ScanHistory.new(code_lines: code_lines, block: block)
+
+      lines = scanner.lines
+      expect(scanner.changed?).to be_falsey
+      expect(scanner.next_up).to eq(code_lines[5])
+      expect(scanner.next_down).to eq(code_lines[7])
+
+      expect(scanner.stash_changes.lines).to eq(lines)
+      expect(scanner.revert_last_commit.lines).to eq(lines)
+
+      expect(scanner.scan(up: ->(_, _, _) { false }, down: ->(_, _, _) { false }).lines).to eq(lines)
+    end
+  end
+end