Improve pipe completion if the user adds an accidental extra pipe

If we autocomplete pipes and the user still accidentally adds the second
one, we currently end up autocompleting in both cases and end up with 4
pipes.

This commits makes it so that if the user inserted a second pipe after
the autocomplete, we remove the pipe we added automatically and avoid
adding yet another one, resulting in two pipes.

Author: vinistock

lib/ruby_lsp/requests/on_type_formatting.rb

@@ -62,9 +62,34 @@ def run
 
       sig { void }
       def handle_pipe
-        return unless /((?<=do)|(?<={))\s+\|/.match?(@previous_line)
+        current_line = @lines[@position[:line]]
+        return unless /((?<=do)|(?<={))\s+\|/.match?(current_line)
+
+        line = T.must(current_line)
+
+        # If the current character is a pipe and both previous ones are pipes too, then we autocompleted a pipe and the
+        # user inserted a third one. In this case, we need to avoid adding a fourth and remove the previous one
+        if line[@position[:character] - 2] == "|" &&
+            line[@position[:character] - 1] == "|" &&
+            line[@position[:character]] == "|"
+
+          @edits << Interface::TextEdit.new(
+            range: Interface::Range.new(
+              start: Interface::Position.new(
+                line: @position[:line],
+                character: @position[:character],
+              ),
+              end: Interface::Position.new(
+                line: @position[:line],
+                character: @position[:character] + 1,
+              ),
+            ),
+            new_text: "",
+          )
+        else
+          add_edit_with_text("|")
+        end
 
-        add_edit_with_text("|")
         move_cursor_to(@position[:line], @position[:character])
       end
 

test/requests/on_type_formatting_test.rb

@@ -68,14 +68,14 @@ def test_adding_missing_pipe
     )
     document.parse
 
-    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 11 }, "|").run
+    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 12 }, "|").run
     expected_edits = [
       {
-        range: { start: { line: 0, character: 11 }, end: { line: 0, character: 11 } },
+        range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } },
         newText: "|",
       },
       {
-        range: { start: { line: 0, character: 11 }, end: { line: 0, character: 11 } },
+        range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } },
         newText: "$0",
       },
     ]
@@ -94,10 +94,66 @@ def test_pipe_is_not_added_in_regular_or_pipe
     )
     document.parse
 
-    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 11 }, "|").run
+    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 2 }, "|").run
     assert_empty(T.must(edits))
   end
 
+  def test_pipe_is_removed_if_user_adds_manually_after_completion
+    document = RubyLsp::Document.new(source: +"", version: 1, uri: "file:///fake.rb")
+
+    document.push_edits(
+      [{
+        range: { start: { line: 0, character: 0 }, end: { line: 0, character: 0 } },
+        text: "[].each do |",
+      }],
+      version: 2,
+    )
+    document.parse
+
+    document.push_edits(
+      [{
+        range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } },
+        text: "|",
+      }],
+      version: 3,
+    )
+    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 12 }, "|").run
+    expected_edits = [
+      {
+        range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } },
+        newText: "|",
+      },
+      {
+        range: { start: { line: 0, character: 12 }, end: { line: 0, character: 12 } },
+        newText: "$0",
+      },
+    ]
+    assert_equal(expected_edits.to_json, T.must(edits).to_json)
+    assert_equal("[].each do ||", document.source)
+
+    # Push the third pipe manually after the completion happened
+    document.push_edits(
+      [{
+        range: { start: { line: 0, character: 13 }, end: { line: 0, character: 13 } },
+        text: "|",
+      }],
+      version: 3,
+    )
+
+    edits = RubyLsp::Requests::OnTypeFormatting.new(document, { line: 0, character: 13 }, "|").run
+    expected_edits = [
+      {
+        range: { start: { line: 0, character: 13 }, end: { line: 0, character: 14 } },
+        newText: "",
+      },
+      {
+        range: { start: { line: 0, character: 13 }, end: { line: 0, character: 13 } },
+        newText: "$0",
+      },
+    ]
+    assert_equal(expected_edits.to_json, T.must(edits).to_json)
+  end
+
   def test_comment_continuation
     document = RubyLsp::Document.new(source: +"", version: 1, uri: "file:///fake.rb")