add edit tool formatters

lib/roast/cogs/agent/providers/pi/messages/tool_call_message.rb

@@ -127,6 +127,27 @@ def format_write
                 "#{label} \"#{preview}\" (+#{count} #{"line".pluralize(count)})"
               end
 
+              # Formats an edit tool call.
+              #
+              # Input fields:
+              #   :path  (String) – file to edit                          [required]
+              #   :edits (Array)  – edit blocks, each {oldText, newText}   [required]
+              #
+              # Output: "EDIT <path> (<n> <edit|edits>)" – <n> is the number of edit
+              # blocks applied in the call. The count is always shown.
+              #
+              # Examples:
+              #   EDIT lib/roast.rb (1 edit)
+              #   EDIT config/app.yml (3 edits)
+              #
+              #: () -> String
+              def format_edit
+                path = arguments[:path]
+                edits = arguments[:edits] || []
+                count = edits.length
+                "EDIT #{path} (#{count} #{"edit".pluralize(count)})"
+              end
+
               # Formats a tool call for which Roast has no dedicated formatter.
               #
               # Output: "<NAME> <key>: <value>, ..." – the upcased tool name, then each

lib/roast/cogs/agent/providers/pi/messages/tool_result_message.rb

@@ -112,6 +112,22 @@ def format_write
                 ok_line(@input[:path])
               end
 
+              # Formats an edit tool result.
+              #
+              # Input: :path – the path that was edited, from the originating call.
+              #
+              # Output: "EDIT OK <path>" – the file path, omitted when the call
+              # had none.
+              #
+              # Examples:
+              #   EDIT OK lib/roast/version.rb
+              #   EDIT OK
+              #
+              #: () -> String
+              def format_edit
+                ok_line(@input[:path])
+              end
+
               # Formats a result for which Roast has no dedicated formatter.
               #
               # Content: the tool's output text.

test/roast/cogs/agent/providers/pi/messages/tool_call_message_test.rb

@@ -98,6 +98,32 @@ class ToolCallMessageTest < ActiveSupport::TestCase
           assert_equal "WRITE", msg.format
         end
 
+        test "format renders EDIT with the path and edit count" do
+          msg = ToolCallMessage.new(
+            id: "1",
+            name: "edit",
+            arguments: {
+              path: "lib/roast.rb",
+              edits: [{ oldText: "a", newText: "b" }, { oldText: "c", newText: "d" }],
+            },
+          )
+          assert_equal "EDIT lib/roast.rb (2 edits)", msg.format
+        end
+
+        test "format renders a singular edit count for a single edit" do
+          msg = ToolCallMessage.new(
+            id: "1",
+            name: "edit",
+            arguments: { path: "config/app.yml", edits: [{ oldText: "a", newText: "b" }] },
+          )
+          assert_equal "EDIT config/app.yml (1 edit)", msg.format
+        end
+
+        test "format renders zero edits when the edits array is missing" do
+          msg = ToolCallMessage.new(id: "1", name: "edit", arguments: { path: "lib/roast.rb" })
+          assert_equal "EDIT lib/roast.rb (0 edits)", msg.format
+        end
+
         test "format renders an unhandled tool as NAME key: value, ..." do
           msg = ToolCallMessage.new(
             id: "1",

test/roast/cogs/agent/providers/pi/messages/tool_result_message_test.rb

@@ -101,6 +101,31 @@ def setup
           assert_equal "WRITE OK", msg.format(@context)
         end
 
+        test "format renders EDIT OK with the path from the originating call" do
+          @context.add_tool_call(
+            ToolCallMessage.new(id: "1", name: "edit", arguments: { path: "lib/roast/version.rb" }),
+          )
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "edit",
+            content: "The file has been updated successfully",
+            is_error: false,
+          )
+
+          assert_equal "EDIT OK lib/roast/version.rb", msg.format(@context)
+        end
+
+        test "format renders a bare EDIT OK when the path is unavailable" do
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "edit",
+            content: "The file has been updated successfully",
+            is_error: false,
+          )
+
+          assert_equal "EDIT OK", msg.format(@context)
+        end
+
         test "format renders NAME ERROR with the message for an error result" do
           msg = ToolResultMessage.new(
             tool_call_id: "1",