add grep tool formatters

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

@@ -148,6 +148,38 @@ def format_edit
                 "EDIT #{path} (#{count} #{"edit".pluralize(count)})"
               end
 
+              # Formats a grep tool call.
+              #
+              # Input fields:
+              #   :pattern (String)  – regex/text to search for      [required]
+              #   :path    (String)  – file or directory to search   [optional]
+              #   :glob    (String)  – glob filter for matched files [optional]
+              #   :limit   (Integer) – max number of matches         [optional]
+              #
+              # Output: 'GREP "<pattern>" <path> (glob: <glob>, limit: <limit>)' –
+              # <pattern> is truncated to TRUNCATE_LIMIT chars; <path> is shown only
+              # when present. The "glob:" and "limit:" details are each included only
+              # when present and joined with ", " inside a single trailing "(...)".
+              # `path`, `glob` and `limit` are left untruncated as they are usually short and
+              # contain important information that we don't want to truncate.
+              #
+              # Examples:
+              #   GREP "def format" lib (glob: *.rb, limit: 50)
+              #   GREP "TODO" (limit: 50)
+              #   GREP "TODO"
+              #
+              #: () -> String
+              def format_grep
+                pattern, path, glob, limit = arguments.values_at(:pattern, :path, :glob, :limit)
+                base = "GREP \"#{truncate(pattern)}\""
+                base = "#{base} #{path}" if path.present?
+                details = [
+                  ("glob: #{glob}" if glob.present?),
+                  ("limit: #{limit}" if limit.present?),
+                ].compact
+                details.any? ? "#{base} (#{details.join(", ")})" : base
+              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

@@ -128,6 +128,30 @@ def format_edit
                 ok_line(@input[:path])
               end
 
+              # Formats a grep tool result.
+              #
+              # Content: matching lines, and possibly informational notes, one per
+              # line.
+              #
+              # Output: "GREP OK <n> <match|matches>[ · NOTE <notes>]" – <n> counts
+              # lines that look like matches (a leading path or line-number prefix);
+              # any remaining lines are joined into a truncated NOTE, shown only when
+              # there are both matches and notes.
+              #
+              # Examples:
+              #   GREP OK 3 matches
+              #   GREP OK 1 match
+              #   GREP OK 0 matches
+              #
+              #: () -> String
+              def format_grep
+                lines = content.to_s.lines.map(&:strip).reject(&:empty?)
+                matches, notes = lines.partition { |line| line.match?(%r{\A\S+/}) || line.match?(/\A(?:\S+:)?\d+:/) }
+                count = matches.length
+                note = "NOTE #{truncate(notes.join(" "))}" if matches.any? && notes.any?
+                ok_line("#{count} #{"match".pluralize(count)}", note)
+              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

@@ -124,6 +124,51 @@ class ToolCallMessageTest < ActiveSupport::TestCase
           assert_equal "EDIT lib/roast.rb (0 edits)", msg.format
         end
 
+        test "format renders GREP with the pattern, path, and glob" do
+          msg = ToolCallMessage.new(
+            id: "1",
+            name: "grep",
+            arguments: { pattern: "def format", path: "lib", glob: "*.rb" },
+          )
+          assert_equal 'GREP "def format" lib (glob: *.rb)', msg.format
+        end
+
+        test "format renders GREP with the pattern and path but no glob" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "TODO", path: "lib/roast" })
+          assert_equal 'GREP "TODO" lib/roast', msg.format
+        end
+
+        test "format renders GREP with the pattern and glob but no path" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "TODO", glob: "*.rb" })
+          assert_equal 'GREP "TODO" (glob: *.rb)', msg.format
+        end
+
+        test "format renders GREP with only the pattern" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "TODO" })
+          assert_equal 'GREP "TODO"', msg.format
+        end
+
+        test "format renders GREP with the glob and limit joined in one parenthetical" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "TODO", path: "lib", glob: "*.rb", limit: 50 })
+          assert_equal 'GREP "TODO" lib (glob: *.rb, limit: 50)', msg.format
+        end
+
+        test "format renders GREP with the limit but no glob" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "TODO", limit: 50 })
+          assert_equal 'GREP "TODO" (limit: 50)', msg.format
+        end
+
+        test "format truncates a long grep pattern" do
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: "x" * 100 })
+          assert_equal "GREP \"#{"x" * (ToolCallMessage::TRUNCATE_LIMIT - 3)}...\"", msg.format
+        end
+
+        test "format truncates the grep pattern but not the path" do
+          long = "x" * 100
+          msg = ToolCallMessage.new(id: "1", name: "grep", arguments: { pattern: long, path: long })
+          assert_equal "GREP \"#{"x" * (ToolCallMessage::TRUNCATE_LIMIT - 3)}...\" #{long}", 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

@@ -126,6 +126,50 @@ def setup
           assert_equal "EDIT OK", msg.format(@context)
         end
 
+        test "format summarizes grep output with a match count" do
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "grep",
+            content: "lib/roast.rb:1:class Roast\nlib/roast/version.rb:3:VERSION = \"1.0\"",
+            is_error: false,
+          )
+
+          assert_equal "GREP OK 2 matches", msg.format(@context)
+        end
+
+        test "format pluralizes a single grep match" do
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "grep",
+            content: "lib/roast.rb:1:class Roast",
+            is_error: false,
+          )
+
+          assert_equal "GREP OK 1 match", msg.format(@context)
+        end
+
+        test "format reports zero grep matches when there is no output" do
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "grep",
+            content: nil,
+            is_error: false,
+          )
+
+          assert_equal "GREP OK 0 matches", msg.format(@context)
+        end
+
+        test "format appends a NOTE when grep output includes non-match lines" do
+          msg = ToolResultMessage.new(
+            tool_call_id: "1",
+            tool_name: "grep",
+            content: "lib/roast.rb:1:class Roast\nresults truncated",
+            is_error: false,
+          )
+
+          assert_equal "GREP OK 1 match · NOTE results truncated", msg.format(@context)
+        end
+
         test "format renders NAME ERROR with the message for an error result" do
           msg = ToolResultMessage.new(
             tool_call_id: "1",