impdev

1 files changed, 68 insertions, 0 deletions

diff --git a/lib/dispatch/tool/files/read_file.rb b/lib/dispatch/tool/files/read_file.rb
new file mode 100644
index 0000000..c0c5edc
--- /dev/null
+++ b/lib/dispatch/tool/files/read_file.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+module Dispatch
+  module Tool
+    module Files
+      READ_FILE = Dispatch::Tools::Definition.new(
+        name: "read_file",
+        description: "Read the contents of a file. Returns file contents with line numbers.",
+        parameters: {
+          type: "object",
+          properties: {
+            path: {
+              type: "string",
+              description: "Path to the file to read, relative to the worktree root."
+            },
+            start_line: {
+              type: "integer",
+              description: "The line number to start reading from (0-based). Defaults to 0."
+            },
+            end_line: {
+              type: "integer",
+              description: "The inclusive line number to stop reading at (0-based). Use -1 for end of file."
+            }
+          },
+          required: %w[path],
+          additionalProperties: false
+        }
+      ) do |params, context|
+        worktree_path = context[:worktree_path]
+        path = params[:path]
+
+        resolved = begin
+          Sandbox.resolve_path(path, worktree_path:)
+        rescue SandboxError => e
+          next Dispatch::Tools::Result.failure(error: e.message)
+        end
+
+        unless File.exist?(resolved)
+          next Dispatch::Tools::Result.failure(error: "File not found: #{path}")
+        end
+
+        # Binary file detection: check first 8192 bytes for null bytes
+        sample = File.binread(resolved, 8192)
+        if sample.include?("\x00")
+          next Dispatch::Tools::Result.failure(error: "Cannot read binary file: #{path}")
+        end
+
+        lines = File.readlines(resolved)
+
+        start_line = params.fetch(:start_line, 0)
+        end_line = params.fetch(:end_line, -1)
+        end_line = lines.length - 1 if end_line == -1
+
+        selected = lines[start_line..end_line] || []
+
+        # Calculate padding width based on the highest line number
+        width = end_line.to_s.length
+
+        output = selected.each_with_index.map do |line, idx|
+          line_num = start_line + idx
+          "#{line_num.to_s.rjust(width)}: #{line}"
+        end.join
+
+        Dispatch::Tools::Result.success(output:)
+      end
+    end
+  end
+end