1 files changed, 108 insertions, 0 deletions
diff --git a/spec/dispatch/tool/files/read_file_spec.rb b/spec/dispatch/tool/files/read_file_spec.rb
new file mode 100644
index 0000000..01b7828
--- /dev/null
+++ b/spec/dispatch/tool/files/read_file_spec.rb
@@ -0,0 +1,108 @@
+# frozen_string_literal: true
+
+RSpec.describe "read_file tool" do
+  let(:worktree_path) { Dir.mktmpdir("read-file-test") }
+  let(:context) { { worktree_path: } }
+  let(:registry) { Dispatch::Tools::Registry.new }
+
+  before { Dispatch::Tool::Files.register(registry) }
+
+  after { FileUtils.remove_entry(worktree_path) }
+
+  subject(:tool) { registry.get("read_file") }
+
+  describe "reading a full file" do
+    it "returns file contents with line numbers" do
+      File.write(File.join(worktree_path, "hello.txt"), "line one\nline two\nline three\n")
+
+      result = tool.call({ "path" => "hello.txt" }, context:)
+
+      expect(result.success?).to be true
+      expect(result.output).to include("line one")
+      expect(result.output).to include("line two")
+      expect(result.output).to include("line three")
+    end
+
+    it "prefixes each line with its line number" do
+      File.write(File.join(worktree_path, "numbered.txt"), "alpha\nbeta\ngamma\n")
+
+      result = tool.call({ "path" => "numbered.txt" }, context:)
+
+      expect(result.success?).to be true
+      lines = result.output.split("\n")
+      expect(lines[0]).to match(/\A\s*0.*alpha/)
+      expect(lines[1]).to match(/\A\s*1.*beta/)
+      expect(lines[2]).to match(/\A\s*2.*gamma/)
+    end
+  end
+
+  describe "reading a line range" do
+    before do
+      content = (0..9).map { |i| "line #{i}" }.join("\n") + "\n"
+      File.write(File.join(worktree_path, "lines.txt"), content)
+    end
+
+    it "returns only the specified line range (0-based)" do
+      result = tool.call({ "path" => "lines.txt", "start_line" => 2, "end_line" => 4 }, context:)
+
+      expect(result.success?).to be true
+      expect(result.output).to include("line 2")
+      expect(result.output).to include("line 3")
+      expect(result.output).to include("line 4")
+      expect(result.output).not_to include("line 1")
+      expect(result.output).not_to include("line 5")
+    end
+
+    it "reads from start_line to end of file when end_line is -1" do
+      result = tool.call({ "path" => "lines.txt", "start_line" => 8, "end_line" => -1 }, context:)
+
+      expect(result.success?).to be true
+      expect(result.output).to include("line 8")
+      expect(result.output).to include("line 9")
+      expect(result.output).not_to include("line 7")
+    end
+
+    it "reads from the beginning when only end_line is specified" do
+      result = tool.call({ "path" => "lines.txt", "end_line" => 1 }, context:)
+
+      expect(result.success?).to be true
+      expect(result.output).to include("line 0")
+      expect(result.output).to include("line 1")
+      expect(result.output).not_to include("line 2")
+    end
+  end
+
+  describe "error cases" do
+    it "returns failure when the file does not exist" do
+      result = tool.call({ "path" => "nonexistent.txt" }, context:)
+
+      expect(result.failure?).to be true
+      expect(result.error).to match(/not found|does not exist/i)
+    end
+
+    it "returns failure when the path escapes the sandbox" do
+      result = tool.call({ "path" => "../../../etc/passwd" }, context:)
+
+      expect(result.failure?).to be true
+      expect(result.error).to match(/sandbox|outside/i)
+    end
+
+    it "returns failure for a binary file" do
+      binary_path = File.join(worktree_path, "binary.bin")
+      File.write(binary_path, "Hello\x00World\x00Binary\x00Content")
+
+      result = tool.call({ "path" => "binary.bin" }, context:)
+
+      expect(result.failure?).to be true
+      expect(result.error).to match(/binary/i)
+    end
+  end
+
+  describe "parameter validation" do
+    it "requires the path parameter" do
+      result = tool.call({}, context:)
+
+      expect(result.failure?).to be true
+    end
+  end
+end