Add grep to get_logs

Author: josevalim

lib/tidewave/tools/get_logs.rb

@@ -10,13 +10,20 @@ class Tidewave::Tools::GetLogs < Tidewave::Tools::Base
 
   arguments do
     required(:tail).filled(:integer).description("The number of log entries to return from the end of the log")
+    optional(:grep).filled(:string).description("Filter logs with the given regular expression (case insensitive). E.g. \"error\" when you want to capture errors in particular")
   end
 
-  def call(tail:)
+  def call(tail:, grep: nil)
     log_file = Rails.root.join("log", "#{Rails.env}.log")
     return "Log file not found" unless File.exist?(log_file)
 
-    logs = File.readlines(log_file).last(tail)
-    logs.join
+    logs = File.readlines(log_file)
+
+    if grep
+      regex = Regexp.new(grep, Regexp::IGNORECASE)
+      logs = logs.select { |line| line.match?(regex) }
+    end
+
+    logs.last(tail).join
   end
 end

spec/tools/get_logs_spec.rb

@@ -9,25 +9,65 @@
     end
   end
 
-  describe ".description" do
-    it "returns the correct description" do
-      expect(described_class.description).to eq(
-        <<~DESCRIPTION
-          Returns all log output, excluding logs that were caused by other tool calls.
-
-          Use this tool to check for request logs or potentially logged errors.
-        DESCRIPTION
-      )
-    end
-  end
-
   describe "#call" do
     let(:log_file_path) { "spec/fixtures/fake_development_log.log" }
     let(:log_file_content) { File.read(log_file_path) }
 
-    it "returns the correct logs" do
+    before do
       allow(Rails).to receive_message_chain(:root, :join).and_return(Pathname.new(log_file_path))
-      expect(described_class.new.call(tail: 10)).to eq(log_file_content.lines.last(10).join)
+    end
+
+    context "without grep filter" do
+      it "returns the correct logs" do
+        expect(described_class.new.call(tail: 10)).to eq(log_file_content.lines.last(10).join)
+      end
+
+      it "returns all lines when tail is larger than file" do
+        total_lines = log_file_content.lines.count
+        expect(described_class.new.call(tail: total_lines + 10)).to eq(log_file_content)
+      end
+    end
+
+    context "with grep filter" do
+      it "filters logs with the given regular expression" do
+        result = described_class.new.call(tail: 100, grep: "Never gonna")
+        lines = result.lines
+
+        expect(lines.all? { |line| line.match?(/Never gonna/) }).to be true
+        expect(lines.size).to be > 0
+      end
+
+      it "respects tail limit after filtering" do
+        result = described_class.new.call(tail: 3, grep: "Never gonna")
+        lines = result.lines
+        expect(lines.size).to eq(3)
+      end
+
+      it "works with case-insensitive regex" do
+        result = described_class.new.call(tail: 100, grep: "NEVER GONNA")
+        lines = result.lines
+
+        expect(lines.all? { |line| line.match?(/Never gonna/i) }).to be true
+        expect(lines.size).to be > 0
+      end
+
+      it "works with complex regex patterns" do
+        result = described_class.new.call(tail: 100, grep: "never gonna (give|let)")
+        lines = result.lines
+
+        expect(lines.all? { |line| line.match?(/Never gonna (give|let)/i) }).to be true
+        expect(lines.size).to be > 0
+      end
+    end
+
+    context "when log file doesn't exist" do
+      before do
+        allow(Rails).to receive_message_chain(:root, :join).and_return(Pathname.new("nonexistent.log"))
+      end
+
+      it "returns appropriate message" do
+        expect(described_class.new.call(tail: 10)).to eq("Log file not found")
+      end
     end
   end
 end