Neotest-minitest: Fix SpecReporter Output Parsing

Hey everyone! Have you ever encountered a situation where your tests are passing in the console, but Neotest stubbornly marks them as failures? It can be super frustrating, especially when you're trying to maintain a clean and green test suite. Let's dive into a specific scenario involving neotest-minitest and Minitest::Reporters::SpecReporter that can cause this headache.

The Problem: Red Ticks Despite Passing Tests

Imagine this: You're rocking Neovim, using the awesome neotest-minitest adapter, and you've chosen the stylish Minitest::Reporters::SpecReporter to format your test output. You run your tests, and everything looks good in the terminal – all green, no failures, zero errors. But then you glance at your Neotest UI, and bam! Red ticks everywhere, indicating failures. What gives?

This quirky behavior arises from a mismatch in how neotest-minitest parses test output when you're using SpecReporter. Let's break down the specifics, look at some code, and figure out how to tackle this issue.

Digging into the Details: A Real-World Example

Let's look at a real-world scenario to illustrate the issue. Suppose you have a Minitest setup with SpecReporter enabled. Your test suite includes a simple assertion, like this:

require 'minitest/autorun'
require 'minitest/reporters'
Minitest::Reporters.use! [Minitest::Reporters::SpecReporter.new]

class TestTaped < Minitest::Test
  def test_simple_setting
    assert_equal 42, 42
  end
end

You run this test using Neotest, and the output in your terminal looks something like this:

TestTaped
  test_simple_setting                                           PASS (0.00s)

Finished in 0.00091s
1 tests, 1 assertions, 0 failures, 0 errors, 0 skips

Everything looks perfect! But then, Neotest stubbornly shows a red mark next to the test, signaling a failure. This discrepancy can be incredibly confusing and time-consuming to debug.

Reproducing the Issue: Step-by-Step

To reproduce this issue, follow these simple steps:

1. Set up your reporter: Configure your Minitest environment to use SpecReporter. Add the following lines to your test setup:

   require 'minitest/autorun'
   require 'minitest/reporters'
   Minitest::Reporters.use! [Minitest::Reporters::SpecReporter.new]
   

2. Write a test: Create a basic Minitest test case. For example:

   def test_simple_setting
     assert_equal 42, 42
   end
   

3. Run the test via Neotest: Use Neotest to execute your test suite.

4. Observe the result: Witness the red mark (failed status) in the Neotest UI, even though the test passed in the terminal.

This consistent behavior highlights a clear issue in how Neotest interprets the output from SpecReporter.

Unraveling the Root Cause: Parsing Discrepancies

The heart of the problem lies in the _parse_test_output function within the neotest-minitest adapter. This function is responsible for interpreting the test results from the output stream and translating them into Neotest's UI. It expects test output lines to adhere to a specific format, like this:

TestPre#test_simple_setting = 0.02 s = .

This format is characteristic of the default Minitest reporter. However, SpecReporter has its own distinct style, emitting output that looks more like this:

TestPre
  test_simple_setting                                             PASS (0.02s)

Notice the difference? SpecReporter provides a more human-readable, structured output, but this structure isn't directly compatible with the parsing logic in neotest-minitest. The adapter struggles to extract the test status (pass/fail) from this format, leading to the incorrect