fix TSamFailedOnly and the output formatting for the mocha-runner

tests/test_samurai_output_spec.lua

@@ -273,6 +273,67 @@ describe("test-samurai output formatting", function()
     assert.is_false(has_raw_json)
   end)
 
+  it("formats mocha json-stream array output as PASS/FAIL lines", function()
+    test_samurai.setup({
+      runner_modules = {
+        "test-samurai.runners.js-mocha",
+      },
+    })
+
+    local pass_line = vim.json.encode({
+      "pass",
+      {
+        title = "GET: /",
+        fullTitle = "API :: /brands... GET: /",
+      },
+    })
+
+    local orig_jobstart = vim.fn.jobstart
+    vim.fn.jobstart = function(_cmd, opts)
+      if opts and opts.on_stdout then
+        opts.on_stdout(1, { pass_line }, nil)
+      end
+      if opts and opts.on_exit then
+        opts.on_exit(1, 0, nil)
+      end
+      return 1
+    end
+
+    local bufnr = vim.api.nvim_create_buf(false, true)
+    vim.api.nvim_buf_set_name(bufnr, "/tmp/output_mocha_json_stream.test.js")
+    vim.bo[bufnr].filetype = "javascript"
+    vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, {
+      'describe("outer", function() {',
+      '  it("inner 1", function() {',
+      "    -- inside 1",
+      "  })",
+      "})",
+    })
+
+    vim.api.nvim_set_current_buf(bufnr)
+    vim.api.nvim_win_set_cursor(0, { 3, 0 })
+
+    core.run_nearest()
+
+    local out_buf = vim.api.nvim_get_current_buf()
+    local lines = vim.api.nvim_buf_get_lines(out_buf, 0, -1, false)
+
+    vim.fn.jobstart = orig_jobstart
+
+    local has_pass = false
+    local has_raw_json = false
+    for _, line in ipairs(lines) do
+      if line == "[ PASS ] - API :: /brands... GET: /" then
+        has_pass = true
+      elseif line == pass_line then
+        has_raw_json = true
+      end
+    end
+
+    assert.is_true(has_pass)
+    assert.is_false(has_raw_json)
+  end)
+
   it("does not print raw JSON when JSON arrives on stdout and stderr", function()
     test_samurai.setup({
       runner_modules = {
@@ -426,15 +487,19 @@ describe("test-samurai output formatting", function()
     assert.is_true(#job_calls >= 2)
     local failed_cmd = job_calls[2].cmd or {}
     local saw_grep = false
+    local saw_fgrep = false
     local saw_title = false
     for _, arg in ipairs(failed_cmd) do
       if arg == "--grep" then
         saw_grep = true
+      elseif arg == "--fgrep" then
+        saw_fgrep = true
       elseif arg == "outer inner 2" then
         saw_title = true
       end
     end
-    assert.is_true(saw_grep)
+    assert.is_false(saw_grep)
+    assert.is_true(saw_fgrep)
     assert.is_true(saw_title)
   end)