fix(testables): support --nocapture when using nextest (#877)

Author: mrcjkb

.luacheckrc

@@ -1,10 +1,12 @@
 ignore = {
-  "631",    -- max_line_length
-  "122",    -- read-only field of global variable
+  "631", -- max_line_length
+  "122", -- read-only field of global variable
 }
 read_globals = {
   "vim",
   "describe",
   "it",
-  "assert"
+  "assert",
+  "setup",
+  "teardown",
 }

lua/rustaceanvim/overrides.lua

@@ -73,7 +73,8 @@ function M.maybe_nextest_transform(args)
   table.insert(nextest_args, '--config-file')
   table.insert(nextest_args, require('rustaceanvim.cache').nextest_config_path())
 
-  -- tranform `-- test_something --exact` into `-E 'test("test_something")'`
+  -- tranform:
+  -- - `-- --exact foo` -> `-- foo`
   for i = 1, #executable_args do
     if executable_args[i] == '--exact' then
       local test_name = executable_args[i - 1]
@@ -84,20 +85,34 @@ function M.maybe_nextest_transform(args)
     end
   end
 
+  -- these flags are unsupported by cargo-nextest and should be removed.
+  ---@type table<string, true>
   local nextest_unsupported_flags = {
-    '--show-output',
+    ['--show-output'] = true,
+  }
+  -- cargo test passes these flags to the test executable,
+  -- while cargo-nextest expects them to be passed to the test runner executable.
+  ---@type table<string, true>
+  local move_to_nextest_args_flags = {
+    ['--nocapture'] = true,
   }
   local indexes_to_remove_reverse_order = {}
   for i, arg in ipairs(executable_args) do
-    if vim.list_contains(nextest_unsupported_flags, arg) then
+    if nextest_unsupported_flags[arg] then
+      table.insert(indexes_to_remove_reverse_order, 1, i)
+    end
+    if move_to_nextest_args_flags[arg] then
       table.insert(indexes_to_remove_reverse_order, 1, i)
+      table.insert(nextest_args, arg)
     end
   end
   for _, i in pairs(indexes_to_remove_reverse_order) do
     table.remove(executable_args, i)
   end
 
-  table.insert(nextest_args, '--')
+  if #executable_args > 0 then
+    table.insert(nextest_args, '--')
+  end
   for _, v in ipairs(executable_args) do
     table.insert(nextest_args, v)
   end

spec/nextest_spec.lua

@@ -0,0 +1,96 @@
+local overrides = require('rustaceanvim.overrides')
+local maybe_nextest_transform = overrides.maybe_nextest_transform
+
+local orig_vim_fn_executable = vim.fn.executable
+
+setup(function()
+  ---@diagnostic disable-next-line: duplicate-set-field
+  vim.fn.executable = function(expr)
+    if expr == 'cargo-nextest' then
+      return 1
+    end
+    return orig_vim_fn_executable(expr)
+  end
+end)
+
+teardown(function()
+  vim.fn.executable = orig_vim_fn_executable
+end)
+
+describe('nextest', function()
+  describe('`cargo test <target>` -> `cargo nextest run <target>`', function()
+    local args = {
+      'test',
+      'tests::my_test_target',
+    }
+    local transformed_args = maybe_nextest_transform(args)
+    assert.are.same({
+      'nextest',
+      'run',
+      'tests::my_test_target',
+    }, { unpack(transformed_args, 1, 3) })
+  end)
+  describe('`-- --exact <target>` -> `-- <target>`', function()
+    local args = {
+      'test',
+      'tests::my_test_target',
+      '--',
+      'foo',
+      '--exact',
+    }
+    local transformed_args = maybe_nextest_transform(args)
+    assert.False(vim.tbl_contains(transformed_args, '--exact'))
+    assert.True(vim.tbl_contains(transformed_args, 'foo'))
+  end)
+  describe('removes unsupported `--show-output`', function()
+    local args = {
+      'test',
+      'tests::my_test_target',
+      '--',
+      '--show-output',
+    }
+    local transformed_args = maybe_nextest_transform(args)
+    assert.False(vim.tbl_contains(transformed_args, '--show-output'))
+  end)
+  describe('`-- foo --nocapture` -> `--nocapture -- foo`', function()
+    local args = {
+      'test',
+      'tests::my_test_target',
+      '--',
+      'foo',
+      '--nocapture',
+    }
+    local transformed_args = maybe_nextest_transform(args)
+    assert.are.same({
+      'nextest',
+      'run',
+      'tests::my_test_target',
+      '--profile',
+      'rustaceanvim',
+      '--config-file',
+      require('rustaceanvim.cache').nextest_config_path(),
+      '--nocapture',
+      '--',
+      'foo',
+    }, transformed_args)
+  end)
+  describe('`-- --nocapture` -> `--nocapture`', function()
+    local args = {
+      'test',
+      'tests::my_test_target',
+      '--',
+      '--nocapture',
+    }
+    local transformed_args = maybe_nextest_transform(args)
+    assert.are.same({
+      'nextest',
+      'run',
+      'tests::my_test_target',
+      '--profile',
+      'rustaceanvim',
+      '--config-file',
+      require('rustaceanvim.cache').nextest_config_path(),
+      '--nocapture',
+    }, transformed_args)
+  end)
+end)