finish first MVP with test-runner-detection for Go, Mocha.js, Jest.js and ViTest.js

tests/test_samurai_core_spec.lua

@@ -1,9 +1,17 @@
 local test_samurai = require("test-samurai")
 local core = require("test-samurai.core")
+local util = require("test-samurai.util")
+
+local orig_find_root = util.find_root
+local orig_fs_stat = vim.loop.fs_stat
+local orig_readfile = vim.fn.readfile
 
 describe("test-samurai core", function()
   before_each(function()
     test_samurai.setup()
+    util.find_root = orig_find_root
+    vim.loop.fs_stat = orig_fs_stat
+    vim.fn.readfile = orig_readfile
   end)
 
   it("selects Go runner for _test.go files", function()
@@ -23,4 +31,43 @@ describe("test-samurai core", function()
     assert.is_not_nil(runner)
     assert.equals("js-jest", runner.name)
   end)
+
+  it("prefers mocha runner when mocha is in package.json", function()
+    util.find_root = function(_, _)
+      return "/tmp/mocha_proj"
+    end
+
+    vim.loop.fs_stat = function(path)
+      if path == "/tmp/mocha_proj/package.json" then
+        return { type = "file" }
+      end
+      return nil
+    end
+
+    vim.fn.readfile = function(path)
+      if path == "/tmp/mocha_proj/package.json" then
+        return {
+          "{",
+          '  "devDependencies": { "mocha": "^10.0.0" }',
+          "}",
+        }
+      end
+      return {}
+    end
+
+    test_samurai.setup()
+
+    local bufnr = vim.api.nvim_create_buf(false, true)
+    vim.api.nvim_buf_set_name(bufnr, "/tmp/mocha_proj/foo.test.ts")
+    vim.bo[bufnr].filetype = "typescript"
+
+    local runner = core.get_runner_for_buf(bufnr)
+
+    util.find_root = orig_find_root
+    vim.loop.fs_stat = orig_fs_stat
+    vim.fn.readfile = orig_readfile
+
+    assert.is_not_nil(runner)
+    assert.equals("js-mocha", runner.name)
+  end)
 end)