refactor!: extract mason-lspconfig to separate plugin (#109)

The rationale behind this is to make boundaries clearer as mason.nvim
has no direct relation with lspconfig per se.

Also, hopefully, by having it as a separate package like this would
encourage more people to write similar extensions (think mason-dap and
mason-null-ls). Ideally such extensions wouldn't be required at all, but
there are definitely gaps to fill as of today.

From now on you'll need to add `williamboman/mason-lspconfig.nvim` as
a plugin if you want to use the `mason-lspconfig` extension:

```lua
use {
    { "williamboman/mason.nvim", branch = "alpha" },
    "williamboman/mason-lspconfig.nvim",
    "neovim/nvim-lspconfig",
}
```

```lua
Plug "williamboman/mason.nvim", { 'branch': 'alpha' }
Plug "williamboman/mason-lspconfig.nvim"
Plug "neovim/nvim-lspconfig"
```

3 files changed, 0 insertions, 225 deletions

diff --git a/tests/mason-lspconfig/api/command_spec.lua b/tests/mason-lspconfig/api/command_spec.lua
deleted file mode 100644
index 0551c777..00000000
--- a/tests/mason-lspconfig/api/command_spec.lua
+++ /dev/null
@@ -1,71 +0,0 @@
-local spy = require "luassert.spy"
-local stub = require "luassert.stub"
-local match = require "luassert.match"
-
-local server_mappings = require "mason-lspconfig.mappings.server"
-local filetype_mappings = require "mason-lspconfig.mappings.filetype"
-local api = require "mason-lspconfig.api.command"
-local registry = require "mason-registry"
-local Pkg = require "mason-core.package"
-
-describe(":LspInstall", function()
-    server_mappings.lspconfig_to_package["dummylsp"] = "dummy"
-    server_mappings.package_to_lspconfig["dummy"] = "dummylsp"
-    filetype_mappings.dummylang = { "dummylsp" }
-
-    it("should install the provided servers", function()
-        local dummy = registry.get_package "dummy"
-        spy.on(Pkg, "install")
-        api.LspInstall { "dummylsp@1.0.0" }
-        assert.spy(Pkg.install).was_called(1)
-        assert.spy(Pkg.install).was_called_with(match.ref(dummy), {
-            version = "1.0.0",
-        })
-    end)
-
-    it(
-        "should prompt user for server to install based on filetype",
-        async_test(function()
-            local dummy = registry.get_package "dummy"
-            spy.on(Pkg, "install")
-            stub(vim.ui, "select")
-            vim.ui.select.invokes(function(items, opts, callback)
-                callback "dummylsp"
-            end)
-            vim.cmd [[new | setf dummylang]]
-            api.LspInstall {}
-            assert.spy(Pkg.install).was_called(1)
-            assert.spy(Pkg.install).was_called_with(match.ref(dummy), {
-                version = nil,
-            })
-            assert.spy(vim.ui.select).was_called(1)
-            assert.spy(vim.ui.select).was_called_with({ "dummylsp" }, match.is_table(), match.is_function())
-        end)
-    )
-
-    it(
-        "should not prompt user for server to install if no filetype match exists",
-        async_test(function()
-            spy.on(Pkg, "install")
-            stub(vim.ui, "select")
-            vim.cmd [[new | setf nolsplang]]
-            api.LspInstall {}
-            assert.spy(Pkg.install).was_called(0)
-            assert.spy(vim.ui.select).was_called(0)
-        end)
-    )
-end)
-
-describe(":LspUninstall", function()
-    server_mappings.lspconfig_to_package["dummylsp"] = "dummy"
-    server_mappings.package_to_lspconfig["dummy"] = "dummylsp"
-    filetype_mappings.dummylang = { "dummylsp" }
-
-    it("should uninstall the provided servers", function()
-        local dummy = registry.get_package "dummy"
-        spy.on(Pkg, "uninstall")
-        api.LspUninstall { "dummylsp" }
-        assert.spy(Pkg.uninstall).was_called(1)
-        assert.spy(Pkg.uninstall).was_called_with(match.ref(dummy))
-    end)
-end)
diff --git a/tests/mason-lspconfig/setup_spec.lua b/tests/mason-lspconfig/setup_spec.lua
deleted file mode 100644
index 64067b1c..00000000
--- a/tests/mason-lspconfig/setup_spec.lua
+++ /dev/null
@@ -1,93 +0,0 @@
-local match = require "luassert.match"
-local stub = require "luassert.stub"
-local spy = require "luassert.spy"
-
-local Pkg = require "mason-core.package"
-local mason_lspconfig = require "mason-lspconfig"
-local server_mappings = require "mason-lspconfig.mappings.server"
-local registry = require "mason-registry"
-local filetype_mappings = require "mason-lspconfig.mappings.filetype"
-
-describe("mason-lspconfig setup", function()
-    server_mappings.lspconfig_to_package["dummylsp"] = "dummy"
-    server_mappings.package_to_lspconfig["dummy"] = "dummylsp"
-    filetype_mappings.dummylang = { "dummylsp" }
-
-    it("should set up user commands", function()
-        mason_lspconfig.setup()
-        local user_commands = vim.api.nvim_get_commands {}
-
-        assert.is_true(match.tbl_containing {
-            bang = false,
-            bar = false,
-            nargs = "*",
-            complete = "custom",
-            definition = "Install one or more LSP servers.",
-        }(user_commands["LspInstall"]))
-
-        assert.is_true(match.tbl_containing {
-            bang = false,
-            bar = false,
-            definition = "Uninstall one or more LSP servers.",
-            nargs = "+",
-            complete = "custom",
-        }(user_commands["LspUninstall"]))
-    end)
-
-    it("should install servers listed in ensure_installed", function()
-        local dummy = registry.get_package "dummy"
-        spy.on(Pkg, "install")
-        stub(Pkg, "is_installed")
-        Pkg.is_installed.returns(false)
-        mason_lspconfig.setup { ensure_installed = { "dummylsp@1.0.0" } }
-        assert.spy(Pkg.install).was_called(1)
-        assert.spy(Pkg.install).was_called_with(match.ref(dummy), {
-            version = "1.0.0",
-        })
-    end)
-end)
-
-describe("mason-lspconfig setup_handlers", function()
-    server_mappings.lspconfig_to_package["dummylsp"] = "dummy"
-    server_mappings.package_to_lspconfig["dummy"] = "dummylsp"
-    filetype_mappings.dummylang = { "dummylsp" }
-
-    it("should call default handler", function()
-        stub(registry, "get_installed_package_names")
-        registry.get_installed_package_names.returns { "dummy" }
-        local default_handler = spy.new()
-
-        mason_lspconfig.setup_handlers { default_handler }
-
-        assert.spy(default_handler).was_called(1)
-        assert.spy(default_handler).was_called_with "dummylsp"
-    end)
-
-    it("should call dedicated handler", function()
-        stub(registry, "get_installed_package_names")
-        registry.get_installed_package_names.returns { "dummy" }
-        local dedicated_handler = spy.new()
-        local default_handler = spy.new()
-
-        mason_lspconfig.setup_handlers {
-            default_handler,
-            ["dummylsp"] = dedicated_handler,
-        }
-
-        assert.spy(default_handler).was_called(0)
-        assert.spy(dedicated_handler).was_called(1)
-        assert.spy(dedicated_handler).was_called_with "dummylsp"
-    end)
-
-    it("should print warning if registering handler for non-existent server name", function()
-        spy.on(vim, "notify")
-        mason_lspconfig.setup_handlers {
-            doesnt_exist_server = spy.new(),
-        }
-        assert.spy(vim.notify).was_called(1)
-        assert.spy(vim.notify).was_called_with(
-            "[mason.nvim] mason-lspconfig.setup_handlers: Received handler for unknown lspconfig server name: doesnt_exist_server.",
-            vim.log.levels.WARN
-        )
-    end)
-end)
diff --git a/tests/minimal_debug_init.lua b/tests/minimal_debug_init.lua
deleted file mode 100644
index 82a8b0d2..00000000
--- a/tests/minimal_debug_init.lua
+++ /dev/null
@@ -1,61 +0,0 @@
-local on_windows = vim.loop.os_uname().version:match "Windows"
-
-local function join_paths(...)
-    local path_sep = on_windows and "\\" or "/"
-    local result = table.concat({ ... }, path_sep)
-    return result
-end
-
-vim.opt.runtimepath = vim.env.VIMRUNTIME
-vim.opt.completeopt = "menu"
-
-local temp_dir = vim.loop.os_getenv "TEMP" or "/tmp"
-
-vim.opt.packpath = join_paths(temp_dir, "mason-debug", "site")
-
-local package_root = join_paths(temp_dir, "mason-debug", "site", "pack")
-local install_path = join_paths(package_root, "packer", "start", "packer.nvim")
-local compile_path = join_paths(install_path, "plugin", "packer_compiled.lua")
-
-local function load_plugins()
-    require("packer").startup {
-        {
-            "wbthomason/packer.nvim",
-            "neovim/nvim-lspconfig",
-            "williamboman/mason.nvim",
-        },
-        config = {
-            package_root = package_root,
-            compile_path = compile_path,
-        },
-    }
-end
-
-function _G.load_config()
-    local lspconfig = require "lspconfig"
-
-    local function on_attach(client, bufnr)
-        vim.api.nvim_buf_set_option(bufnr, "omnifunc", "v:lua.vim.lsp.omnifunc")
-    end
-
-    require("mason").setup {
-        log = vim.log.levels.DEBUG,
-    }
-
-    -- ==================================================
-    -- ========= SETUP RELEVANT SERVER(S) HERE! =========
-    -- ==================================================
-    --
-    -- lspconfig.sumneko_lua.setup { on_attach = on_attach }
-end
-
-if vim.fn.isdirectory(install_path) == 0 then
-    vim.fn.system { "git", "clone", "https://github.com/wbthomason/packer.nvim", install_path }
-    load_plugins()
-    require("packer").sync()
-    vim.cmd [[autocmd User PackerComplete ++once lua load_config()]]
-else
-    load_plugins()
-    require("packer").sync()
-    _G.load_config()
-end