Get explicit parser installation into test suite

Now if you're running the test suite locally, it won't rely on you
having manually installed the parser. Now it checks and makes sure
they're all installed.

This also brings parity to local runs vs github CI runs - both ensure
the same parsers.

Author: aaronik

.github/workflows/test.yml

@@ -24,12 +24,11 @@ jobs:
         git clone https://github.com/nvim-lua/plenary.nvim.git
         mv plenary.nvim $HOME/.local/share/nvim/lazy/
 
-    - name: Install nvim-treesitter and parsers
+    - name: Install nvim-treesitter
       run: |
         mkdir -p $HOME/.local/share/nvim/lazy/
         git clone https://github.com/nvim-treesitter/nvim-treesitter.git
         mv nvim-treesitter $HOME/.local/share/nvim/lazy/
-        nvim --headless --noplugin -u tests/minimal_init.lua -c "TSInstall! python rust haskell html javascript c_sharp" -c "quit"
 
     - name: Run luacheck type check / linter
       run: |

tests/fixtures/ruby.rb

@@ -2,11 +2,13 @@
 class BankAccount
   attr_accessor :balance, :owner
 
+  # This is ruby code
   def initialize(balance = 0, owner = 'Unknown')
     @balance = balance
     @owner = owner
   end
 
+  # This does what you think
   def deposit(amount)
     if amount > 0
       @balance += amount
@@ -16,13 +18,16 @@ def deposit(amount)
     end
   end
 
+  # deposit 5
   deposit(5, deposit(5))
 
+  # allows you to withdraw
   def withdraw(amount)
     return nil unless deposit?(amount)
     @balance -= amount
   end
 
+  # deposit?
   def deposit?(amount)
     lambda { |x| x > 0 }[amount]
   end

tests/minimal_init.lua

@@ -9,5 +9,29 @@ vim.opt.swapfile = false
 vim.cmd("runtime! plugin/treewalker.nvim")
 vim.cmd("runtime! plugin/plenary.vim")
 vim.cmd("runtime! plugin/nvim-treesitter")
-require('nvim-treesitter').setup()
+require('nvim-treesitter.configs').setup {
+    ensure_installed = {
+        "lua",
+        "python",
+        "rust",
+        "haskell",
+        "html",
+        "javascript",
+        "c_sharp",
+        "typescript",
+        "php",
+        "markdown",
+        "ruby",
+    },
+    sync_install = true,
+    auto_install = true,
+    ignore_install = {},
+    modules = {}
+}
+
+-- These are required lest nvim not be able to tell these parsers are installed
+vim.treesitter.language.register('ruby', { 'rb' })
+-- TODO Why on earth does this break tests. Isn't the md parser supposed to come by default?
+-- vim.treesitter.language.register('markdown', { 'md' })
+
 dofile("plugin/init.lua") -- get the Treewalker command present

tests/treewalker/c_sharp_spec.lua

@@ -8,6 +8,8 @@ describe("Movement in a C Sharp file", function()
     load_fixture("/c-sharp.cs")
   end)
 
+  h.ensure_has_parser()
+
   it("works", function()
     vim.fn.cursor(7, 5)
     tw.move_down()

tests/treewalker/c_spec.lua

@@ -1,13 +1,16 @@
 local load_fixture = require "tests.load_fixture"
 local assert = require "luassert"
 local tw = require 'treewalker'
+local h = require 'tests.treewalker.helpers'
 local lines = require 'treewalker.lines'
 
 describe("Swapping in a c file:", function()
   before_each(function()
     load_fixture("/c.c")
   end)
 
+  h.ensure_has_parser()
+
   it("swaps right, when cursor is inside a string, the whole string", function()
     vim.fn.cursor(14, 17) -- the o in one
     assert.same('        printf("one\\n", "two\\n");', lines.get_line(14))

tests/treewalker/haskell_spec.lua

@@ -7,6 +7,8 @@ describe("Movement in a haskell file: ", function()
     load_fixture("/haskell.hs")
   end)
 
+  h.ensure_has_parser()
+
   it("moves out of a nested node", function()
     vim.fn.cursor(22, 3)
     tw.move_out()

tests/treewalker/helpers.lua

@@ -26,4 +26,15 @@ M.feed_keys = function(keys)
   vim.api.nvim_feedkeys(termcodes, 'mtx', false)
 end
 
+-- This is more for the test suite itself and ensuring that it's operating correctly.
+-- Makes sure there's no missing parser for the loaded file in the current buffer
+M.ensure_has_parser = function()
+  it("the test suite has the parser for the requested filetype", function()
+    local ok = pcall(vim.treesitter.get_parser)
+    if not ok then
+      error(string.format("Test suite is missing parser for ft [%s]", vim.bo.ft))
+    end
+  end)
+end
+
 return M

tests/treewalker/html_spec.lua

@@ -7,6 +7,8 @@ describe("Movement in an html file", function()
     load_fixture("/html.html")
   end)
 
+  h.ensure_has_parser()
+
   it("doesn't stop on footers", function()
     vim.fn.cursor(10, 5)
     tw.move_down()

tests/treewalker/lua_spec.lua

@@ -10,6 +10,8 @@ describe("Movement in a regular lua file: ", function()
     load_fixture("/lua.lua")
   end)
 
+  h.ensure_has_parser()
+
   it("moves up and down at the same pace", function()
     vim.fn.cursor(1, 1) -- Reset cursor
     tw.move_down()

tests/treewalker/lua_spec_spec.lua

@@ -9,6 +9,8 @@ describe("Movement in a lua spec file: ", function()
     load_fixture("/lua-spec.lua")
   end)
 
+  h.ensure_has_parser()
+
   -- go to first describe
   local function go_to_describe()
     vim.fn.cursor(1, 1)