add tests to CI

.github/workflows/test.yaml

@@ -0,0 +1,19 @@
+name: Test
+
+on: [push]
+
+jobs:
+
+  test:
+    name: Run Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: rhysd/action-setup-vim@v1
+        id: vim
+        with:
+          neovim: true
+          version: 0.9.5
+
+      - name: run test
+        run: make test

Makefile

@@ -0,0 +1,2 @@
+test:
+	nvim --headless -u ./tests/minimal_init.lua -i NONE -n --noplugin -c 'PlenaryBustedDirectory tests'

lua/lsp-preview/diff.lua

@@ -3,7 +3,6 @@
 -- for their work <3
 
 local lEdits = require("lsp-preview.buffer_edits")
-local minidiff = require("mini.diff")
 
 local M = {}
 
@@ -153,6 +152,7 @@ end
 
 ---@return string filetype
 function Edit:preview(bufnr, winid, opts)
+	local minidiff = require("mini.diff")
 	opts = opts or {}
 
 	-- set lines in buffer to the changed output