diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..bacd807
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,30 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container: alpine:latest
+
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v2
+
+      - name: Install dependencies and Neovim
+        run: |
+          apk update
+          apk add neovim git curl
+
+      - name: Install Plenary
+        run: |
+          mkdir -p ~/.config/nvim/pack/plenary/start
+          git clone --depth 1 /~https://github.com/nvim-lua/plenary.nvim.git ~/.config/nvim/pack/plenary/start/plenary.nvim
+
+      - name: Run tests
+        run: |
+          nvim --headless -c "PlenaryBustedFile tests/init.lua"
diff --git a/README.md b/README.md
index 5cd4332..53fd397 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # 🔖 Recall
 
+![Tests](/~https://github.com/fnune/recall.nvim/actions/workflows/test.yml/badge.svg)
+
 Recall refines the use of [Neovim marks][marks] by focusing on global marks,
 streamlining their usage and enhancing their visibility and navigability.
 
diff --git a/lua/recall/marking.lua b/lua/recall/marking.lua
index d74547a..ac877a0 100644
--- a/lua/recall/marking.lua
+++ b/lua/recall/marking.lua
@@ -54,6 +54,11 @@ M.remove_mark_if_exists = function()
 end
 
 function M.set_global_mark()
+  if vim.api.nvim_buf_get_name(0) == "" then
+    print("Cannot set a global mark in an unsaved buffer")
+    return
+  end
+
   local mark = M.next_available_mark()
   if mark then
     vim.cmd("mark " .. mark)
diff --git a/tests/init.lua b/tests/init.lua
new file mode 100644
index 0000000..b52b3ee
--- /dev/null
+++ b/tests/init.lua
@@ -0,0 +1,123 @@
+local luv = require("luv")
+local recall = require("recall")
+
+local function set_lines(buffer, count)
+  local lines = {}
+  for i = 1, count do
+    table.insert(lines, i .. "Lorem ipsum dolor sit amet, consectetur adipiscing elit...")
+  end
+  vim.api.nvim_buf_set_lines(buffer, 0, -1, false, lines)
+end
+
+local function place_cursor(line, column)
+  vim.api.nvim_win_set_cursor(0, { line, column })
+end
+
+local function count_signs(buffer)
+  local signs = vim.fn.sign_getplaced(buffer, { name = "RecallMark" })[1].signs
+  return #signs
+end
+
+describe("Recall", function()
+  local bufnr
+  local line_count = 100
+  local temp_paths = {}
+
+  before_each(function()
+    recall.setup({})
+
+    bufnr = vim.api.nvim_create_buf(true, false)
+    vim.api.nvim_set_current_buf(bufnr)
+    set_lines(bufnr, line_count)
+
+    local temp_path = luv.os_tmpdir() .. "/nvim-recall-test-" .. luv.hrtime() .. ".txt"
+    table.insert(temp_paths, temp_path)
+
+    vim.api.nvim_buf_set_name(bufnr, temp_path)
+    vim.api.nvim_buf_set_option(bufnr, "modified", false)
+    vim.cmd("w")
+  end)
+
+  after_each(function()
+    for _, temp_path in ipairs(temp_paths) do
+      os.remove(temp_path)
+    end
+    temp_paths = {}
+  end)
+
+  it("can toggle marks and show/hide signs", function()
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 1)
+
+    place_cursor(10, 0)
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 2)
+
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 1)
+
+    place_cursor(1, 0)
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 0)
+  end)
+
+  it("can toggle marks regardless of the column", function()
+    place_cursor(1, 0)
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 1)
+
+    place_cursor(1, 5)
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 0)
+  end)
+
+  it("does not set a mark on an unsaved buffer", function()
+    assert.are.equal(count_signs(bufnr), 0)
+
+    bufnr = vim.api.nvim_create_buf(true, false)
+    vim.api.nvim_set_current_buf(bufnr)
+
+    recall.toggle()
+    assert.are.equal(count_signs(bufnr), 0)
+  end)
+
+  it("can navigate to next and previous marks", function()
+    local a_pos = { 1, 1 }
+    place_cursor(unpack(a_pos))
+    recall.toggle()
+
+    local b_pos = { 10, 1 }
+    place_cursor(unpack(b_pos))
+    recall.toggle()
+
+    local c_pos = { 20, 1 }
+    place_cursor(unpack(c_pos))
+    recall.toggle()
+
+    recall.goto_prev()
+    assert.are.same(b_pos, vim.api.nvim_win_get_cursor(0))
+
+    recall.goto_prev()
+    assert.are.same(a_pos, vim.api.nvim_win_get_cursor(0))
+
+    recall.goto_next()
+    assert.are.same(b_pos, vim.api.nvim_win_get_cursor(0))
+
+    recall.goto_next()
+    assert.are.same(c_pos, vim.api.nvim_win_get_cursor(0))
+
+    recall.goto_prev()
+    assert.are.same(b_pos, vim.api.nvim_win_get_cursor(0))
+  end)
+
+  it("can clear all marks", function()
+    recall.toggle()
+    place_cursor(10, 0)
+    recall.toggle()
+    place_cursor(20, 0)
+    recall.toggle()
+
+    recall.clear()
+    assert.are.equal(count_signs(bufnr), 0)
+  end)
+end)