Feat: Add Basic Lua Test Suite (#115)

This MR adds a Lua test suite to the project, run via busted, and introduces tests for a number of the utility functions. Subsequent work will have to be done to test functions that use the `vim.api` scope and external packages to the plugin.

lua/gitlab/spec/util_spec.lua

@@ -0,0 +1,181 @@
+describe("utils/init.lua", function()
+  it("Loads package", function()
+    local utils_ok, _ = pcall(require, "gitlab.utils")
+    assert._is_true(utils_ok)
+  end)
+
+  local _, u = pcall(require, "gitlab.utils")
+  describe("extract", function()
+    it("Extracts a single value", function()
+      local t = { { one = 1, two = 2 }, { three = 3, four = 4 } }
+      local got = u.extract(t, "one")
+      local want = { 1 }
+      assert.are.same(want, got)
+    end)
+    it("Returns nothing with empty table", function()
+      local t = {}
+      local got = u.extract(t, "one")
+      local want = {}
+      assert.are.same(want, got)
+    end)
+  end)
+
+  describe("get_last_word", function()
+    it("Returns the last word in a sentence", function()
+      local sentence = "Hello world!"
+      local got = u.get_last_word(sentence)
+      local want = "world!"
+      assert.are.same(want, got)
+    end)
+    it("Returns an empty string without text", function()
+      local sentence = ""
+      local got = u.get_last_word(sentence)
+      local want = ""
+      assert.are.same(want, got)
+    end)
+    it("Returns whole string w/out divider", function()
+      local sentence = "Thisdoesnothavebreaks"
+      local got = u.get_last_word(sentence)
+      assert.are.same(sentence, got)
+    end)
+    it("Returns correct word w/ different divider", function()
+      local sentence = "this|uses|a|different|divider"
+      local got = u.get_last_word(sentence, "|")
+      local want = "divider"
+      assert.are.same(want, got)
+    end)
+  end)
+
+  describe("format_date", function()
+    local current_date = {
+      day = 19,
+      hour = 22,
+      isdst = false,
+      min = 0,
+      month = 11,
+      sec = 44,
+      wday = 1,
+      yday = 323,
+      year = 2023,
+    }
+    it("Returns days since a valid UTC timestamp", function()
+      local stamp = "2023-11-16T19:52:36.946Z"
+      local got = u.time_since(stamp, current_date)
+      local want = "3 days ago"
+      assert.are.same(want, got)
+    end)
+
+    it("Returns hours since a valid UTC timestamp", function()
+      local stamp = "2023-11-19T19:52:36.946Z"
+      local got = u.time_since(stamp, current_date)
+      local want = "2 hours ago"
+      assert.are.same(want, got)
+    end)
+    it("Returns readable time if > 1 year", function()
+      local stamp = "2011-11-19T19:52:36.946Z"
+      local got = u.time_since(stamp, current_date)
+      local want = "November 19, 2011"
+      assert.are.same(want, got)
+    end)
+  end)
+
+  describe("remove_first_value", function()
+    it("Removes the first value correctly", function()
+      local got = u.remove_first_value({ 1, 2 })
+      local want = { 2 }
+      assert.are.same(want, got)
+    end)
+    it("Handles a one-length list", function()
+      local got = u.remove_first_value({ 1 })
+      local want = {}
+      assert.are.same(want, got)
+    end)
+    it("Handles a zero-length list", function()
+      local got = u.remove_first_value({})
+      local want = {}
+      assert.are.same(want, got)
+    end)
+  end)
+
+  describe("table_size", function()
+    it("Works for associative tables", function()
+      local got = u.remove_first_value({ 1, 2 })
+      local want = { 2 }
+      assert.are.same(want, got)
+    end)
+    it("Handles a one-length list", function()
+      local got = u.remove_first_value({ 1 })
+      local want = {}
+      assert.are.same(want, got)
+    end)
+    it("Handles a zero-length list", function()
+      local got = u.remove_first_value({})
+      local want = {}
+      assert.are.same(want, got)
+    end)
+  end)
+
+  describe("contains", function()
+    it("Finds a value in a list", function()
+      local got = u.contains({ 1, 2 }, 1)
+      assert._is_true(got)
+    end)
+    it("Handles missing values", function()
+      local got = u.contains({ 1, 3, 4 }, 2)
+      assert._is_false(got)
+    end)
+    it("Handles empty lists", function()
+      local got = u.contains({}, 1)
+      assert._is_false(got)
+    end)
+  end)
+
+  describe("reverse", function()
+    it("Reverses the values in a list", function()
+      local got = u.reverse({ 1, 2, 3, 4 })
+      local want = { 4, 3, 2, 1 }
+      assert.are.same(got, want)
+    end)
+    it("Handles single value", function()
+      local got = u.reverse({ 1 })
+      local want = { 1 }
+      assert.are.same(got, want)
+    end)
+    it("Handles empty list", function()
+      local got = u.reverse({})
+      local want = {}
+      assert.are.same(got, want)
+    end)
+  end)
+
+  describe("spread", function()
+    it("Spreads the values", function()
+      local t1 = { 1, 2, 3 }
+      local t2 = { 4, 5, 6 }
+      local got = u.spread(t1, t2)
+      local want = { 1, 2, 3, 4, 5, 6 }
+      assert.are.same(got, want)
+    end)
+    it("Handles an empty t1 table", function()
+      local t1 = {}
+      local t2 = { 4, 5, 6 }
+      local got = u.spread(t1, t2)
+      local want = { 4, 5, 6 }
+      assert.are.same(got, want)
+    end)
+    it("Handles an empty t2 table", function()
+      local t1 = { 1, 2, 3 }
+      local t2 = {}
+      local got = u.spread(t1, t2)
+      local want = { 1, 2, 3 }
+      assert.are.same(got, want)
+    end)
+    it("Handles both empty tables", function()
+      local t1 = {}
+      local t2 = {}
+      local got = u.spread(t1, t2)
+      local want = {}
+      assert.are.same(got, want)
+    end)
+  end)
+end)