test: firefox bookmarks spec

Also, use a flag to export private functions/variables during testing.
This is the recommended approach as mentioned here:
http://olivinelabs.com/busted/#private

lua/telescope/_extensions/bookmarks/firefox.lua

@@ -121,4 +121,8 @@ function firefox.collect_bookmarks(state)
   return bookmarks
 end
 
+if _TEST then
+  firefox._get_profile_dir = get_profile_dir
+end
+
 return firefox

spec/conftest.lua

@@ -6,3 +6,8 @@ vim.opt.runtimepath:append {
   cwd .. "/.deps/telescope.nvim",
   cwd .. "/.deps/plenary.nvim",
 }
+
+-- A flag to export private elements from the module for testing purposes.
+-- The element name will be prefixed with an underscore to avoid collision.
+---@see http://olivinelabs.com/busted/#private
+_G._TEST = true

spec/fixtures/Library/Application Support/Firefox/Profiles/dev-edition-default/places.sqlite

@@ -0,0 +1 @@
+../default-release/places.sqlite

spec/fixtures/Library/Application Support/Firefox/profiles.ini

@@ -0,0 +1,22 @@
+[Profile1]
+Name=default-release
+IsRelative=1
+Path=Profiles/default-release
+Default=1
+
+[Profile0]
+Name=dev-edition-default
+IsRelative=1
+Path=Profiles/dev-edition-default
+
+[General]
+StartWithLastProfile=1
+Version=2
+
+[Install1]
+Default=Profiles/dev-edition-default
+Locked=1
+
+[Install2]
+Default=Profiles/default-release
+Locked=1

spec/unit/firefox_spec.lua

@@ -0,0 +1,179 @@
+local utils = require "telescope._extensions.bookmarks.utils"
+
+local profiles = {
+  -- There was some parse error, so an empty table was returned.
+  parse_failure = {},
+
+  -- Default test profile config.
+  default_profile = {
+    Profile0 = {
+      Name = "default-release",
+      IsRelative = 1,
+      Path = "Profiles/default-release",
+      Default = 1,
+    },
+    Profile1 = {
+      Name = "dev-edition-default",
+      -- This profile contains absolute path to the profile directory.
+      IsRelative = 0,
+      Path = "Profiles/dev-edition-default",
+    },
+  },
+
+  -- There is no default profile in this config.
+  no_default_profile = {
+    Profile0 = {
+      Name = "default-release",
+      IsRelative = 1,
+      Path = "Profiles/default-release",
+    },
+  },
+}
+
+describe("firefox", function()
+  -- Insulate this block to avoid `ini.load` being overridden in other blocks.
+  insulate("get_profile_dir", function()
+    local match = require "luassert.match"
+    local ini = require "telescope._extensions.bookmarks.parser.ini"
+    local firefox = require "telescope._extensions.bookmarks.firefox"
+
+    -- Override the original function to load the data directly from the
+    -- "profiles" table defined above. The first part of the path is used as
+    -- the key which is the `os_homedir` in the state table.
+    ini.load = function(path)
+      local key = vim.split(path, "/")[1]
+      return profiles[key]
+    end
+
+    before_each(function()
+      stub(utils, "warn")
+    end)
+
+    after_each(function()
+      utils.warn:revert()
+    end)
+
+    it("should warn if OS not supported", function()
+      local profile_dir = firefox._get_profile_dir { os_name = "random" }
+
+      assert.is_nil(profile_dir)
+      assert.stub(utils.warn).was_called_with(
+        match.matches "Unsupported OS for firefox browser"
+      )
+    end)
+
+    it("should warn if failed to parse profiles.ini", function()
+      local profile_dir = firefox._get_profile_dir {
+        os_name = "Darwin",
+        os_homedir = "parse_failure",
+      }
+
+      assert.is_nil(profile_dir)
+      assert.stub(utils.warn).was_called_with(
+        match.matches "Unable to parse firefox profiles config file"
+      )
+    end)
+
+    it("should return default profile directory", function()
+      local profile_dir = firefox._get_profile_dir {
+        os_name = "Darwin",
+        os_homedir = "default_profile",
+      }
+
+      assert.is_not_nil(profile_dir)
+      assert.is_true(vim.endswith(profile_dir, "Profiles/default-release"))
+    end)
+
+    it("should return user given profile directory", function()
+      local profile_dir = firefox._get_profile_dir {
+        os_name = "Darwin",
+        os_homedir = "default_profile",
+        firefox_profile_name = "dev-edition-default",
+      }
+
+      assert.is_not_nil(profile_dir)
+      -- Also testing if the `IsRelative` key is being considered or not.
+      assert.are_equal(profile_dir, "Profiles/dev-edition-default")
+    end)
+
+    it("should warn if user given profile does not exist", function()
+      local profile_dir = firefox._get_profile_dir {
+        os_name = "Darwin",
+        os_homedir = "default_profile",
+        firefox_profile_name = "random",
+      }
+
+      assert.is_nil(profile_dir)
+      assert.stub(utils.warn).was_called_with(
+        match.matches "Given firefox profile does not exist"
+      )
+    end)
+
+    it("should warn if unable to deduce default profile", function()
+      local profile_dir = firefox._get_profile_dir {
+        os_name = "Darwin",
+        os_homedir = "no_default_profile",
+      }
+
+      assert.is_nil(profile_dir)
+      assert.stub(utils.warn).was_called_with(
+        match.matches "Unable to deduce the default firefox profile name"
+      )
+    end)
+  end)
+
+  describe("collect_bookmarks", function()
+    local firefox = require "telescope._extensions.bookmarks.firefox"
+
+    it("should parse bookmarks data", function()
+      local bookmarks = firefox.collect_bookmarks {
+        os_name = "Darwin",
+        os_homedir = "spec/fixtures",
+      }
+
+      assert.are.same(bookmarks, {
+        {
+          name = "GitHub",
+          path = "GitHub",
+          url = "https://github.com/",
+        },
+        {
+          name = "Google",
+          path = "search/Google",
+          url = "https://google.com/",
+        },
+        {
+          name = "DuckDuckGo",
+          path = "search/nested/DuckDuckGo",
+          url = "https://duckduckgo.com/",
+        },
+      })
+    end)
+
+    it("should parse bookmarks data for given firefox profile", function()
+      local bookmarks = firefox.collect_bookmarks {
+        os_name = "Darwin",
+        os_homedir = "spec/fixtures",
+        firefox_profile_name = "dev-edition-default",
+      }
+
+      assert.are.same(bookmarks, {
+        {
+          name = "GitHub",
+          path = "GitHub",
+          url = "https://github.com/",
+        },
+        {
+          name = "Google",
+          path = "search/Google",
+          url = "https://google.com/",
+        },
+        {
+          name = "DuckDuckGo",
+          path = "search/nested/DuckDuckGo",
+          url = "https://duckduckgo.com/",
+        },
+      })
+    end)
+  end)
+end)