Add simple zettel retrieval function

lua/zettelkasten/list.lua

@@ -31,4 +31,12 @@ function ls.get_anchors_and_paths(path, recursive, options)
     return zettel
 end
 
+-- Returns the path to the zettel defined by the anchor argument.
+-- Take a list of zettel as an optional variable, without which
+-- it will use the (recursive) results of the zettel_root directory.
+function ls.get_zettel(anchor, all)
+    return all[anchor]
+end
+
+
 return ls

lua/zettelkasten/list_spec.lua

@@ -1,9 +1,7 @@
 ls = require'zettelkasten.list'
 -- these tests, I suppose, only work on unix due to the file structure
 
-describe("zettel listing", function()
-    before_each(function()
-        _G.get_api_mock = function(files)
+local function simple_api_mock(files)
     return {
         g = {},
         b = {},
@@ -21,9 +19,12 @@ describe("zettel listing", function()
         }
     }
 end
+
+describe("get_anchors_and_paths", function()
+    before_each(function()
+        get_api_mock = simple_api_mock
     end)
     after_each(function()
-        _G.get_api_mock = nil
         _G.vim = nil
     end)
 
@@ -138,5 +139,16 @@ describe("zettel listing", function()
         assert.same(expected, ls.get_anchors_and_paths('mydirectory', false, vim.g))
 
     end)
-
+end)
+
+describe("get_zettel", function()
+    it("should return the correct zettel by id", function()
+        local file_list = {
+            ["1910291645"] = "1910291645 myfile.md",
+            ["2345678901"] = "2345678901 another.md",
+        }
+        _G.vim = simple_api_mock(file_list)
+
+        assert.same("1910291645 myfile.md", ls.get_zettel("1910291645", file_list))
+    end)
 end)