Refactor link cleaning and transformation functions

README.md

@@ -25,6 +25,7 @@ start neovim with  `nvim --cmd "set rtp+=$(pwd)" .` to automatically load the fi
 * [ ] options
  * [x] zettel anchor separator
  * [x] zettel extension
+ * [ ] link style (wiki/markdown) custom?
  * [ ] recursive lookup for zettel
  * [ ] zettel anchor regex
 * [ ] backlinks (via rg for filename anchor?)

lua/zettelkasten/link.lua

@@ -3,17 +3,52 @@ local L = {}
 local o = require 'zettelkasten.options'
 local a = require 'zettelkasten.anchor'
 
--- Returns a link to a markdown file with the date replaced with a zettel anchor,
--- and the text cleaned up to be useful in a link.
-function L.create_link_text(text, date)
-    text = text or ""
-    if text == "" then
-        text = "" .. a.create_anchor(date)
-    else
-        text = text:lower():gsub(" ", "-")
-        text = "" .. a.create_anchor(date) .. o.anchor().separator .. text
+-- TODO split up into clean/anchor/style functions, make private
+-- Returns a link to a markdown file with the anchor replaced with a zettel anchor,
+-- Returns the text passed in with the anchor passed in prepended,
+function L.prepend_anchor(anchor, text)
+    if not text or text == "" then return anchor end
+
+    text = anchor .. o.anchor().separator .. text
+    return text
 end
-    return text .. o.zettel().extension
+
+-- Returns the text cleaned up to be more useful in a link.
+-- Spaces are replaced by dashes and everything is lowercased.
+function L.clean(text)
+    text = text or ""
+    return text:lower():gsub(" ", "-")
+end
+
+-- Returns the untouched text with the extension set in options appended
+-- at the end.
+function L.append_extension(text) return text .. o.zettel().extension end
+
+local function check_link_empty(link)
+    if not link or link == "" then error("Link is not allowed to be empty.") end
+end
+
+local function trimmed(text)
+    return text:match '^()%s*$' and '' or text:match '^%s*(.*%S)'
+end
+
+-- Returns a markdown-compatible transformation of the link and text combination
+-- passed in.
+function L.style_markdown(link, text)
+    check_link_empty(link)
+
+    return "[" .. trimmed(text) .. "](" .. link .. ")"
+end
+
+-- Returns a wikilink-compatible transformation of the link and text combination
+-- passed in, adding the text as a pipe if it exists.
+function L.style_wiki(link, text)
+    check_link_empty(link)
+    local pipe = ""
+    text = trimmed(text)
+
+    if text and text ~= "" then pipe = "|" .. text end
+    return "[[" .. link .. pipe .. "]]"
 end
 
 return L

lua/zettelkasten/link_spec.lua

@@ -1,52 +1,91 @@
-ZK = require 'zettelkasten.link'
+link = require 'zettelkasten.link'
 Test_date = {year = 2019, month = 10, day = 29, hour = 16, min = 45}
 
 before_each(function() _G.vim = {g = {}, b = {}} end)
 after_each(function() _G.vim = nil end)
 
-describe("link creation", function()
-    it(
-        "should return a markdown link with only zettel anchor on no text passed in",
-        function()
-            assert.same("1910291645.md", ZK.create_link_text(nil, Test_date))
+describe("prepend_anchor", function()
+    it("should append text to link", function()
+        assert.same("1910291645_isappended",
+                    link.prepend_anchor("1910291645", "isappended"))
+    end)
+    it("should not add a separator if no text appended", function()
+        assert.same("1910291645", link.prepend_anchor("1910291645", ""))
     end)
 
-    it("should text to link", function()
-        assert.same("1910291645_isappended.md",
-                    ZK.create_link_text("isappended", Test_date))
+    it("should return solely the anchor if no text is passed in", function()
+        assert.same("1910291645", link.prepend_anchor("1910291645", nil))
     end)
-
-    it("should return lowercased link text", function()
-        assert.same("1910291645_yesiamshouting.md",
-                    ZK.create_link_text("YESIAMSHOUTING", Test_date))
+    it("should return solely the anchor if empty text is passed in", function()
+        assert.same("1910291645", link.prepend_anchor("1910291645", ""))
     end)
-
-    it("should return spaces in text replaced with dashes", function()
-        assert.same("1910291645_yes-indeed-a-space.md",
-                    ZK.create_link_text("yes indeed a space", Test_date))
-    end)
-
     it("should add contents of g:zettel_anchor_separator variable to link",
        function()
         vim.g.zettel_anchor_separator = "SEP"
-        assert.same("1910291645SEParated.md",
-                    ZK.create_link_text("arated", Test_date))
+        assert.same("1910291645SEParated",
+                    link.prepend_anchor("1910291645", "arated"))
     end)
     it("should add contents of b:zettel_anchor_separator variable to link",
        function()
         vim.b.zettel_anchor_separator = "---"
-        assert.same("1910291645---arated.md",
-                    ZK.create_link_text("arated", Test_date))
+        assert.same("1910291645---arated",
+                    link.prepend_anchor("1910291645", "arated"))
+    end)
 end)
 
-    it("should append the filetype set in g:zettel_extension", function()
-        vim.g.zettel_extension = ".something"
-        assert.same("1910291645_theworld.something",
-                    ZK.create_link_text("theworld", Test_date))
+describe("clean", function()
+    it("should return lowercased link text", function()
+        assert.same("yesiamshouting", link.clean("YESIAMSHOUTING"))
     end)
-    it("should append the filetype set in b:zettel_extension", function()
-        vim.b.zettel_extension = ".somethingelse"
-        assert.same("1910291645_theworld.somethingelse",
-                    ZK.create_link_text("theworld", Test_date))
+
+    it("should return spaces in text replaced with dashes", function()
+        assert.same("yes-indeed-a-space", link.clean("yes indeed a space"))
+    end)
+end)
+
+describe("append_extension", function()
+    it("should append the contents set in global zettel extension option",
+       function()
+        vim.g.zettel_extension = ".extension"
+        assert.same("myfile.extension", link.append_extension("myfile"))
+    end)
+    it("should append the contents set in global zettel extension option",
+       function()
+        vim.b.zettel_extension = ".bufext"
+        assert.same("myfile.bufext", link.append_extension("myfile"))
+    end)
+end)
+
+describe("style_markdown", function()
+    it("should correctly apply transformations to link and text", function()
+        assert.same("[My AWESOME Link](1910291645_my-awesome-link.md)",
+                    link.style_markdown("1910291645_my-awesome-link.md",
+                                        "My AWESOME Link"))
+    end)
+    it("should trim whitespace for the text area", function()
+        assert.same("[](1910291645_my-awesome-link.md)",
+                    link.style_markdown("1910291645_my-awesome-link.md", "   "))
+        assert.same("[hi](1910291645_my-awesome-link.md)", link.style_markdown(
+                        "1910291645_my-awesome-link.md", "  hi     "))
+    end)
+    it("should error if no link provided", function()
+        assert.is_error(function() link.style_markdown("", "mytext") end)
+        assert.is_error(function() link.style_markdown(nil, "mytext") end)
+    end)
+end)
+
+describe("style_wiki", function()
+    it("should error if no link provided", function()
+        assert.is_error(function() link.style_wiki("", "mytext") end)
+        assert.is_error(function() link.style_wiki(nil, "mytext") end)
+    end)
+    it("should correctly apply transformations to link and text", function()
+        assert.same("[[1910291645|My AWESOME Link]]",
+                    link.style_wiki("1910291645", "My AWESOME Link"))
+    end)
+    it("should trim whitespace for the text area", function()
+        assert.same("[[1910291645]]", link.style_wiki("1910291645", "   "))
+        assert.same("[[1910291645|hi]]",
+                    link.style_wiki("1910291645", "  hi     "))
     end)
 end)