blink-icon-preview.nvim

Inline image previews in the blink.cmp documentation window, rendered by snacks.nvim's image module.

Built for icon-library completions — e.g. @phosphor-icons/react, whose LSP hover/completion docs embed every icon as a base64 SVG data URL (![img](data:image/svg+xml;base64,...)). Out of the box those show up as plain @regular — img text; with this plugin you see the actual icon.

Requirements

• Neovim 0.10+ (vim.base64); developed on 0.12
• snacks.nvim with image.enabled = true and image.doc.inline = true
• A terminal supporting the Kitty graphics protocol (Kitty, Ghostty, WezTerm)
• ImageMagick (magick) for SVG rasterization
• treesitter parsers for markdown and markdown_inline

Install (lazy.nvim)

{
  "shift-primal/blink-icon-preview.nvim",
  dependencies = { "folke/snacks.nvim" },
  -- setup() should run before snacks' first terminal detection;
  -- lazy-loading on InsertEnter is fine, `init` is safest:
  init = function()
    require("blink-icon-preview").setup()
  end,
}

Recommended snacks.nvim opts, so big-viewBox icons rasterize sharp but capped:

opts = {
  image = {
    convert = {
      magick = {
        vector = { "-density", "192", "-background", "none", "{src}[{page}]", "-resize", "256x256" },
      },
    },
  },
}

Configuration (defaults)

require("blink-icon-preview").setup({
  filetype = "blink-cmp-documentation",
  -- window options forced on docs popups that contain images
  wo = { wrap = false, conceallevel = 2 },
  -- plain-text marker that decides whether a popup "contains images"
  image_pattern = "data:image/",
  -- set SNACKS_KITTY=1 inside Kitty to skip snacks' async terminal detection
  kitty_override = true,
})

How it works

The docs buffer is registered as a markdown treesitter language so snacks' images.scm query can find image nodes in it, and snacks' doc renderer is attached on every popup (blink re-assigns the filetype each time the window opens, so the FileType autocmd fires per popup). The long ![img](data:...) line is concealed and wrap is disabled so the icon renders directly under its label.

patches.lua additionally hot-patches four bugs in snacks.image.doc at runtime (no files in the snacks installation are modified, so :Lazy update is safe). Each is a candidate upstream fix:

1. MIME dispatch — ^data:%w+/%w+;base64, never matches image/svg+xml (%w excludes +), so the data_img transform was skipped and the raw data URL was treated as a file path.
2. Extension — ft:match("^image/(%w+)$") also fails on svg+xml, falling back to png, so SVG content was cached as .png and rasterized without the vector pipeline.
3. Cache key — content_id = data:sub(1, 20) is identical for every SVG sharing a header, so all icons displayed the first icon's cached image.
4. Ranged find — doc.find passes row numbers where Query:iter_matches expects byte offsets (Neovim 0.12), so the ranged search used by inline rendering found no images. The patch scans the whole (tiny) docs buffer instead.

It also strips explicit width/height attributes from SVGs so ImageMagick rasterizes at the viewBox size (Phosphor icons declare 20x20 with a 256 viewBox — rendering 20px and upscaling looks pixelated), and warms up snacks' terminal detection at startup so the first popup is not delayed by it.