legacy-razor.nvim

Development happens at https://git.thenoetrevino.com/noe.trevino/legacy-razor.nvim. GitHub is a read-only mirror. Please open issues and pull requests there.

Neovim integration for legacy-razor-ls - a language server that brings hover, completion, document-highlight, and live diagnostics to classic ASP.NET MVC (System.Web) Razor views, which no modern tooling understands. Plus a whole-app compile check into the quickfix list.

@model BalanceHistoryViewModel
...
@Model.TodayBalance      -- K -> "Currency BalanceHistoryViewModel.TodayBalance { get; set; }"
@Model.                  -- completion -> AccountHistoryItems, TodayBalance, FromDate, ...

The language server does the real work - it hosts the real System.Web.Razor v3 pipeline and Roslyn (see the server repo for how and why). This plugin is the thin Neovim client: it launches the server, routes .cshtml buffers to it, drives occurrence highlighting, gets Roslyn out of the way, and adds :LegacyRazorCheck.

Requirements

• Windows (the plugin is inert elsewhere, safe in shared dotfiles)
• .NET Framework 4.x (runtime, preinstalled on Windows)
• The web app must have been built (bin/ populated) so views resolve types
• The server binary - installed one of three ways (see below)

Install (lazy.nvim)

{
  "TheNoeTrevino/legacy-razor.nvim",
  enabled = vim.fn.has("win32") == 1,
  ft = "razor",
  cmd = { "LegacyRazorCheck", "LegacyRazorUpdate" },
  opts = {},
}

Then get the language server with any of:

• :LegacyRazorUpdate - downloads the prebuilt server (matched to this plugin's pinned version) into stdpath("data"). No .NET SDK required.
• :MasonInstall legacy-razor-ls - if you use mason.nvim.
• Your own build - clone legacy-razor-ls, dotnet build -c Release server/LegacyRazor.Server.csproj, and set lsp.server_exe to the resulting LegacyRazor.Server.exe. (Checked out beside this plugin, it's picked up automatically.)

The plugin resolves the binary in that order - override → mason → download → sibling build - and, if none is found, tells you exactly how to get one.

What you get

Open any .cshtml in a classic app and the legacy-razor LSP client attaches:

• Hover (K) - real C# quick-info on @Model.X, @Html helpers, locals.
• Completion - model members after @Model., into your completion engine.
• Document highlight - occurrences of the symbol under the cursor.
• Diagnostics - live, as you type (a typo'd @Model member is CS1061).

Plus :LegacyRazorCheck - a whole-app aspnet_compiler sweep into quickfix, for checking every view at once.

Options (defaults)

{
  lsp = {
    enabled = true,
    server_exe = nil,          -- explicit path; nil = auto-resolve (mason/download/sibling)
    document_highlight = true, -- occurrence highlighting on CursorHold
    suppress_roslyn = true,    -- detach Roslyn/OmniSharp from classic views
    notify_errors = true,      -- warn once if the server isn't installed
  },
  -- whole-app aspnet_compiler sweep (:LegacyRazorCheck)
  aspnet_compiler = nil,       -- explicit path; nil = auto-detect
  open_quickfix = true,
  check_on_save = false,
}

suppress_roslyn matters if you run roslyn.nvim: it also attaches to .cshtml (as razor) but can't model classic views, so it only emits "No information available" hover and bogus "unnecessary using" diagnostics. This detaches it from classic System.Web views only - your .cs and ASP.NET Core .razor keep their Roslyn client.

Architecture

Neovim (vim.lsp client)                 lua/legacy-razor/
  │  LSP over stdio                       ├─ project    app-root + view detection
  │  (one server per app root)            ├─ lsp        attach + Roslyn takeover
  ▼                                       ├─ server     resolve/download the server binary
legacy-razor-ls (separate repo)          ├─ compiler   aspnet_compiler -> quickfix
  the LegacyRazor.Server.exe process      └─ init       setup + :LegacyRazorCheck / :LegacyRazorUpdate

Development

make test        # plenary-busted specs (headless Neovim)
make fmt         # stylua
make fmt-check   # stylua --check (CI)

make and stylua install via scoop; the underlying commands also run standalone.

Limitations

• Hovering the bare Model keyword (not a member) may be empty; members work.
• Classic Razor only; ASP.NET Core Razor is already served by rzls/Roslyn.
• Windows only (classic ASP.NET is .NET Framework).