omnisharp-extended-lsp.nvim

Extended LSP handlers and additional commands that support and are aware of OmniSharp $metadata documents (e.g. decompilation) and source generated documents.

Currently supported commands:

• textDocument/definition
• textDocument/typeDefinition
• textDocument/references
• textDocument/implementation

Related issue on $metadata documents: OmniSharp/omnisharp-roslyn#2238

How to use

There are 2 ways to use the plugin, using custom command or overriding lsp handler.

(tested with Neovim 0.9.5 on Windows and 0.10.0 nightly on MacOS)

Custom command (Optimal)

Using provided custom command for each supported action:

-- replaces vim.lsp.buf.definition()
nnoremap gd <cmd>lua require('omnisharp_extended').lsp_definition()<cr>

-- replaces vim.lsp.buf.type_definition()
nnoremap <leader>D <cmd>lua require('omnisharp_extended').lsp_type_definition()<cr>

-- replaces vim.lsp.buf.references()
nnoremap gr <cmd>lua require('omnisharp_extended').lsp_references()<cr>

-- replaces vim.lsp.buf.implementation()
nnoremap gi <cmd>lua require('omnisharp_extended').lsp_implementation()<cr>

These commands will call appropriate OmniSharp provided LSP command directly (e.g. o#/v2/gotodefinition instead of textDocument/definition). OmniSharp commands provide information about metadata files (decompiled assemblies and such) and source generated files. If results contain any of these files, the handler will then try to create read-only buffers before bringing up quickfix list or navigating to single result.

Custom command for Telescope

There are also commands provided specifically for nvim-telescope users:

nnoremap gr <cmd>lua require('omnisharp_extended').telescope_lsp_references()<cr>
-- options are supported as well
nnoremap gd <cmd>lua require('omnisharp_extended').telescope_lsp_definition({ jump_type = "vsplit" })<cr>
nnoremap <leader>D <cmd>lua require('omnisharp_extended').telescope_lsp_type_definition()<cr>
nnoremap gi <cmd>lua require('omnisharp_extended').telescope_lsp_implementation()<cr>

Custom handler (Suboptimal)

Using provided custom LSP handler for each supported action:

local config = {
  ...
  handlers = {
    ["textDocument/definition"] = require('omnisharp_extended').definition_handler,
    ["textDocument/typeDefinition"] = require('omnisharp_extended').type_definition_handler,
    ["textDocument/references"] = require('omnisharp_extended').references_handler,
    ["textDocument/implementation"] = require('omnisharp_extended').implementation_handler,
  },
  ...
}

require'lspconfig'.omnisharp.setup(config)

Custom handler is invoked for results of respective LSP native command (e.g. vim.lsp.buf.definition()). The handler then checks the results and if it determines that the result may contain non-local files (metadata, source generated) or that the request was made from within metadata file, it will retry the request using Custom command method, mentioned above. This means, that in some cases, LSP will be called twice, compared to always once, when using a command approach (not counting when there is a need to retrieve metadata/source generated file contents).

OmniSharp settings

For decompilation to work, OmniSharp extension for decompilation support might need to be enabled. See omnisharp wiki for information where omnisharp.json needs to be placed (~/.omnisharp/omnisharp.json).

{
  "RoslynExtensionsOptions": {
    "enableDecompilationSupport": true
  }
}

Important notes

• Plugin searches for LSP server configured with the name omnisharp or omnisharp_mono, so if your server is configured using a different name, this will not work out of the box.
• Navigation from within source generated files does not seem to be supported by omnisharp itself. Source generated files are technically identified by 2 UUID's, but gotodefinition expects a file name, so technically these 2 can't map to each other. Maybe in the future omnisharp devs will think of a way to make this work.
• Telescope preview does not work for "special" files as they are not actually accessible files. It should be possible to modify buffer_previewer_maker to handle this, but currently has not been implemented.