feat(builtin.lsp): implement builtin handlers for lsp.(incoming|outgoing)_calls (#1484)

Fixes #863

4 files changed, 128 insertions, 2 deletions

diff --git a/README.md b/README.md
index 5e6bd52..56c1d17 100644
--- a/README.md
+++ b/README.md
@@ -299,6 +299,8 @@ Built-in functions. Ready to be bound to any key you like.
 | Functions                                   | Description                                                                                                               |
 |---------------------------------------------|---------------------------------------------------------------------------------------------------------------------------|
 | `builtin.lsp_references`                    | Lists LSP references for word under the cursor                                                                            |
+| `builtin.lsp_incoming_calls`                | Lists LSP incoming calls for word under the cursor                                                                        |
+| `builtin.lsp_outgoing_calls`                | Lists LSP outgoing calls for word under the cursor                                                                        |
 | `builtin.lsp_document_symbols`              | Lists LSP document symbols in the current buffer                                                                          |
 | `builtin.lsp_workspace_symbols`             | Lists LSP document symbols in the current workspace                                                                       |
 | `builtin.lsp_dynamic_workspace_symbols`     | Dynamically Lists LSP for all workspace symbols                                                                           |
diff --git a/doc/telescope.txt b/doc/telescope.txt
index ce171f1..78cc7e4 100644
--- a/doc/telescope.txt
+++ b/doc/telescope.txt
@@ -1464,6 +1464,32 @@ builtin.lsp_references({opts})            *telescope.builtin.lsp_references()*
                                           section (default: 30)
 
 
+builtin.lsp_incoming_calls({opts})    *telescope.builtin.lsp_incoming_calls()*
+    Lists LSP incoming calls for word under the cursor, jumps to reference on
+    `<cr>`
+
+
+    Parameters: ~
+        {opts} (table)  options to pass to the picker
+
+    Options: ~
+        {show_line} (boolean)  show results text (default: true)
+        {trim_text} (boolean)  trim results text (default: false)
+
+
+builtin.lsp_outgoing_calls({opts})    *telescope.builtin.lsp_outgoing_calls()*
+    Lists LSP outgoing calls for word under the cursor, jumps to reference on
+    `<cr>`
+
+
+    Parameters: ~
+        {opts} (table)  options to pass to the picker
+
+    Options: ~
+        {show_line} (boolean)  show results text (default: true)
+        {trim_text} (boolean)  trim results text (default: false)
+
+
 builtin.lsp_definitions({opts})          *telescope.builtin.lsp_definitions()*
     Goto the definition of the word under the cursor, if there's only one,
     otherwise show all options in Telescope
diff --git a/lua/telescope/builtin/init.lua b/lua/telescope/builtin/init.lua
index 7a3fb14..20d9812 100644
--- a/lua/telescope/builtin/init.lua
+++ b/lua/telescope/builtin/init.lua
@@ -378,6 +378,18 @@ builtin.jumplist = require_on_exported_call("telescope.builtin.internal").jumpli
 ---@field fname_width number: defines the width of the filename section (default: 30)
 builtin.lsp_references = require_on_exported_call("telescope.builtin.lsp").references
 
+--- Lists LSP incoming calls for word under the cursor, jumps to reference on `<cr>`
+---@param opts table: options to pass to the picker
+---@field show_line boolean: show results text (default: true)
+---@field trim_text boolean: trim results text (default: false)
+builtin.lsp_incoming_calls = require_on_exported_call("telescope.builtin.lsp").incoming_calls
+
+--- Lists LSP outgoing calls for word under the cursor, jumps to reference on `<cr>`
+---@param opts table: options to pass to the picker
+---@field show_line boolean: show results text (default: true)
+---@field trim_text boolean: trim results text (default: false)
+builtin.lsp_outgoing_calls = require_on_exported_call("telescope.builtin.lsp").outgoing_calls
+
 --- Goto the definition of the word under the cursor, if there's only one, otherwise show all options in Telescope
 ---@param opts table: options to pass to the picker
 ---@field jump_type string: how to goto definition if there is only one, values: "tab", "split", "vsplit", "never"
diff --git a/lua/telescope/builtin/lsp.lua b/lua/telescope/builtin/lsp.lua
index 410a068..85fabb0 100644
--- a/lua/telescope/builtin/lsp.lua
+++ b/lua/telescope/builtin/lsp.lua
@@ -52,9 +52,93 @@ lsp.references = function(opts)
   end)
 end
 
-local function list_or_jump(action, title, opts)
-  opts = opts or {}
+local function call_hierarchy(opts, method, title, direction, item)
+  vim.lsp.buf_request(opts.bufnr, method, { item = item }, function(err, result)
+    if err then
+      vim.api.nvim_err_writeln("Error handling " .. title .. ": " .. err)
+      return
+    end
+
+    if not result or vim.tbl_isempty(result) then
+      return
+    end
+
+    local locations = {}
+    for _, ch_call in pairs(result) do
+      local ch_item = ch_call[direction]
+      for _, range in pairs(ch_call.fromRanges) do
+        table.insert(locations, {
+          filename = vim.uri_to_fname(ch_item.uri),
+          text = ch_item.name,
+          lnum = range.start.line + 1,
+          col = range.start.character + 1,
+        })
+      end
+    end
+
+    pickers.new(opts, {
+      prompt_title = title,
+      finder = finders.new_table {
+        results = locations,
+        entry_maker = opts.entry_maker or make_entry.gen_from_quickfix(opts),
+      },
+      previewer = conf.qflist_previewer(opts),
+      sorter = conf.generic_sorter(opts),
+      push_cursor_on_edit = true,
+      push_tagstack_on_edit = true,
+    }):find()
+  end)
+end
+
+local function pick_call_hierarchy_item(call_hierarchy_items)
+  if not call_hierarchy_items then
+    return
+  end
+  if #call_hierarchy_items == 1 then
+    return call_hierarchy_items[1]
+  end
+  local items = {}
+  for i, item in pairs(call_hierarchy_items) do
+    local entry = item.detail or item.name
+    table.insert(items, string.format("%d. %s", i, entry))
+  end
+  local choice = vim.fn.inputlist(items)
+  if choice < 1 or choice > #items then
+    return
+  end
+  return choice
+end
+
+local function calls(opts, direction)
+  local params = vim.lsp.util.make_position_params()
+  vim.lsp.buf_request(opts.bufnr, "textDocument/prepareCallHierarchy", params, function(err, result)
+    if err then
+      vim.api.nvim_err_writeln("Error when preparing call hierarchy: " .. err)
+      return
+    end
+
+    local call_hierarchy_item = pick_call_hierarchy_item(result)
+    if not call_hierarchy_item then
+      return
+    end
+
+    if direction == "from" then
+      call_hierarchy(opts, "callHierarchy/incomingCalls", "LSP Incoming Calls", direction, call_hierarchy_item)
+    else
+      call_hierarchy(opts, "callHierarchy/outgoingCalls", "LSP Outgoing Calls", direction, call_hierarchy_item)
+    end
+  end)
+end
+
+lsp.incoming_calls = function(opts)
+  calls(opts, "from")
+end
 
+lsp.outgoing_calls = function(opts)
+  calls(opts, "to")
+end
+
+local function list_or_jump(action, title, opts)
   local params = vim.lsp.util.make_position_params(opts.winnr)
   vim.lsp.buf_request(opts.bufnr, action, params, function(err, result, ctx, _)
     if err then
@@ -271,6 +355,8 @@ local feature_map = {
   ["type_definitions"] = "typeDefinitionProvider",
   ["implementations"] = "implementationProvider",
   ["workspace_symbols"] = "workspaceSymbolProvider",
+  ["incoming_calls"] = "callHierarchyProvider",
+  ["outgoing_calls"] = "callHierarchyProvider",
 }
 
 local function apply_checks(mod)