fix(package): don't call vim API functions inside fast event (#730)

1 files changed, 104 insertions, 0 deletions

diff --git a/lua/mason-core/terminator.lua b/lua/mason-core/terminator.lua
new file mode 100644
index 00000000..b7acefe8
--- /dev/null
+++ b/lua/mason-core/terminator.lua
@@ -0,0 +1,104 @@
+local a = require "mason-core.async"
+
+-- Hasta la vista, baby.
+--                      ______
+--                    <((((((\\\
+--                    /      . }\
+--                    ;--..--._|}
+-- (\                 '--/\--'  )
+--  \\                | '-'  :'|
+--   \\               . -==- .-|
+--    \\               \.__.'   \--._
+--    [\\          __.--|       //  _/'--.
+--    \ \\       .'-._ ('-----'/ __/      \
+--     \ \\     /   __>|      | '--.       |
+--      \ \\   |   \   |     /    /       /
+--       \ '\ /     \  |     |  _/       /
+--        \  \       \ |     | /        /
+--  snd    \  \      \        /
+
+local M = {}
+
+---@async
+---@param handles InstallHandle[]
+---@param grace_ms integer
+local function terminate_handles(handles, grace_ms)
+    a.wait_all(vim.tbl_map(
+        ---@param handle InstallHandle
+        function(handle)
+            return function()
+                a.wait_first {
+                    function()
+                        if not handle:is_closed() then
+                            handle:terminate()
+                        end
+                        a.wait(function(resolve)
+                            if handle:is_closed() then
+                                resolve()
+                            else
+                                handle:once("closed", resolve)
+                            end
+                        end)
+                    end,
+                    function()
+                        a.sleep(grace_ms)
+                        if not handle:is_closed() then
+                            handle:kill(9) -- SIGKILL
+                        end
+                    end,
+                }
+            end
+        end,
+        handles
+    ))
+end
+
+local active_handles = {}
+
+---@parma handle InstallHandle
+function M.register(handle)
+    if handle:is_closed() then
+        return
+    end
+    active_handles[handle] = true
+    handle:once("closed", function()
+        active_handles[handle] = nil
+    end)
+end
+
+---@param grace_ms integer
+function M.terminate(grace_ms)
+    local handles = vim.tbl_keys(active_handles)
+    if #handles > 0 then
+        local package_names = vim.tbl_map(function(h)
+            return h.package.name
+        end, handles)
+        table.sort(package_names)
+
+        -- 1. Print warning message.
+        vim.api.nvim_echo({
+            {
+                "[mason.nvim] Neovim is exiting while packages are still installing. Terminating all installations…",
+                "WarningMsg",
+            },
+        }, true, {})
+        vim.cmd "redraw"
+
+        -- 2. Synchronously terminate all installation handles.
+        a.run_blocking(function()
+            terminate_handles(handles, grace_ms)
+        end)
+
+        -- 3. Schedule error message to be displayed so that Neovim prints it to the tty.
+        --    XXX: does this need to be conditional on which UIs are attached?
+        vim.schedule(function()
+            vim.api.nvim_err_writeln(
+                ("[mason.nvim] Neovim exited while the following packages were installing. Installation was aborted.\n- %s"):format(
+                    table.concat(package_names, #package_names > 5 and ", " or "\n- ")
+                )
+            )
+        end)
+    end
+end
+
+return M