feat(fetch): add ability to download file instead of writing to stdout

2 files changed, 51 insertions, 7 deletions

diff --git a/lua/nvim-lsp-installer/core/fetch.lua b/lua/nvim-lsp-installer/core/fetch.lua
index d97da59b..4c0d1f25 100644
--- a/lua/nvim-lsp-installer/core/fetch.lua
+++ b/lua/nvim-lsp-installer/core/fetch.lua
@@ -12,28 +12,42 @@ local HEADERS = {
     iwr = ("-Headers @{'User-Agent' = '%s'}"):format(USER_AGENT),
 }
 
+---@alias FetchOpts {out_file:string}
+
 ---@async
 ---@param url string @The url to fetch.
-local function fetch(url)
+---@param opts FetchOpts
+local function fetch(url, opts)
+    opts = opts or {}
     log.fmt_debug("Fetching URL %s", url)
 
     local platform_specific = Result.failure()
 
     if platform.is_win then
-        platform_specific = powershell.command(
-            ([[Write-Output (iwr %s -UseBasicParsing -Uri %q).Content;]]):format(HEADERS.iwr, url)
-        )
+        if opts.out_file then
+            platform_specific = powershell.command(
+                ([[iwr %s -UseBasicParsing -Uri %q; -OutFile %q]]):format(HEADERS.iwr, url, opts.out_file)
+            )
+        else
+            platform_specific = powershell.command(
+                ([[Write-Output (iwr %s -UseBasicParsing -Uri %q).Content;]]):format(HEADERS.iwr, url)
+            )
+        end
     end
 
     return platform_specific
         :recover_catching(function()
-            return spawn.wget({ HEADERS.wget, "-nv", "-O", "-", url }):get_or_throw()
+            return spawn.wget({ HEADERS.wget, "-nv", "-O", opts.out_file or "-", url }):get_or_throw()
         end)
         :recover_catching(function()
-            return spawn.curl({ HEADERS.curl, "-fsSL", url }):get_or_throw()
+            return spawn.curl({ HEADERS.curl, "-fsSL", opts.out_file and { "-o", opts.out_file } or vim.NIL, url }):get_or_throw()
         end)
         :map(function(result)
-            return result.stdout
+            if opts.out_file then
+                return result
+            else
+                return result.stdout
+            end
         end)
 end
 
diff --git a/tests/core/fetch_spec.lua b/tests/core/fetch_spec.lua
index dac7c7b8..b4929167 100644
--- a/tests/core/fetch_spec.lua
+++ b/tests/core/fetch_spec.lua
@@ -29,6 +29,7 @@ describe("fetch", function()
             assert.spy(spawn.curl).was_called_with {
                 { "-H", "User-Agent: nvim-lsp-installer (+https://github.com/williamboman/nvim-lsp-installer)" },
                 "-fsSL",
+                vim.NIL,
                 "https://api.github.com",
             }
         end)
@@ -46,4 +47,33 @@ describe("fetch", function()
             assert.equals([[{"data": "here"}]], result:get_or_throw())
         end)
     )
+
+    it(
+        "should respect out_file opt",
+        async_test(function()
+            stub(spawn, "wget")
+            stub(spawn, "curl")
+            spawn.wget.returns(Result.failure "wget failure")
+            spawn.curl.returns(Result.failure "curl failure")
+            fetch("https://api.github.com/data", { out_file = "/test.json" })
+
+            assert.spy(spawn.wget).was_called_with {
+                {
+                    "--header",
+                    "User-Agent: nvim-lsp-installer (+https://github.com/williamboman/nvim-lsp-installer)",
+                },
+                "-nv",
+                "-O",
+                "/test.json",
+                "https://api.github.com/data",
+            }
+
+            assert.spy(spawn.curl).was_called_with {
+                { "-H", "User-Agent: nvim-lsp-installer (+https://github.com/williamboman/nvim-lsp-installer)" },
+                "-fsSL",
+                { "-o", "/test.json" },
+                "https://api.github.com/data",
+            }
+        end)
+    )
 end)