better error messaging

1 files changed, 47 insertions, 30 deletions

diff --git a/lua/nvim-lsp-installer/installers/context.lua b/lua/nvim-lsp-installer/installers/context.lua
index 2f56e25c..20097915 100644
--- a/lua/nvim-lsp-installer/installers/context.lua
+++ b/lua/nvim-lsp-installer/installers/context.lua
@@ -7,17 +7,22 @@ local M = {}
 
 local function fetch(url, callback)
     local stdio = process.in_memory_sink()
+    log.fmt_debug("Fetching URL %s", url)
+    local on_exit = function(success)
+        if success then
+            log.fmt_debug("Successfully fetched URL %s", url)
+            callback(nil, table.concat(stdio.buffers.stdout, ""))
+        else
+            local stderr = table.concat(stdio.buffers.stderr, "")
+            log.fmt_warn("Failed to fetch URL %s. stderr=%s", url, stderr)
+            callback(("Failed to fetch url %q.\n%s"):format(url, stderr), nil)
+        end
+    end
     if platform.is_unix then
         process.spawn("wget", {
             args = { "-nv", "-O", "-", url },
             stdio_sink = stdio.sink,
-        }, function(success)
-            if success then
-                callback(nil, table.concat(stdio.buffers.stdout, ""))
-            else
-                callback(("Failed to fetch url=%s"):format(url), nil)
-            end
-        end)
+        }, on_exit)
     elseif platform.is_win then
         local script = {
             "$ProgressPreference = 'SilentlyContinue'",
@@ -26,30 +31,39 @@ local function fetch(url, callback)
         process.spawn("powershell.exe", {
             args = { "-Command", table.concat(script, ";") },
             stdio_sink = stdio.sink,
-        }, function(success)
-            if success then
-                callback(nil, table.concat(stdio.buffers.stdout, ""))
-            else
-                callback(("Failed to fetch url=%s"):format(url), nil)
-            end
-        end)
+        }, on_exit)
     else
         error "Unexpected error: Unsupported OS."
     end
 end
 
 function M.github_release_file(repo, file)
-    local function get_download_url(version)
-        return ("https://github.com/%s/releases/download/%s/%s"):format(
-            repo,
-            version,
-            type(file) == "function" and file(version) or file
-        )
-    end
-
     return function(server, callback, context)
+        local function get_download_url(version)
+            local target_file = type(file) == "function" and file(version) or file
+            if not target_file then
+                log.fmt_error(
+                    "Unable to find which release file to download. server_name=%s, repo=%s",
+                    server.name,
+                    repo
+                )
+                context.stdio_sink.stderr(
+                    (
+                        "Could not find which release file to download. Most likely, the current operating system or architecture (%s) is not supported.\n"
+                    ):format(platform.arch)
+                )
+                return nil
+            end
+
+            return ("https://github.com/%s/releases/download/%s/%s"):format(repo, version, target_file)
+        end
         if context.requested_server_version then
-            context.github_release_file = get_download_url(context.requested_server_version)
+            -- User has already provided a version - don't fetch the latest version from GitHub
+            local download_url = get_download_url(context.requested_server_version)
+            if not download_url then
+                return callback(false)
+            end
+            context.github_release_file = download_url
             callback(true)
         else
             context.stdio_sink.stdout "Fetching latest release version from GitHub API...\n"
@@ -57,15 +71,18 @@ function M.github_release_file(repo, file)
                 ("https://api.github.com/repos/%s/releases/latest"):format(repo),
                 vim.schedule_wrap(function(err, response)
                     if err then
-                        context.stdio_sink.stderr "Failed to fetch latest release version from GitHub API.\n"
+                        context.stdio_sink.stderr(tostring(err))
+                        return callback(false)
+                    end
+                    local version = Data.json_decode(response).tag_name
+                    log.debug("Resolved latest version", server.name, version)
+                    context.requested_server_version = version
+                    local download_url = get_download_url(version)
+                    if not download_url then
                         return callback(false)
-                    else
-                        local version = Data.json_decode(response).tag_name
-                        log.debug("Resolved latest version", server.name, version)
-                        context.requested_server_version = version
-                        context.github_release_file = get_download_url(version)
-                        callback(true)
                     end
+                    context.github_release_file = download_url
+                    callback(true)
                 end)
             )
         end