add-erlangls (#144)

Co-authored-by: William Boman <william@redwill.se>

4 files changed, 75 insertions, 31 deletions

diff --git a/README.md b/README.md
index 902e8a18..0239d90e 100644
--- a/README.md
+++ b/README.md
@@ -140,6 +140,7 @@ require("nvim-lsp-installer").settings {
 | Elm                                 | `elmls`                  |
 | Ember                               | `ember`                  |
 | Emmet                               | `emmet_ls`               |
+| Erlang                              | `erlangls`              |
 | Fortran                             | `fortls`                 |
 | Go                                  | `gopls`                  |
 | GraphQL                             | `graphql`                |
diff --git a/lua/nvim-lsp-installer/installers/context.lua b/lua/nvim-lsp-installer/installers/context.lua
index e75f089d..3e36b6b5 100644
--- a/lua/nvim-lsp-installer/installers/context.lua
+++ b/lua/nvim-lsp-installer/installers/context.lua
@@ -1,6 +1,7 @@
 local Data = require "nvim-lsp-installer.data"
 local log = require "nvim-lsp-installer.log"
 local process = require "nvim-lsp-installer.process"
+local installers = require "nvim-lsp-installer.installers"
 local platform = require "nvim-lsp-installer.platform"
 
 local M = {}
@@ -56,34 +57,12 @@ local function fetch(url, callback)
     }
 end
 
-function M.github_release_file(repo, file)
+function M.latest_github_release(repo)
     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
+        context.github_repo = repo
         if context.requested_server_version then
             -- 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)
+            return callback(true)
         else
             context.stdio_sink.stdout "Fetching latest release version from GitHub API...\n"
             fetch(
@@ -94,13 +73,8 @@ function M.github_release_file(repo, file)
                         return callback(false)
                     end
                     local version = Data.json_decode(response).tag_name
-                    log.debug("Resolved latest version", server.name, version)
+                    log.debug("Resolved latest version", server.name, repo, version)
                     context.requested_server_version = version
-                    local download_url = get_download_url(version)
-                    if not download_url then
-                        return callback(false)
-                    end
-                    context.github_release_file = download_url
                     callback(true)
                 end)
             )
@@ -108,6 +82,39 @@ function M.github_release_file(repo, file)
     end
 end
 
+function M.github_release_file(repo, file)
+    return installers.pipe {
+        M.latest_github_release(repo),
+        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
+
+            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)
+        end,
+    }
+end
+
 function M.capture(fn)
     return function(server, callback, context, ...)
         local installer = fn(context)
diff --git a/lua/nvim-lsp-installer/servers/erlangls/init.lua b/lua/nvim-lsp-installer/servers/erlangls/init.lua
new file mode 100644
index 00000000..4baa075a
--- /dev/null
+++ b/lua/nvim-lsp-installer/servers/erlangls/init.lua
@@ -0,0 +1,35 @@
+local server = require "nvim-lsp-installer.server"
+local path = require "nvim-lsp-installer.path"
+local process = require "nvim-lsp-installer.process"
+local std = require "nvim-lsp-installer.installers.std"
+local context = require "nvim-lsp-installer.installers.context"
+local platform = require "nvim-lsp-installer.platform"
+
+return function(name, root_dir)
+    local erlang_ls_file_ext = platform.is_win and ".cmd" or ""
+    return server.Server:new {
+        name = name,
+        root_dir = root_dir,
+        homepage = "https://erlang-ls.github.io/",
+        installer = {
+            std.ensure_executables {
+                { "rebar3", "rebar3 was not found in path. Refer to http://rebar3.org/docs/." },
+            },
+            context.latest_github_release "erlang-ls/erlang_ls",
+            std.git_clone "https://github.com/erlang-ls/erlang_ls.git",
+            function(server, callback, context)
+                local c = process.chain {
+                    cwd = server.root_dir,
+                    stdio_sink = context.stdio_sink,
+                }
+                local rebar3 = platform.is_win and "rebar3.cmd" or "rebar3"
+                c.run(rebar3, { "escriptize" })
+                c.run(rebar3, { "as", "dap", "escriptize" })
+                c.spawn(callback)
+            end,
+        },
+        default_options = {
+            cmd = { path.concat { root_dir, "_build", "default", "bin", ("erlang_ls%s"):format(erlang_ls_file_ext) } },
+        },
+    }
+end
diff --git a/lua/nvim-lsp-installer/servers/init.lua b/lua/nvim-lsp-installer/servers/init.lua
index 48516442..35c23627 100644
--- a/lua/nvim-lsp-installer/servers/init.lua
+++ b/lua/nvim-lsp-installer/servers/init.lua
@@ -56,6 +56,7 @@ local CORE_SERVERS = Data.set_of {
     "elmls",
     "ember",
     "emmet_ls",
+    "erlangls",
     "eslintls",
     "fortls",
     "gopls",