fix(gem): write shim executables that enhance GEM_PATH appropriately (#202)

2 files changed, 52 insertions, 34 deletions

diff --git a/lua/mason-core/installer/context.lua b/lua/mason-core/installer/context.lua
index a3577cfa..93d45a8a 100644
--- a/lua/mason-core/installer/context.lua
+++ b/lua/mason-core/installer/context.lua
@@ -226,29 +226,42 @@ end
 
 ---@param new_executable_rel_path string: Relative path to the executable file to create.
 ---@param command string: The shell command to run.
+---@param env table<string, string>?
 ---@return string: The created executable filename.
-function InstallContext:write_shell_exec_wrapper(new_executable_rel_path, command)
+function InstallContext:write_shell_exec_wrapper(new_executable_rel_path, command, env)
     return platform.when {
         unix = function()
             local std = require "mason-core.managers.std"
+            local formatted_envs = _.map(function(pair)
+                local var, value = pair[1], pair[2]
+                return ("export %s=%q"):format(var, value)
+            end, _.to_pairs(env or {}))
+
             self.fs:write_file(
                 new_executable_rel_path,
                 _.dedent(([[
                     #!/bin/bash
+                    %s
                     exec %s "$@"
-                ]]):format(command))
+                ]]):format(_.join("\n", formatted_envs), command))
             )
             std.chmod("+x", { new_executable_rel_path })
             return new_executable_rel_path
         end,
         win = function()
             local executable_file = ("%s.cmd"):format(new_executable_rel_path)
+            local formatted_envs = _.map(function(pair)
+                local var, value = pair[1], pair[2]
+                return ("SET %s=%s"):format(var, value)
+            end, _.to_pairs(env or {}))
+
             self.fs:write_file(
                 executable_file,
                 _.dedent(([[
                     @ECHO off
+                    %s
                     %s %%*
-                ]]):format(command))
+                ]]):format(_.join("\n", formatted_envs), command))
             )
             return executable_file
         end,
@@ -259,20 +272,4 @@ function InstallContext:link_bin(executable, rel_path)
     self.receipt:with_link("bin", executable, rel_path)
 end
 
----@param patches string[]
-function InstallContext:apply_patches(patches)
-    for _, patch in ipairs(patches) do
-        self.spawn.patch {
-            "-g",
-            "0",
-            "-f",
-            on_spawn = function(_, stdio)
-                local stdin = stdio[1]
-                stdin:write(patch)
-                stdin:close()
-            end,
-        }
-    end
-end
-
 return InstallContext
diff --git a/lua/mason-core/managers/gem/init.lua b/lua/mason-core/managers/gem/init.lua
index 8b64d68a..da9b800b 100644
--- a/lua/mason-core/managers/gem/init.lua
+++ b/lua/mason-core/managers/gem/init.lua
@@ -9,9 +9,38 @@ local platform = require "mason-core.platform"
 
 local M = {}
 
+---@param install_dir string
+local function env(install_dir)
+    return {
+        GEM_HOME = install_dir,
+        GEM_PATH = install_dir,
+        PATH = process.extend_path { path.concat { install_dir, "bin" } },
+    }
+end
+
 local create_bin_path = _.compose(path.concat, function(executable)
     return _.append(executable, { "bin" })
-end, _.if_else(_.always(platform.is.win), _.format "%s.cmd", _.identity))
+end, _.if_else(_.always(platform.is.win), _.format "%s.bat", _.identity))
+
+---@async
+---@param executable string
+local function link_executable(executable)
+    local ctx = installer.context()
+    local bin_path = create_bin_path(executable)
+    ctx:link_bin(
+        executable,
+        ctx:write_shell_exec_wrapper(executable, path.concat { ctx.package:get_install_path(), bin_path }, {
+            GEM_PATH = platform.when {
+                unix = function()
+                    return ("%s:$GEM_PATH"):format(ctx.package:get_install_path())
+                end,
+                win = function()
+                    return ("%s;%%GEM_PATH%%"):format(ctx.package:get_install_path())
+                end,
+            },
+        })
+    )
+end
 
 ---@param packages string[]
 local function with_receipt(packages)
@@ -49,12 +78,13 @@ function M.install(packages)
         "--bindir=bin",
         "--no-document",
         pkgs,
+        env = {
+            GEM_HOME = ctx.cwd:get(),
+        },
     }
 
     if packages.bin then
-        _.each(function(executable)
-            ctx:link_bin(executable, create_bin_path(executable))
-        end, packages.bin)
+        _.each(link_executable, packages.bin)
     end
 
     return {
@@ -109,7 +139,7 @@ function M.check_outdated_primary_package(receipt, install_dir)
     if receipt.primary_source.type ~= "gem" then
         return Result.failure "Receipt does not have a primary source of type gem"
     end
-    return spawn.gem({ "outdated", cwd = install_dir, env = M.env(install_dir) }):map_catching(function(result)
+    return spawn.gem({ "outdated", cwd = install_dir, env = env(install_dir) }):map_catching(function(result)
         ---@type string[]
         local lines = vim.split(result.stdout, "\n")
         local outdated_gems = vim.tbl_map(M.parse_outdated_gem, vim.tbl_filter(not_empty, lines))
@@ -138,7 +168,7 @@ function M.get_installed_primary_package_version(receipt, install_dir)
         .gem({
             "list",
             cwd = install_dir,
-            env = M.env(install_dir),
+            env = env(install_dir),
         })
         :map_catching(function(result)
             local gems = M.parse_gem_list_output(result.stdout)
@@ -147,13 +177,4 @@ function M.get_installed_primary_package_version(receipt, install_dir)
         end)
 end
 
----@param install_dir string
-function M.env(install_dir)
-    return {
-        GEM_HOME = install_dir,
-        GEM_PATH = install_dir,
-        PATH = process.extend_path { path.concat { install_dir, "bin" } },
-    }
-end
-
 return M