From c475091eeba684459dfb9412fa8b782dfc997d26 Mon Sep 17 00:00:00 2001
From: connorgmeean <a@cgm.codes>
Date: Thu, 8 Sep 2022 12:56:39 +1000
Subject: [PATCH] feat(core): Add `requires_modules` field to modules

Allow devs to specify module dependencies and throw an error / safely disable that a module if the dependency is not enabled.
I.e. extra_snippets depends on lsp and will print an error if `lsp` is not enabled.
---
 lua/doom/core/modules.lua                     | 78 ++++++++++++-------
 .../modules/features/extra_snippets/init.lua  |  1 +
 lua/doom/modules/features/linter/init.lua     |  2 +
 lua/doom/modules/features/projects/init.lua   |  2 +
 4 files changed, 57 insertions(+), 26 deletions(-)

diff --git a/lua/doom/core/modules.lua b/lua/doom/core/modules.lua
index 4312ced36..afa447775 100644
--- a/lua/doom/core/modules.lua
+++ b/lua/doom/core/modules.lua
@@ -113,42 +113,68 @@ local keymaps_service = require("doom.services.keymaps")
 --- Applies commands, autocommands, packages from enabled modules (`modules.lua`).
 modules.load_modules = function()
   local use = require("packer").use
+  local logger = require("doom.utils.logging")
   -- Handle the Modules
   for section_name, _ in pairs(doom.modules) do
-    for module_name, module in pairs(doom[section_name]) do
-      -- Import dependencies with packer from module.packages
-      if module.packages then
-        for dependency_name, packer_spec in pairs(module.packages) do
-          -- Set packer_spec to configure function
-          if module.configs and module.configs[dependency_name] then
-            packer_spec.config = module.configs[dependency_name]
+    for module_name, module in pairs(doom.modules[section_name]) do
+      -- Flag to continue enabling module
+      local should_enable_module = true
+
+      -- Check module has necessary dependencies
+      if module.requires_modules then
+        for _, dependent_module in ipairs(module.requires_modules) do
+          local dep_section_name, dep_module_name = unpack(vim.split(dependent_module, "%."))
+
+          if not doom.modules[dep_section_name][dep_module_name] then
+            should_enable_module = false
+            logger.error(
+              ("Doom module \"%s.%s\" depends on a module that is not enabled \"%s.%s\".  Please enable the %s module."):format(
+                section_name,
+                module_name,
+                dep_section_name,
+                dep_module_name,
+                dep_module_name
+              )
+            )
           end
+        end
+      end
+
+      if should_enable_module then
+        -- Import dependencies with packer from module.packages
+        if module.packages then
+          for dependency_name, packer_spec in pairs(module.packages) do
+            -- Set packer_spec to configure function
+            if module.configs and module.configs[dependency_name] then
+              packer_spec.config = module.configs[dependency_name]
+            end
 
-          -- Set/unset frozen packer dependencies
-          packer_spec.commit = doom.freeze_dependencies and packer_spec.commit or nil
+            -- Set/unset frozen packer dependencies
+            packer_spec.commit = doom.freeze_dependencies and packer_spec.commit or nil
 
-          -- Initialise packer
-          use(packer_spec)
+            -- Initialise packer
+            use(packer_spec)
+          end
         end
-      end
 
-      -- Setup package autogroups
-      if module.autocmds then
-        local autocmds = type(module.autocmds) == "function" and module.autocmds()
-          or module.autocmds
-        utils.make_augroup(module_name, autocmds)
-      end
+        -- Setup package autogroups
+        if module.autocmds then
+          local autocmds = type(module.autocmds) == "function" and module.autocmds()
+            or module.autocmds
+          utils.make_augroup(module_name, autocmds)
+        end
 
-      if module.cmds then
-        for _, cmd_spec in ipairs(module.cmds) do
-          utils.make_cmd(cmd_spec[1], cmd_spec[2])
+        if module.cmds then
+          for _, cmd_spec in ipairs(module.cmds) do
+            utils.make_cmd(cmd_spec[1], cmd_spec[2])
+          end
         end
-      end
 
-      if module.binds then
-        keymaps_service.applyKeymaps(
-          type(module.binds) == "function" and module.binds() or module.binds
-        )
+        if module.binds then
+          keymaps_service.applyKeymaps(
+            type(module.binds) == "function" and module.binds() or module.binds
+          )
+        end
       end
     end
   end
diff --git a/lua/doom/modules/features/extra_snippets/init.lua b/lua/doom/modules/features/extra_snippets/init.lua
index 5ba6bac6a..b52751b50 100644
--- a/lua/doom/modules/features/extra_snippets/init.lua
+++ b/lua/doom/modules/features/extra_snippets/init.lua
@@ -9,6 +9,7 @@ extra_snippets.packages = {
   },
 }
 
+extra_snippets.requires_modules = { "features.lsp" }
 extra_snippets.configs = {}
 extra_snippets.configs["friendly-snippets"] = function()
   require("luasnip.loaders.from_vscode").lazy_load()
diff --git a/lua/doom/modules/features/linter/init.lua b/lua/doom/modules/features/linter/init.lua
index da6c1e1bf..0a2a7ab0e 100644
--- a/lua/doom/modules/features/linter/init.lua
+++ b/lua/doom/modules/features/linter/init.lua
@@ -7,6 +7,8 @@ linter.settings = {
   },
 }
 
+linter.requires_modules = { "features.lsp" }
+
 linter.packages = {
   ["null-ls.nvim"] = {
     "jose-elias-alvarez/null-ls.nvim",
diff --git a/lua/doom/modules/features/projects/init.lua b/lua/doom/modules/features/projects/init.lua
index 5b72460df..704ed8423 100644
--- a/lua/doom/modules/features/projects/init.lua
+++ b/lua/doom/modules/features/projects/init.lua
@@ -43,6 +43,8 @@ projects.packages = {
   },
 }
 
+projects.requires_modules = { "features.telescope" }
+
 projects.configs = {}
 projects.configs["project.nvim"] = function()
   require("project_nvim").setup(doom.features.projects.settings)