refactor: address emmylua diagnostics

lua/linter.lua

@@ -46,7 +46,7 @@ local util = require("util")
 ---@field pattern? string
 --- Named capture groups for pattern matching (required if not using json)
 ---@field groups? ow.lsp.linter.Group[]
---- Map severity strings to vim diagnostic levels
+--- Map severity strings to vim diagnostic levels (required if not using json)
 ---@field severity_map? table<string, vim.diagnostic.Severity>
 --- Source name for diagnostics (default: command name)
 ---@field source? string
@@ -131,17 +131,13 @@ function Linter:add_tags(diag)
         return
     end
 
-    local have_unnecessary = vim.islist(self.config.tags.unnecessary)
-    local have_deprecated = vim.islist(self.config.tags.deprecated)
-
-    if not have_unnecessary and not have_deprecated then
-        return
-    end
-
-    diag._tags = {}
+    diag._tags = {
+        unnecessary = false,
+        deprecated = false,
+    }
 
     if
-        have_unnecessary
+        self.config.tags.unnecessary
         and vim.list_contains(self.config.tags.unnecessary, diag.code)
     then
         diag._tags.unnecessary = true
@@ -149,7 +145,7 @@ function Linter:add_tags(diag)
     end
 
     if
-        have_deprecated
+        self.config.tags.deprecated
         and vim.list_contains(self.config.tags.deprecated, diag.code)
     then
         diag._tags.deprecated = true
@@ -181,13 +177,15 @@ function Linter:fix_indexing(diag)
     end
 end
 
+---@param json any
 function Linter:process_json_output(json)
     ---@type vim.Diagnostic[]
     local diagnostics = {}
+    local cfg = assert(self.config.json)
 
     local items = json
-    if self.config.json.diagnostics_root then
-        items = Linter.get_json_value(json, self.config.json.diagnostics_root)
+    if cfg.diagnostics_root then
+        items = Linter.get_json_value(json, cfg.diagnostics_root)
     end
 
     if type(items) ~= "table" then
@@ -202,8 +200,9 @@ function Linter:process_json_output(json)
     for _, item in ipairs(items) do
         local diag = {}
 
-        for field, path in pairs(self.config.json) do
+        for field, path in pairs(cfg) do
             if field ~= "diagnostics_root" and field ~= "callback" then
+                ---@cast path string
                 diag[field] = Linter.get_json_value(item, path)
             end
         end
@@ -218,12 +217,14 @@ function Linter:process_json_output(json)
             diag.severity = self.config.severity_map[diag.severity]
         end
 
+        ---@cast diag vim.Diagnostic
+
         self:fix_indexing(diag)
         self:clamp_col(diag)
         self:add_tags(diag)
 
-        if type(self.config.json.callback) == "function" then
-            self.config.json.callback(diag)
+        if type(cfg.callback) == "function" then
+            cfg.callback(diag)
         end
 
         table.insert(diagnostics, diag)
@@ -371,6 +372,9 @@ function Linter:run()
 
                 return
             end
+            ---@cast self.config.pattern -nil
+            ---@cast self.config.groups -nil
+            ---@cast self.config.severity_map -nil
 
             local diagnostics = {}
             for _, line in ipairs(lines) do
@@ -387,6 +391,7 @@ function Linter:run()
                     success = false
                     return
                 elseif resp then
+                    ---@cast resp vim.Diagnostic
                     resp.source = resp.source or self.config.source
                     self:clamp_col(resp)
                     self:add_tags(resp)
@@ -439,7 +444,7 @@ function Linter.add(bufnr, config)
         buffer = linter.bufnr,
         callback = util.debounce(function()
             linter:run()
-        end, config.debounce) --[[@as fun()]],
+        end, config.debounce),
         group = linter.augroup,
     })