feat(diagnostic): add enabled filter (#33981)

runtime/doc/diagnostic.txt

@@ -440,6 +440,9 @@ Lua module: vim.diagnostic                                    *diagnostic-api*
                       specified line number.
       • {severity}?   (`vim.diagnostic.SeverityFilter`) See
                       |diagnostic-severity|.
+      • {enabled}?    (`boolean`, default: `nil`) Limit diagnostics to only
+                      enabled or disabled. If nil, enablement is ignored. See
+                      |vim.diagnostic.enable()|
 
 *vim.diagnostic.JumpOpts*
     Extends: |vim.diagnostic.GetOpts|

runtime/doc/news.txt

@@ -129,6 +129,8 @@ DIAGNOSTICS
 • |vim.diagnostic.setloclist()| and |vim.diagnostic.setqflist()| now support a
   `format` function to modify (or filter) diagnostics before being set in the
   location/quickfix list.
+• |vim.diagnostic.get()| now accepts an `enabled` filter to only return
+  enabled or disabled diagnostics.
 
 EDITOR
 

runtime/lua/vim/diagnostic.lua

@@ -832,11 +832,24 @@ local function get_diagnostics(bufnr, opts, clamp)
       return true
     end
 
+  ---@param b integer
+  ---@param d vim.Diagnostic
+  local match_enablement = function(d, b)
+    if opts.enabled == nil then
+      return true
+    end
+
+    local enabled = M.is_enabled({ bufnr = b, ns_id = d.namespace })
+
+    return (enabled and opts.enabled) or (not enabled and not opts.enabled)
+  end
+
   ---@param b integer
   ---@param d vim.Diagnostic
   local function add(b, d)
     if
       match_severity(d)
+      and match_enablement(d, b)
       and (not opts.lnum or (opts.lnum >= d.lnum and opts.lnum <= (d.end_lnum or d.lnum)))
     then
       if clamp and api.nvim_buf_is_loaded(b) then
@@ -1345,6 +1358,11 @@ end
 ---
 --- See |diagnostic-severity|.
 --- @field severity? vim.diagnostic.SeverityFilter
+---
+--- Limit diagnostics to only enabled or disabled. If nil, enablement is ignored.
+--- See |vim.diagnostic.enable()|
+--- (default: `nil`)
+--- @field enabled? boolean
 
 --- Configuration table with the keys listed below. Some parameters can have their default values
 --- changed with |vim.diagnostic.config()|.

test/functional/lua/diagnostic_spec.lua

@@ -1531,6 +1531,29 @@ describe('vim.diagnostic', function()
         end)
       )
     end)
+
+    it('allows filtering by enablement', function()
+      eq(
+        { 3, 1, 2 },
+        exec_lua(function()
+          vim.diagnostic.set(_G.diagnostic_ns, _G.diagnostic_bufnr, {
+            _G.make_error('Error 1', 1, 1, 1, 5),
+          })
+          vim.diagnostic.set(_G.other_ns, _G.diagnostic_bufnr, {
+            _G.make_error('Error 2', 1, 1, 1, 5),
+            _G.make_error('Error 3', 3, 1, 3, 5),
+          })
+
+          vim.diagnostic.enable(false, { ns_id = _G.other_ns })
+
+          return {
+            #vim.diagnostic.get(_G.diagnostic_bufnr),
+            #vim.diagnostic.get(_G.diagnostic_bufnr, { enabled = true }),
+            #vim.diagnostic.get(_G.diagnostic_bufnr, { enabled = false }),
+          }
+        end)
+      )
+    end)
   end)
 
   describe('count', function()