feat(diagnostic): revert default behaviour of goto_next/prev()

Follow-up to #28490

Problem:

The new behaviour of goto_next/prev() of navigating to the next highest
severity doesn't work well when diagnostic providers have different
interpretations of severities. E.g. the user may be blocked from
navigating to a useful LSP warning, due to some linter error.

Solution:

The behaviour of next highest severity is now a hidden option
`_highest = true`. We can revisit how to integrate this behaviour
during the 0.11 cycle.

runtime/doc/diagnostic.txt

@@ -389,9 +389,8 @@ Lua module: vim.diagnostic                                    *diagnostic-api*
                             |nvim_win_get_cursor()|.
       • {wrap}?             (`boolean`, default: `true`) Whether to loop
                             around file or not. Similar to 'wrapscan'.
-      • {severity}?         (`vim.diagnostic.Severity`) See
+      • {severity}?         (`vim.diagnostic.SeverityFilter`) See
-                            |diagnostic-severity|. If `nil`, go to the
+                            |diagnostic-severity|.
-                            diagnostic with the highest severity.
       • {float}?            (`boolean|vim.diagnostic.Opts.Float`, default:
                             `true`) If `true`, call
                             |vim.diagnostic.open_float()| after moving. If a
@@ -435,7 +434,7 @@ Lua module: vim.diagnostic                                    *diagnostic-api*
       • {update_in_insert}?  (`boolean`, default: `false`) Update diagnostics
                              in Insert mode (if `false`, diagnostics are
                              updated on |InsertLeave|)
-      • {severity_sort}?     (`boolean|{reverse?:boolean}`, default: `false)
+      • {severity_sort}?     (`boolean|{reverse?:boolean}`, default: `false`)
                              Sort diagnostics by severity. This affects the
                              order in which signs and virtual text are
                              displayed. When true, higher severities are

runtime/doc/news.txt

@@ -140,11 +140,6 @@ The following changes may require adaptations in user config or plugins.
 • |nvim_open_win()| now blocks all autocommands when `noautocmd` is set,
   rather than just those from setting the `buffer` to display in the window.
 
-• |vim.diagnostic.goto_next()| and |vim.diagnostic.goto_prev()| jump to the
-  diagnostic with the highest severity when the "severity" option is
-  unspecified. To use the old behavior, use: >lua
-    vim.diagnostic.goto_next({ severity = { min = vim.diagnostic.severity.HINT } })
-
 ==============================================================================
 BREAKING CHANGES IN HEAD                                    *news-breaking-dev*
 

runtime/lua/vim/diagnostic.lua

@@ -76,7 +76,7 @@ local M = {}
 --- before lower severities (e.g. ERROR is displayed before WARN).
 --- Options:
 ---   - {reverse}? (boolean) Reverse sort order
---- (default: `false)
+--- (default: `false`)
 --- @field severity_sort? boolean|{reverse?:boolean}
 
 --- @class (private) vim.diagnostic.OptsResolved
@@ -812,6 +812,29 @@ local function set_list(loclist, opts)
   end
 end
 
+--- Jump to the diagnostic with the highest severity. First sort the
+--- diagnostics by severity. The first diagnostic then contains the highest severity, and we can
+--- discard all diagnostics with a lower severity.
+--- @param diagnostics vim.Diagnostic[]
+local function filter_highest(diagnostics)
+  table.sort(diagnostics, function(a, b)
+    return a.severity < b.severity
+  end)
+
+  -- Find the first diagnostic where the severity does not match the highest severity, and remove
+  -- that element and all subsequent elements from the array
+  local worst = (diagnostics[1] or {}).severity
+  local len = #diagnostics
+  for i = 2, len do
+    if diagnostics[i].severity ~= worst then
+      for j = i, len do
+        diagnostics[j] = nil
+      end
+      break
+    end
+  end
+end
+
 --- @param position {[1]: integer, [2]: integer}
 --- @param search_forward boolean
 --- @param bufnr integer
@@ -823,29 +846,13 @@ local function next_diagnostic(position, search_forward, bufnr, opts, namespace)
   bufnr = get_bufnr(bufnr)
   local wrap = if_nil(opts.wrap, true)
 
-  local diagnostics =
+  local get_opts = vim.deepcopy(opts)
-    get_diagnostics(bufnr, vim.tbl_extend('keep', opts, { namespace = namespace }), true)
+  get_opts.namespace = get_opts.namespace or namespace
 
-  -- When severity is unset we jump to the diagnostic with the highest severity. First sort the
+  local diagnostics = get_diagnostics(bufnr, get_opts, true)
-  -- diagnostics by severity. The first diagnostic then contains the highest severity, and we can
-  -- discard all diagnostics with a lower severity.
-  if opts.severity == nil then
-    table.sort(diagnostics, function(a, b)
-      return a.severity < b.severity
-    end)
 
-    -- Find the first diagnostic where the severity does not match the highest severity, and remove
+  if opts._highest then
-    -- that element and all subsequent elements from the array
+    filter_highest(diagnostics)
-    local worst = (diagnostics[1] or {}).severity
-    local len = #diagnostics
-    for i = 2, len do
-      if diagnostics[i].severity ~= worst then
-        for j = i, len do
-          diagnostics[j] = nil
-        end
-        break
-      end
-    end
   end
 
   local line_diagnostics = diagnostic_lines(diagnostics)
@@ -1191,8 +1198,12 @@ end
 --- (default: `true`)
 --- @field wrap? boolean
 ---
---- See |diagnostic-severity|. If `nil`, go to the diagnostic with the highest severity.
+--- See |diagnostic-severity|.
---- @field severity? vim.diagnostic.Severity
+--- @field severity? vim.diagnostic.SeverityFilter
+---
+--- Go to the diagnostic with the highest severity.
+--- (default: `false`)
+--- @field package _highest? boolean
 ---
 --- If `true`, call |vim.diagnostic.open_float()| after moving.
 --- If a table, pass the table as the {opts} parameter to |vim.diagnostic.open_float()|.

test/functional/lua/diagnostic_spec.lua

@@ -962,7 +962,7 @@ describe('vim.diagnostic', function()
       eq(
         { 3, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next()
+        vim.diagnostic.goto_next({_highest = true})
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -970,7 +970,7 @@ describe('vim.diagnostic', function()
       eq(
         { 5, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next()
+        vim.diagnostic.goto_next({_highest = true})
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -991,7 +991,7 @@ describe('vim.diagnostic', function()
       eq(
         { 4, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next()
+        vim.diagnostic.goto_next({_highest = true})
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -999,7 +999,7 @@ describe('vim.diagnostic', function()
       eq(
         { 6, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next()
+        vim.diagnostic.goto_next({_highest = true})
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -1021,7 +1021,7 @@ describe('vim.diagnostic', function()
       eq(
         { 2, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next({ severity = { min = vim.diagnostic.severity.HINT } })
+        vim.diagnostic.goto_next()
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -1029,7 +1029,7 @@ describe('vim.diagnostic', function()
       eq(
         { 3, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next({ severity = { min = vim.diagnostic.severity.HINT } })
+        vim.diagnostic.goto_next()
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )
@@ -1037,7 +1037,7 @@ describe('vim.diagnostic', function()
       eq(
         { 4, 0 },
         exec_lua([[
-        vim.diagnostic.goto_next({ severity = { min = vim.diagnostic.severity.HINT } })
+        vim.diagnostic.goto_next()
         return vim.api.nvim_win_get_cursor(0)
       ]])
       )