refactor(diagnostic): remove bufnr parameter from open_float (#16579)

The overwhelming majority of use cases for `open_float` are to view
diagnostics from the current buffer in a floating window. Thus, most use
cases will just `0` or `nil` as the first argument, which makes the
argument effectively useless and wasteful.

In the cause of optimizing for the primary use case, make the `bufnr`
parameter an optional parameter in the options table. This still allows
using an alternative buffer for those that wish to do so, but makes the
"primary" use case much easier.

The old signature is preserved for backward compatibility, though it can
likely be fully deprecated at some point.

1 files changed, 27 insertions, 13 deletions

diff --git a/test/functional/lua/diagnostic_spec.lua b/test/functional/lua/diagnostic_spec.lua
index eeb9316b06..a88da63e90 100644
--- a/test/functional/lua/diagnostic_spec.lua
+++ b/test/functional/lua/diagnostic_spec.lua
@@ -1343,7 +1343,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header = "We're no strangers to love..."})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = "We're no strangers to love..."})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1355,7 +1355,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header = {'You know the rules', 'Search'}})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = {'You know the rules', 'Search'}})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1370,7 +1370,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header = false, scope="buffer"})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope="buffer"})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1387,7 +1387,7 @@ describe('vim.diagnostic', function()
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
         vim.api.nvim_win_set_cursor(0, {2, 1})
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header=false})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header=false})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1402,7 +1402,7 @@ describe('vim.diagnostic', function()
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
         vim.api.nvim_win_set_cursor(0, {1, 1})
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header=false, pos=1})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header=false, pos=1})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1419,7 +1419,7 @@ describe('vim.diagnostic', function()
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
         vim.api.nvim_win_set_cursor(0, {2, 2})
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header=false, scope="cursor"})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header=false, scope="cursor"})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1434,7 +1434,7 @@ describe('vim.diagnostic', function()
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
         vim.api.nvim_win_set_cursor(0, {1, 1})
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header=false, scope="cursor", pos={1,3}})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header=false, scope="cursor", pos={1,3}})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1449,7 +1449,7 @@ describe('vim.diagnostic', function()
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
         vim.api.nvim_win_set_cursor(0, {1, 1})
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header=false, scope="cursor", pos={0,first_line_len}})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header=false, scope="cursor", pos={0,first_line_len}})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1665,7 +1665,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header = false, scope = "buffer"})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope = "buffer"})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1678,7 +1678,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {header = false, scope = "buffer", prefix = ""})
+        local float_bufnr, winnr = vim.diagnostic.open_float({header = false, scope = "buffer", prefix = ""})
         local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
         vim.api.nvim_win_close(winnr, true)
         return lines
@@ -1691,7 +1691,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {
+        local float_bufnr, winnr = vim.diagnostic.open_float({
           header = false,
           prefix = function(_, i, total)
             -- Only show a number if there is more than one diagnostic
@@ -1712,7 +1712,7 @@ describe('vim.diagnostic', function()
         }
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
         vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
-        local float_bufnr, winnr = vim.diagnostic.open_float(0, {
+        local float_bufnr, winnr = vim.diagnostic.open_float({
           header = false,
           prefix = function(_, i, total)
             -- Only show a number if there is more than one diagnostic
@@ -1728,7 +1728,21 @@ describe('vim.diagnostic', function()
       ]])
 
       eq("Error executing lua: .../diagnostic.lua:0: prefix: expected 'string' or 'table' or 'function', got 42",
-        pcall_err(exec_lua, [[ vim.diagnostic.open_float(0, { prefix = 42 }) ]]))
+        pcall_err(exec_lua, [[ vim.diagnostic.open_float({ prefix = 42 }) ]]))
+    end)
+
+    it('works with the old signature', function()
+      eq({'1. Syntax error'}, exec_lua [[
+        local diagnostics = {
+          make_error("Syntax error", 0, 1, 0, 3),
+        }
+        vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, diagnostics)
+        local float_bufnr, winnr = vim.diagnostic.open_float(0, { header = false })
+        local lines = vim.api.nvim_buf_get_lines(float_bufnr, 0, -1, false)
+        vim.api.nvim_win_close(winnr, true)
+        return lines
+      ]])
     end)
   end)