feat(vim.version): add __eq to vim.VersionRange #38881

Problem: vim.VersionRange had no __eq metamethod, so comparing 2 distinct
but same value instances always returned false. In vim.pack.add this caused
redundant lockfile rewrites, even when the resulting lockfile content was
unchanged.

Solution: Add __eq metamethod on vim.VersionRange

runtime/doc/news.txt

@@ -65,6 +65,7 @@ LSP
 LUA
 
 • Renamed `vim.diff` to `vim.text.diff`.
+• Added `__eq` metamethod to |vim.VersionRange|.
 
 OPTIONS
 
@@ -301,6 +302,9 @@ LUA
 • EXPERIMENTAL: |vim.pos|, |vim.range| provide Position/Range abstraction.
 • |vim.filetype.inspect()| returns a copy of the internal tables used for
   filetype detection.
+• Added `__eq` metamethod to |vim.VersionRange|. 2 distinct but representing
+the same range instances now compare equal.
+
 
 OPTIONS
 

runtime/lua/vim/version.lua

@@ -273,6 +273,9 @@ end
 
 local range_mt = {
   __index = VersionRange,
+  __eq = function(self, other)
+    return self.to == other.to and self.from == other.from
+  end,
   __tostring = function(self)
     if not self.to then
       return '>=' .. tostring(self.from)

test/functional/lua/version_spec.lua

@@ -118,6 +118,18 @@ describe('version', function()
       end)
     end
 
+    it('__eq', function()
+      local range1 = vim.version.range('1.2.3 - 2.3.4')
+      local range2 = vim.version.range('1.2.3 - 2.3.4')
+      local range3 = vim.version.range('<=1.2.3')
+      local range4 = vim.version.range('1.2.3')
+      assert(range1 == range1)
+      assert(range1 == range2)
+      assert(range1 ~= range3)
+      assert(range1 ~= range4)
+      assert(range3 ~= range4)
+    end)
+
     it('handles prerelease', function()
       assert(not vim.version.range('1.2.3'):has('1.2.3-alpha'))
       assert(vim.version.range('1.2.3-alpha'):has('1.2.3-alpha'))