feat(LSP-Snippets): add basic support for scope field

DOC.md

@@ -1932,7 +1932,29 @@ Alternatively, `jsregexp` can be cloned locally, `make`d, and the resulting
 
 If `jsregexp` is not available, transformations are replaced by a simple copy.
 
-# Variables
+## VSCode snippet extra fields
+<!-- Works only in github -->
+> **Note** See also this [Issue 705] for more info
+```json 
+
+    {
+        "prefix": ...
+        "scope": "javascript,typescript",
+        "body": ...
+    }
+``` 
+The [`"scope": `](https://code.visualstudio.com/docs/editor/userdefinedsnippets#_snippet-scope)
+field is honored when loaded into the LuaSnip engine.
+If it isn't part of the current buffer (editor) language, then it's not imported.
+Let's say you have `shared.json` that has snippets for different languages specified via `scope`.
+When specific language mapped to a `.code-snippets` (or `.json`) file by a `package.json`
+then only snippets `scope`-ed to the same language are loaded. The rest is ignored.
+
+`"isFileTemplate" :` field isn't handled in anyway.
+
+[Issue 705]: https://github.com/L3MON4D3/LuaSnip/issues/705
+
+# VARIABLES
 
 All `TM_something`-variables are supported with two additions:
 `LS_SELECT_RAW` and `LS_SELECT_DEDENT`. These were introduced because

lua/luasnip/loaders/from_vscode.lua

@@ -37,7 +37,7 @@ local function read_json(fname)
 	end
 end
 
-local function get_file_snippets(file)
+local function get_file_snippets(lang, file)
 	local lang_snips = {}
 	local auto_lang_snips = {}
 
@@ -51,6 +51,14 @@ local function get_file_snippets(file)
 		local body = type(parts.body) == "string" and parts.body
 			or table.concat(parts.body, "\n")
 
+			-- Skip entire snippet if entry has `scope` field mismatching lang
+			-- This prevents snippets mapped by package.json to one language
+			-- to be used for another. This is not part of LSP Snippets! See:
+			-- https://code.visualstudio.com/docs/editor/userdefinedsnippets#_snippet-scope
+			if type(parts.scope) == "string" and not (string.match(parts.scope, lang)) then
+				goto continue
+			end
+
 		-- There are still some snippets that fail while loading
 		pcall(function()
 			-- Sometimes it's a list of prefixes instead of a single one
@@ -74,6 +82,8 @@ local function get_file_snippets(file)
 				end
 			end
 		end)
+
+		::continue::
 	end
 
 	return lang_snips, auto_lang_snips
@@ -90,7 +100,7 @@ local function load_snippet_files(lang, files, add_opts)
 				auto_lang_snips = vim.deepcopy(cached_path.autosnippets)
 				cached_path.fts[lang] = true
 			else
-				lang_snips, auto_lang_snips = get_file_snippets(file)
+				lang_snips, auto_lang_snips = get_file_snippets(lang, file)
 				-- store snippets to prevent parsing the same file more than once.
 				cache.path_snippets[file] = {
 					snippets = vim.deepcopy(lang_snips),
@@ -99,7 +109,6 @@ local function load_snippet_files(lang, files, add_opts)
 					fts = { [lang] = true },
 				}
 			end
-
 			ls.add_snippets(
 				lang,
 				lang_snips,
@@ -286,7 +295,6 @@ function M.lazy_load(opts)
 
 	local ft_files = get_snippet_files(opts)
 	local add_opts = loader_util.add_opts(opts)
-
 	loader_util.extend_ft_paths(cache.ft_paths, ft_files)
 
 	-- immediately load filetypes that have already been loaded.