loleaflet: introduce "stylelint" a modern linter for CSS

Change-Id: I8a7427eeb3b838baac8a6669d5313dc0d53d9ddd
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/102199
Tested-by: Pedro Silva <pedro.silva@collabora.com>
Reviewed-by: Pedro Silva <pedro.silva@collabora.com>

loleaflet/.gitignore

@@ -1,6 +1,5 @@
 node_modules
 node_cache
-.*
 tmp/**/*
 *.iml
 *.sublime-*

loleaflet/.stylelintrc.json

@@ -0,0 +1,13 @@
+{
+	"rules": {
+		"indentation": "tab",
+		"string-quotes": "single",
+		"no-duplicate-selectors": true,
+		"selector-combinator-space-after": "always",
+		"selector-attribute-quotes": "always",
+		"selector-attribute-brackets-space-inside": "never",
+		"function-url-quotes": ["always", {
+			"except": ["empty"]
+		}]
+	}
+}

loleaflet/Makefile.am

@@ -447,6 +447,8 @@ $(INTERMEDIATE_DIR)/loleaflet-src.js: $(call prereq_loleaflet)
 
 $(DIST_FOLDER)/bundle.css: $(call prereq_css)
 	@mkdir -p $(dir $@)
+	@echo "Checking for CSS errors..."
+	@$(NODE) node_modules/stylelint/bin/stylelint.js --config $(srcdir)/.stylelintrc.json $(srcdir)/css/*.css
 	$(call bundle_css)
 
 $(DIST_FOLDER)/bundle.js: $(INTERMEDIATE_DIR)/loleaflet-src.js $(call prereq_all)

loleaflet/package.json

@@ -23,7 +23,9 @@
     "uglifycss": "0.0.29",
     "uglifyify": "5.0.2",
     "vex-js": "4.1.0",
-    "typescript": "3.9.5"
+    "typescript": "3.9.5",
+    "stylelint-config-standard": "20.0.0",
+    "stylelint": "13.7.0"
   },
   "repository": {
     "type": "git",