JS: Added support for keywords after a spread operator (#2148)

This PR fixes that keywords after a spread operator weren't highlighted. This is mainly for the `await` and `new` keywords.

components/prism-javascript.js

@@ -12,7 +12,7 @@ Prism.languages.javascript = Prism.languages.extend('clike', {
 			lookbehind: true
 		},
 		{
-			pattern: /(^|[^.])\b(?:as|async(?=\s*(?:function\b|\(|[$\w\xA0-\uFFFF]|$))|await|break|case|class|const|continue|debugger|default|delete|do|else|enum|export|extends|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|undefined|var|void|while|with|yield)\b/,
+			pattern: /(^|[^.]|\.\.\.\s*)\b(?:as|async(?=\s*(?:function\b|\(|[$\w\xA0-\uFFFF]|$))|await|break|case|class|const|continue|debugger|default|delete|do|else|enum|export|extends|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|undefined|var|void|while|with|yield)\b/,
 			lookbehind: true
 		},
 	],

prism.js

@@ -852,7 +852,7 @@ Prism.languages.javascript = Prism.languages.extend('clike', {
 			lookbehind: true
 		},
 		{
-			pattern: /(^|[^.])\b(?:as|async(?=\s*(?:function\b|\(|[$\w\xA0-\uFFFF]|$))|await|break|case|class|const|continue|debugger|default|delete|do|else|enum|export|extends|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|undefined|var|void|while|with|yield)\b/,
+			pattern: /(^|[^.]|\.\.\.\s*)\b(?:as|async(?=\s*(?:function\b|\(|[$\w\xA0-\uFFFF]|$))|await|break|case|class|const|continue|debugger|default|delete|do|else|enum|export|extends|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|undefined|var|void|while|with|yield)\b/,
 			lookbehind: true
 		},
 	],

tests/languages/javascript/spread_and_keyword_feature.test

@@ -0,0 +1,45 @@
+async function bar() {
+	return [...await foo()]
+}
+
+console.log([...new Set(numbers)])
+
+----------------------------------------------------
+
+[
+	["keyword", "async"],
+	["keyword", "function"],
+	["function", "bar"],
+	["punctuation", "("],
+	["punctuation", ")"],
+	["punctuation", "{"],
+	["keyword", "return"],
+	["punctuation", "["],
+	["operator", "..."],
+	["keyword", "await"],
+	["function", "foo"],
+	["punctuation", "("],
+	["punctuation", ")"],
+	["punctuation", "]"],
+	["punctuation", "}"],
+
+	"\r\n\r\nconsole",
+	["punctuation", "."],
+	["function", "log"],
+	["punctuation", "("],
+	["punctuation", "["],
+	["operator", "..."],
+	["keyword", "new"],
+	["class-name", [
+		"Set"
+	]],
+	["punctuation", "("],
+	"numbers",
+	["punctuation", ")"],
+	["punctuation", "]"],
+	["punctuation", ")"]
+]
+
+----------------------------------------------------
+
+Checks for the spread operator followed by a keyword.