Add string operator enlist-input[] (#4948)

* Add string operator titlelist[]

* Update strings.js

* Update strings.js

* Add tests

core/modules/filters/strings.js

@@ -56,14 +56,14 @@ exports.trim = function(source,operator,options) {
 	return result;
 };
 
-// makeStringBinaryOperator(
-// 	function(a) {return [$tw.utils.trim(a)];}
-// );
-
 exports.split = makeStringBinaryOperator(
 	function(a,b) {return ("" + a).split(b);}
 );
 
+exports["enlist-input"] = makeStringBinaryOperator(
+	function(a) {return $tw.utils.parseStringArray("" + a);}
+);
+
 exports.join = makeStringReducingOperator(
 	function(accumulator,value,operand) {
 		if(accumulator === null) {

editions/test/tiddlers/tests/test-filters.js

@@ -160,6 +160,13 @@ function runTests(wiki) {
 		expect(wiki.filterTiddlers("[enlist[one two three]addsuffix[!]]").join(",")).toBe("one!,two!,three!");
 	});
 	
+	it("should handle the enlist-input operator", function() {
+		expect(wiki.filterTiddlers("[[one two three]enlist-input[]]").join(",")).toBe("one,two,three");
+		expect(wiki.filterTiddlers("[[one two three]] [[four five six]] +[enlist-input[]]").join(",")).toBe("one,two,three,four,five,six");
+		expect(wiki.filterTiddlers("[[one two three]] [[four five six]] [[seven eight]] +[enlist-input[]]").join(",")).toBe("one,two,three,four,five,six,seven,eight");
+		expect(wiki.filterTiddlers("[[]] +[enlist-input[]]").join(",")).toBe("");
+	});
+	
 	it("should handle the then and else operators", function() {
 		expect(wiki.filterTiddlers("[modifier[JoeBloggs]then[Susi]]").join(",")).toBe("Susi");
 		expect(wiki.filterTiddlers("[!modifier[JoeBloggs]then[Susi]]").join(",")).toBe("Susi,Susi,Susi,Susi,Susi,Susi,Susi,Susi");