From d5cf4112fa682efa5b621cf164bd139fc354da36 Mon Sep 17 00:00:00 2001 From: Robin Munn Date: Fri, 25 Sep 2020 00:37:51 +0700 Subject: [PATCH] Joining an empty list should return an empty list (#4853) --- core/modules/filters/strings.js | 3 +++ editions/test/tiddlers/tests/test-filters.js | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/core/modules/filters/strings.js b/core/modules/filters/strings.js index 014284b20..625acd9a7 100644 --- a/core/modules/filters/strings.js +++ b/core/modules/filters/strings.js @@ -90,6 +90,9 @@ function makeStringReducingOperator(fnCalc,initialValue) { source(function(tiddler,title) { result.push(title); }); + if(result.length === 0) { + return []; + } return [result.reduce(function(accumulator,currentValue) { return fnCalc(accumulator,currentValue,operator.operand || ""); },initialValue) || ""]; diff --git a/editions/test/tiddlers/tests/test-filters.js b/editions/test/tiddlers/tests/test-filters.js index 4c2673d2c..84e17ef83 100644 --- a/editions/test/tiddlers/tests/test-filters.js +++ b/editions/test/tiddlers/tests/test-filters.js @@ -463,7 +463,7 @@ function runTests(wiki) { expect(wiki.filterTiddlers("John Paul George Ringo +[split[e]]").join(",")).toBe("John,Paul,G,org,,Ringo"); expect(wiki.filterTiddlers("John Paul George Ringo +[join[ ]split[e]join[ee]split[ ]]").join(",")).toBe("John,Paul,Geeorgee,Ringo"); // Ensure that join doesn't return null if passed empty list - expect(wiki.filterTiddlers("Test +[butlast[]join[ ]]")).toEqual([""]); + expect(wiki.filterTiddlers("Test +[butlast[]join[ ]]")).toEqual([]); // Ensure that join correctly handles empty strings in source expect(wiki.filterTiddlers("[[]] Paul +[join[-]]").join(",")).toBe("-Paul"); expect(wiki.filterTiddlers("[[ John ]] [[Paul ]] [[ George]] Ringo +[trim[]join[-]]").join(",")).toBe("John-Paul-George-Ringo");