Add option to Zotero.Utilities.ellipsize() to truncate at word boundary

chrome/content/zotero/xpcom/debug.js

@@ -158,7 +158,7 @@ Zotero.Debug = new function () {
 		if (maxLineLength) {
 			for (var i=0, len=output.length; i<len; i++) {
 				if (output[i].length > maxLineLength) {
-					output[i] = Zotero.Utilities.ellipsize(output[i], maxLineLength, true);
+					output[i] = Zotero.Utilities.ellipsize(output[i], maxLineLength, false, true);
 				}
 			}
 		}

chrome/content/zotero/xpcom/utilities.js

@@ -842,18 +842,32 @@ Zotero.Utilities = {
 	/**
 	 * Shorten and add an ellipsis to a string if necessary
 	 *
-	 * @param	{String}	str
-	 * @param	{Integer}	len
-	 * @param	{Boolean}	[countChars=false]
+	 * @param {String}	str
+	 * @param {Integer}	len
+	 * @param {Boolean} [wordBoundary=false]
+	 * @param {Boolean} [countChars=false]
 	 */
-	"ellipsize":function (str, len, countChars) {
+	ellipsize: function (str, len, wordBoundary = false, countChars) {
 		if (!len) {
 			throw ("Length not specified in Zotero.Utilities.ellipsize()");
 		}
-		if (str.length > len) {
-			return str.substr(0, len) + '\u2026' + (countChars ? ' (' + str.length + ' chars)' : '');
+		if (str.length <= len) {
+			return str;
 		}
-		return str;
+		let radius = Math.min(len, 5);
+		if (wordBoundary) {
+			let min = len - radius;
+			// If next character is a space, include that so we stop at len
+			if (str.charAt(len).match(/\s/)) {
+				radius++;
+			}
+			// Remove trailing characters and spaces, up to radius
+			str = str.substr(0, min) + str.substr(min, radius).replace(/\W*\s\S*$/, "");
+		}
+		else {
+			str = str.substr(0, len)
+		}
+		return str + '\u2026' + (countChars ? ' (' + str.length + ' chars)' : '');
 	},
 	
 	/**

test/tests/utilitiesTest.js

@@ -370,4 +370,36 @@ describe("Zotero.Utilities", function() {
 			assert.equal(item.getField('title'), jsonAttachment.title, 'title imported correctly');
 		});
 	});
+	
+	describe("#ellipsize()", function () {
+		describe("with wordBoundary", function () {
+			it("should truncate at word boundary", function* () {
+				assert.equal(Zotero.Utilities.ellipsize("abc def ghi", 3, true), "abc…");
+			});
+			
+			it("should trim whitespace after word boundary", function* () {
+				assert.equal(Zotero.Utilities.ellipsize("abc def ghi", 4, true), "abc…");
+			});
+			
+			it("should trim characters after word boundary", function () {
+				assert.equal(Zotero.Utilities.ellipsize("abc def ghi", 5, true), "abc…");
+			});
+			
+			it("should truncate in the middle of a word", function () {
+				assert.equal(Zotero.Utilities.ellipsize("abcdefghi", 6, true), "abcdef…");
+			});
+			
+			it("should truncate at word boundary with previous space within radius", function () {
+				assert.equal(Zotero.Utilities.ellipsize("abc def ghi", 7, true), "abc def…");
+			});
+			
+			it("should return string as is if shorter than length", function () {
+				assert.equal(Zotero.Utilities.ellipsize("abcdefg", 8, true), "abcdefg");
+			});
+			
+			it("should return string as is if equal to length", function () {
+				assert.equal(Zotero.Utilities.ellipsize("abcdefgh", 8, true), "abcdefgh");
+			});
+		});
+	});
 });