changing slice to trim

            savedRulesMenu: _l("Recently used rules"),

            // Get the 61 character values for ASCII 65 (A) to 126 (~), which is how handson table labels its columns

            // This ensures the handson table headers are available for passing to the display method in formatPreview

            hotHeaders: [... new Array(61).keys()].map(i => String.fromCharCode(i + 65))

            hotHeaders: [...new Array(61).keys()].map((i) => String.fromCharCode(i + 65)),

        };

    },

    computed: {

                    return prettyString;

                } else {

                    prettyString += delim + RULES[element.type].display(element, this.hotHeaders);

                    prettyString = prettyString.slice(0, -1);

                    prettyString = prettyString.trim();

                    delim = ", ";

                    numOfPreviewedRules++;

                }