remove nested terneries and enable lint

@hgiesel would you mind quickly checking I've correctly captured
the logic here?

ts/.eslintrc.js

@@ -8,6 +8,7 @@ module.exports = {
     plugins: ["@typescript-eslint"],
     rules: {
         "prefer-const": "warn",
+        "no-nested-ternary": "warn",
         "@typescript-eslint/ban-ts-comment": "warn",
         "@typescript-eslint/no-unused-vars": [
             "warn",

ts/editor-toolbar/helpers.ts

@@ -4,11 +4,9 @@ export function mergeTooltipAndShortcut(
     tooltip: string | undefined,
     shortcutLabel: string | undefined
 ): string | undefined {
-    return tooltip
-        ? shortcutLabel
-            ? `${tooltip} (${shortcutLabel})`
-            : tooltip
-        : shortcutLabel
-        ? `(${shortcutLabel})`
-        : undefined;
+    let buf = tooltip ?? "";
+    if (shortcutLabel) {
+        buf = `${buf} (${shortcutLabel})`;
+    }
+    return buf;
 }

ts/editor-toolbar/identifiable.ts

@@ -8,14 +8,11 @@ function normalize<T extends Identifiable>(
     values: T[],
     idOrIndex: string | number
 ): number {
-    const normalizedIndex =
-        typeof idOrIndex === "string"
-            ? values.findIndex((value) => value.id === idOrIndex)
-            : idOrIndex >= 0
-            ? idOrIndex
-            : values.length + idOrIndex;
-
-    return normalizedIndex >= values.length ? -1 : normalizedIndex;
+    if (typeof idOrIndex === "string") {
+        return values.findIndex((value) => value.id === idOrIndex);
+    } else {
+        return idOrIndex >= values.length ? -1 : idOrIndex;
+    }
 }
 
 export function search<T extends Identifiable>(

ts/graphs/calendar.ts

@@ -69,15 +69,7 @@ export function gatherData(
         reviewCount.set(day, count + 1);
     }
 
-    const timeFunction =
-        firstDayOfWeek === Weekday.MONDAY
-            ? timeMonday
-            : firstDayOfWeek === Weekday.FRIDAY
-            ? timeFriday
-            : firstDayOfWeek === Weekday.SATURDAY
-            ? timeSaturday
-            : timeSunday;
-
+    const timeFunction = timeFunctionForDay(firstDayOfWeek);
     const weekdayLabels: number[] = [];
     for (let i = 0; i < 7; i++) {
         weekdayLabels.push((firstDayOfWeek + i) % 7);
@@ -224,3 +216,16 @@ export function renderCalendar(
         .duration(800)
         .attr("fill", (d: DayDatum) => (d.count === 0 ? emptyColour : blues(d.count)!));
 }
+
+function timeFunctionForDay(firstDayOfWeek: WeekdayType): CountableTimeInterval {
+    switch (firstDayOfWeek) {
+        case Weekday.MONDAY:
+            return timeMonday;
+        case Weekday.FRIDAY:
+            return timeFriday;
+        case Weekday.SATURDAY:
+            return timeSaturday;
+        default:
+            return timeSunday;
+    }
+}

ts/html-filter/index.ts

@@ -41,12 +41,7 @@ export function filterHTML(html: string, internal: boolean, extended: boolean):
     const template = document.createElement("template");
     template.innerHTML = html;
 
-    const mode = internal
-        ? FilterMode.Internal
-        : extended
-        ? FilterMode.Extended
-        : FilterMode.Basic;
-
+    const mode = getFilterMode(internal, extended);
     const content = template.content;
     const filter = filterNode(filters[mode]);
 
@@ -54,3 +49,13 @@ export function filterHTML(html: string, internal: boolean, extended: boolean):
 
     return outputHTMLProcessors[mode](template.innerHTML);
 }
+
+function getFilterMode(internal: boolean, extended: boolean): FilterMode {
+    if (internal) {
+        return FilterMode.Internal;
+    } else if (extended) {
+        return FilterMode.Extended;
+    } else {
+        return FilterMode.Basic;
+    }
+}

ts/lib/shortcuts.ts

@@ -53,13 +53,15 @@ const keyToCharacterMap = {
 };
 
 function keyToPlatformString(key: string): string {
-    return key.startsWith(alphabeticPrefix)
-        ? key.slice(alphabeticPrefix.length)
-        : key.startsWith(numericPrefix)
-        ? key.slice(numericPrefix.length)
-        : Object.prototype.hasOwnProperty.call(keyToCharacterMap, key)
-        ? keyToCharacterMap[key]
-        : key;
+    if (key.startsWith(alphabeticPrefix)) {
+        return key.slice(alphabeticPrefix.length);
+    } else if (key.startsWith(numericPrefix)) {
+        return key.slice(numericPrefix.length);
+    } else if (Object.prototype.hasOwnProperty.call(keyToCharacterMap, key)) {
+        return keyToCharacterMap[key];
+    } else {
+        return key;
+    }
 }
 
 function toPlatformString(modifiersAndKey: string[]): string {