diff --git a/.eslintrc.js b/.eslintrc.js
index 1f5e344..d5074d2 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -93,6 +93,7 @@ module.exports = {
     quotes: ['warn', 'single', { avoidEscape: true }],
     '@typescript-eslint/explicit-function-return-type': 'off',
     '@typescript-eslint/explicit-module-boundary-types': 'off',
+    '@typescript-eslint/strict-boolean-expressions': 'error',
 
     // allow debugger during development only
     'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off',
diff --git a/README.md b/README.md
index 781b974..1d9d962 100644
--- a/README.md
+++ b/README.md
@@ -17,8 +17,8 @@ https://github.com/Yentis/osu-local-scores/releases
 ## Building
 ```bash
 yarn install
-yarn dev::electron
-yarn build::electron
+yarn dev:electron
+yarn build:electron
 ```
 
 After building you will need to do the following steps (suggestions welcome):
diff --git a/package.json b/package.json
index 978f827..986a952 100644
--- a/package.json
+++ b/package.json
@@ -8,9 +8,9 @@
   "scripts": {
     "lint": "eslint --ext .js,.ts,.vue ./",
     "test": "echo \"No test specified\" && exit 0",
-    "dev::electron": "quasar dev -m electron",
-    "build::wasm": "cd src-wasm && cargo clippy && wasm-pack build",
-    "build::electron": "quasar build -m electron"
+    "dev:electron": "quasar dev -m electron",
+    "build:wasm": "cd src-wasm && cargo clippy && wasm-pack build",
+    "build:electron": "quasar build -m electron"
   },
   "devDependencies": {
     "@babel/eslint-parser": "^7.13.14",
diff --git a/src/components/ColumnBody.vue b/src/components/ColumnBody.vue
index b2e90d6..afffaad 100644
--- a/src/components/ColumnBody.vue
+++ b/src/components/ColumnBody.vue
@@ -6,7 +6,7 @@
         flat
         dense
         size="sm"
-        :icon="expand ? 'remove' : 'add'"
+        :icon="isExpanded ? 'remove' : 'add'"
         @click="expandRow"
       />
     </q-td>
@@ -90,7 +90,7 @@
 
   <q-tr
     v-for="(score, index) in row.scores"
-    v-show="expand && score !== firstScore"
+    v-show="isExpanded && score !== firstScore"
     :key="`${score.date}${index}`"
   >
     <q-td
@@ -176,8 +176,8 @@ export default defineComponent({
       type: Object as PropType<Score | undefined>,
       required: true
     },
-    expand: {
-      type: Boolean,
+    expanded: {
+      type: Object as PropType<Map<number, boolean>>,
       required: true
     }
   },
@@ -189,17 +189,31 @@ export default defineComponent({
     const platformService = PlatformService()
 
     const getImageSrc = (beatmap: Beatmap) => {
-      return beatmap.filePath
+      return (beatmap.filePath !== undefined && beatmap.filePath.length > 0)
         ? `atom://${osuPath.value}/Songs/${beatmap.filePath}`
         : `https://b.ppy.sh/thumb/${beatmap.beatmapsetId}l.jpg`
     }
 
+    const getExpanded = (key: number) => {
+      return props.expanded.get(key) === true
+    }
+
+    const key = ref(props.row.beatmap.beatmapId)
     const imageSrc = ref(getImageSrc(props.row.beatmap))
-    watch(props, () => { imageSrc.value = getImageSrc(props.row.beatmap) })
+    const isExpanded = ref(getExpanded(key.value))
+
+    watch(props, () => {
+      if (props.row.beatmap.beatmapId !== key.value) {
+        imageSrc.value = getImageSrc(props.row.beatmap)
+      }
+      key.value = props.row.beatmap.beatmapId
+
+      isExpanded.value = getExpanded(key.value)
+    })
 
     const onImageError = (beatmap: Beatmap) => { imageSrc.value = `https://b.ppy.sh/thumb/${beatmap.beatmapsetId}l.jpg` }
     const openURL = (url: string) => { platformService.openURL(url) }
-    const expandRow = () => { context.emit('update:expand') }
+    const expandRow = () => { context.emit('update:expand', props.row.beatmap.beatmapId) }
 
     return {
       visibleColumns,
@@ -208,6 +222,7 @@ export default defineComponent({
       onImageError,
       openURL,
       expandRow,
+      isExpanded,
       STATUS,
       UNSUBMITTED
     }
diff --git a/src/components/SettingsDialog.vue b/src/components/SettingsDialog.vue
index 1fc7cc0..665a9bc 100644
--- a/src/components/SettingsDialog.vue
+++ b/src/components/SettingsDialog.vue
@@ -99,7 +99,7 @@ export default defineComponent({
       platformService.openFilePicker(osuPath.value)
         .then((result) => {
           const newOsuPath = result.filePaths[0]
-          if (!newOsuPath) return
+          if (newOsuPath === undefined || newOsuPath.length === 0) return
 
           osuPath.value = newOsuPath
         })
diff --git a/src/components/cells/Combo.vue b/src/components/cells/Combo.vue
index 96b71de..3896618 100644
--- a/src/components/cells/Combo.vue
+++ b/src/components/cells/Combo.vue
@@ -7,15 +7,15 @@
       v-if="score"
       class="column"
     >
-      <span>{{ +score.combo.toFixed(2) }}</span>
+      <span>{{ formatCombo(score.combo) }}</span>
 
       <span
-        v-if="score.maxCombo !== undefined"
+        v-if="hasMaxCombo(score)"
         class="top-line"
-      >{{ +score.maxCombo.toFixed(2) }}</span>
+      >{{ formatCombo(score.maxCombo) }}</span>
 
       <span
-        v-if="MODES[score.gamemode] === MANIA || score.maxCombo !== undefined"
+        v-if="MODES[score.gamemode] === MANIA || hasMaxCombo(score)"
         class="top-line"
       >{{ formatAltCombo(score) }}</span>
     </div>
@@ -41,6 +41,11 @@ export default defineComponent({
   setup () {
     const { visibleColumns } = SettingsService()
 
+    const formatCombo = (combo?: number) => {
+      if (combo === undefined) return ''
+      return +combo.toFixed(2)
+    }
+
     const formatAltCombo = (score: Score) => {
       if (MODES[score.gamemode] === MANIA) {
         const altCombo = score.count300 !== 0 ? +(score.countGeki / score.count300).toFixed(2) : '∞'
@@ -55,7 +60,9 @@ export default defineComponent({
       visibleColumns,
       MODES,
       MANIA,
-      formatAltCombo
+      formatCombo,
+      formatAltCombo,
+      hasMaxCombo: (score: Score) => score.maxCombo !== undefined
     }
   }
 })
diff --git a/src/components/cells/Misses.vue b/src/components/cells/Misses.vue
index 52739ad..d58a5cb 100644
--- a/src/components/cells/Misses.vue
+++ b/src/components/cells/Misses.vue
@@ -3,7 +3,7 @@
     v-if="visibleColumns.includes('misses')"
     class="text-center"
   >
-    {{ score?.misses !== undefined ? score.misses : '?' }}
+    {{ formatMisses(score?.misses) }}
   </q-td>
 </template>
 
@@ -24,7 +24,16 @@ export default defineComponent({
 
   setup () {
     const { visibleColumns } = SettingsService()
-    return { visibleColumns }
+
+    const formatMisses = (misses?: number) => {
+      if (misses === undefined) return '?'
+      return misses
+    }
+
+    return {
+      visibleColumns,
+      formatMisses
+    }
   }
 })
 </script>
diff --git a/src/components/cells/Pp.vue b/src/components/cells/Pp.vue
index 8985ba6..0f6472d 100644
--- a/src/components/cells/Pp.vue
+++ b/src/components/cells/Pp.vue
@@ -4,20 +4,20 @@
     class="text-center"
   >
     <div
-      v-if="score?.pp !== undefined"
+      v-if="isDefined(score?.pp)"
       class="column"
     >
-      <span>{{ +score.pp.toFixed(2) }}</span>
+      <span>{{ formatPp(score?.pp) }}</span>
 
       <span
-        v-if="score.maxPp !== undefined"
+        v-if="isDefined(score?.maxPp)"
         class="top-line"
-      >{{ +score.maxPp.toFixed(2) }}</span>
+      >{{ formatPp(score?.maxPp) }}</span>
 
       <span
-        v-if="score.maxPp !== undefined"
+        v-if="isDefined(score?.maxPp)"
         class="top-line"
-      >{{ score.maxPp !== 0 ? `${+((score.pp / score.maxPp) * 100).toFixed(2)}%` : '∞' }}</span>
+      >{{ formatAltPp(score) }}</span>
     </div>
     <span v-else>?</span>
   </q-td>
@@ -40,7 +40,23 @@ export default defineComponent({
 
   setup () {
     const { visibleColumns } = SettingsService()
-    return { visibleColumns }
+
+    const formatPp = (pp?: number) => {
+      if (pp === undefined) return ''
+      return +pp.toFixed(2)
+    }
+
+    const formatAltPp = (score?: Score) => {
+      if (score?.pp === undefined || score?.maxPp === undefined) return ''
+      return score.maxPp !== 0 ? `${+((score.pp / score.maxPp) * 100).toFixed(2)}%` : '∞'
+    }
+
+    return {
+      visibleColumns,
+      isDefined: (input?: unknown) => input !== undefined,
+      formatPp,
+      formatAltPp
+    }
   }
 })
 </script>
diff --git a/src/pages/Index.vue b/src/pages/Index.vue
index b6f7617..67ba21c 100644
--- a/src/pages/Index.vue
+++ b/src/pages/Index.vue
@@ -22,8 +22,8 @@
       <ColumnBody
         :row="props.row"
         :first-score="props.row.scores[0]"
-        :expand="props.expand"
-        @update:expand="props.expand = !props.expand"
+        :expanded="expanded"
+        @update:expand="expand"
       />
     </template>
   </q-table>
@@ -113,35 +113,35 @@ export default defineComponent({
           break
         }
         case COLUMNS.gamemode: {
-          doScoreSort(rows, (score) => score?.gamemode || 0, descending)
+          doScoreSort(rows, (score) => score?.gamemode !== undefined ? score.gamemode : 0, descending)
           break
         }
         case COLUMNS.score: {
-          doScoreSort(rows, (score) => score?.score || 0, descending)
+          doScoreSort(rows, (score) => score?.score !== undefined ? score.score : 0, descending)
           break
         }
         case COLUMNS.grade: {
-          doScoreSort(rows, (score) => score?.grade || 0, descending)
+          doScoreSort(rows, (score) => score?.grade !== undefined ? score.grade : 0, descending)
           break
         }
         case COLUMNS.accuracy: {
-          doScoreSort(rows, (score) => score?.accuracy || 0, descending)
+          doScoreSort(rows, (score) => score?.accuracy !== undefined ? score.accuracy : 0, descending)
           break
         }
         case COLUMNS.misses: {
-          doScoreSort(rows, (score) => score?.misses || 0, descending)
+          doScoreSort(rows, (score) => score?.misses !== undefined ? score.misses : 0, descending)
           break
         }
         case COLUMNS.combo: {
-          doScoreSort(rows, (score) => score?.combo || 0, descending)
+          doScoreSort(rows, (score) => score?.combo !== undefined ? score.combo : 0, descending)
           break
         }
         case COLUMNS.date: {
-          doScoreSort(rows, (score) => score?.date ? new Date(score.date).getTime() : 0, descending)
+          doScoreSort(rows, (score) => score?.date !== undefined ? new Date(score.date).getTime() : 0, descending)
           break
         }
         case COLUMNS.pp: {
-          doScoreSort(rows, (score) => score?.pp || 0, descending)
+          doScoreSort(rows, (score) => score?.pp !== undefined ? score.pp : 0, descending)
           break
         }
       }
@@ -149,6 +149,15 @@ export default defineComponent({
       return descending ? rows.reverse() : rows
     }
 
+    const expanded = ref(new Map<number, boolean>())
+    const expand = (key: number) => {
+      const map = expanded.value
+      const isExpanded = map.get(key) === true
+
+      map.set(key, !isExpanded)
+      expanded.value = map
+    }
+
     return {
       table,
       columns,
@@ -156,7 +165,9 @@ export default defineComponent({
       filter,
       openURL,
       visibleColumns,
-      doSort
+      doSort,
+      expanded,
+      expand
     }
   }
 })
diff --git a/src/router/index.ts b/src/router/index.ts
index 11dd9e2..dd3c769 100644
--- a/src/router/index.ts
+++ b/src/router/index.ts
@@ -17,7 +17,8 @@ import routes from './routes'
  */
 
 export default route(function (/* { store, ssrContext } */) {
-  const createHistory = process.env.SERVER
+  const server = (process.env.SERVER as unknown) as boolean
+  const createHistory = server
     ? createMemoryHistory
     : (process.env.VUE_ROUTER_MODE === 'history' ? createWebHistory : createWebHashHistory)
 
diff --git a/src/services/UpdateService.ts b/src/services/UpdateService.ts
index f8d7e83..2a1a843 100644
--- a/src/services/UpdateService.ts
+++ b/src/services/UpdateService.ts
@@ -28,7 +28,7 @@ export class UpdateService {
     if (update) { this.showUpdateAvailable(update) }
 
     const changelog = await this.getChangelog()
-    if (!changelog) return
+    if (changelog === undefined) return
 
     Dialog.create({
       component: ConfirmationDialog,
@@ -48,8 +48,9 @@ export class UpdateService {
     return githubReleases
   }
 
-  private getVersion () {
-    return LocalStorage.getItem(VERSION) || ''
+  private getVersion (): string {
+    const version = LocalStorage.getItem(VERSION)
+    return typeof version === 'string' ? version : ''
   }
 
   private async getChangelog (): Promise<string | undefined> {
diff --git a/src/worker/Worker.ts b/src/worker/Worker.ts
index d20015f..354ca23 100644
--- a/src/worker/Worker.ts
+++ b/src/worker/Worker.ts
@@ -158,7 +158,7 @@ function filterBeatmaps (filter: Filter): DatabaseResponse[] {
       }
 
       // Max Combo
-      const maxCombo = score.maxCombo || 0
+      const maxCombo = score.maxCombo !== undefined ? score.maxCombo : 0
       const maxComboMin = typeof filter.maxComboMin === 'number' ? filter.maxComboMin : maxCombo
       const maxComboMax = typeof filter.maxComboMax === 'number' ? filter.maxComboMax : maxCombo
       if (maxCombo < maxComboMin || maxCombo > maxComboMax) {
@@ -216,14 +216,14 @@ function filterBeatmaps (filter: Filter): DatabaseResponse[] {
 
       // Date
       const date = new Date(score.date).getTime()
-      const dateMin = filter.dateMin ? new Date(filter.dateMin).getTime() : date
-      const dateMax = filter.dateMax ? new Date(filter.dateMax).getTime() : date
+      const dateMin = filter.dateMin !== undefined ? new Date(filter.dateMin).getTime() : date
+      const dateMax = filter.dateMax !== undefined ? new Date(filter.dateMax).getTime() : date
       if (date < dateMin || date > dateMax) {
         return false
       }
 
       // PP
-      const pp = score.pp || 0
+      const pp = score.pp !== undefined ? score.pp : 0
       const ppMin = typeof filter.ppMin === 'number' ? filter.ppMin : pp
       const ppMax = typeof filter.ppMax === 'number' ? filter.ppMax : pp
       if (pp < ppMin || pp > ppMax) {
@@ -231,7 +231,7 @@ function filterBeatmaps (filter: Filter): DatabaseResponse[] {
       }
 
       // Max PP
-      const maxPp = score.maxPp || 0
+      const maxPp = score.maxPp !== undefined ? score.maxPp : 0
       const maxPpMin = typeof filter.maxPpMin === 'number' ? filter.maxPpMin : maxPp
       const maxPpMax = typeof filter.maxPpMax === 'number' ? filter.maxPpMax : maxPp
       if (maxPp < maxPpMin || maxPp > maxPpMax) {
@@ -305,7 +305,7 @@ async function calculatePpValues (osuPath: string, beatmaps: DatabaseResponse[])
     }
 
     const filePath = beatmap.beatmap.filePath
-    if (!filePath) {
+    if (filePath === undefined || filePath.length === 0) {
       continue
     }