diff --git a/optuna_dashboard/ts/components/GraphContour.tsx b/optuna_dashboard/ts/components/GraphContour.tsx
index b6c2ba20..b8301e20 100644
--- a/optuna_dashboard/ts/components/GraphContour.tsx
+++ b/optuna_dashboard/ts/components/GraphContour.tsx
@@ -86,7 +86,9 @@ export const Contour: FC<{
             <Select value={objectiveId} onChange={handleObjectiveChange}>
               {study.directions.map((d, i) => (
                 <MenuItem value={i} key={i}>
-                  {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                  {objectiveNames.length === study?.directions.length
+                    ? objectiveNames[i]
+                    : `${i}`}
                 </MenuItem>
               ))}
             </Select>
diff --git a/optuna_dashboard/ts/components/GraphEdf.tsx b/optuna_dashboard/ts/components/GraphEdf.tsx
index 94e052ec..6c706cc1 100644
--- a/optuna_dashboard/ts/components/GraphEdf.tsx
+++ b/optuna_dashboard/ts/components/GraphEdf.tsx
@@ -49,7 +49,9 @@ export const Edf: FC<{
             <Select value={objectiveId} onChange={handleObjectiveChange}>
               {study.directions.map((d, i) => (
                 <MenuItem value={i} key={i}>
-                  {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                  {objectiveNames.length === study?.directions.length
+                    ? objectiveNames[i]
+                    : `${i}`}
                 </MenuItem>
               ))}
             </Select>
diff --git a/optuna_dashboard/ts/components/GraphHistory.tsx b/optuna_dashboard/ts/components/GraphHistory.tsx
index 9826dfef..a60b35e2 100644
--- a/optuna_dashboard/ts/components/GraphHistory.tsx
+++ b/optuna_dashboard/ts/components/GraphHistory.tsx
@@ -93,7 +93,9 @@ export const GraphHistory: FC<{
             <Select value={objectiveId} onChange={handleObjectiveChange}>
               {study.directions.map((d, i) => (
                 <MenuItem value={i} key={i}>
-                  {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                  {objectiveNames.length === study?.directions.length
+                    ? objectiveNames[i]
+                    : `${i}`}
                 </MenuItem>
               ))}
             </Select>
diff --git a/optuna_dashboard/ts/components/GraphParallelCoordinate.tsx b/optuna_dashboard/ts/components/GraphParallelCoordinate.tsx
index 0c74c130..ca394e62 100644
--- a/optuna_dashboard/ts/components/GraphParallelCoordinate.tsx
+++ b/optuna_dashboard/ts/components/GraphParallelCoordinate.tsx
@@ -50,7 +50,9 @@ export const GraphParallelCoordinate: FC<{
             <Select value={objectiveId} onChange={handleObjectiveChange}>
               {study.directions.map((d, i) => (
                 <MenuItem value={i} key={i}>
-                  {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                  {objectiveNames.length === study?.directions.length
+                    ? objectiveNames[i]
+                    : `${i}`}
                 </MenuItem>
               ))}
             </Select>
diff --git a/optuna_dashboard/ts/components/GraphParetoFront.tsx b/optuna_dashboard/ts/components/GraphParetoFront.tsx
index 65933aaf..ef3dd646 100644
--- a/optuna_dashboard/ts/components/GraphParetoFront.tsx
+++ b/optuna_dashboard/ts/components/GraphParetoFront.tsx
@@ -56,7 +56,9 @@ export const GraphParetoFront: FC<{
               <Select value={objectiveXId} onChange={handleObjectiveXChange}>
                 {study.directions.map((d, i) => (
                   <MenuItem value={i} key={i}>
-                    {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                    {objectiveNames.length === study?.directions.length
+                      ? objectiveNames[i]
+                      : `${i}`}
                   </MenuItem>
                 ))}
               </Select>
@@ -66,7 +68,9 @@ export const GraphParetoFront: FC<{
               <Select value={objectiveYId} onChange={handleObjectiveYChange}>
                 {study.directions.map((d, i) => (
                   <MenuItem value={i} key={i}>
-                    {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                    {objectiveNames.length === study?.directions.length
+                      ? objectiveNames[i]
+                      : `${i}`}
                   </MenuItem>
                 ))}
               </Select>
diff --git a/optuna_dashboard/ts/components/GraphSlice.tsx b/optuna_dashboard/ts/components/GraphSlice.tsx
index 2ce96dcb..31231881 100644
--- a/optuna_dashboard/ts/components/GraphSlice.tsx
+++ b/optuna_dashboard/ts/components/GraphSlice.tsx
@@ -83,7 +83,9 @@ export const GraphSlice: FC<{
             <Select value={objectiveId} onChange={handleObjectiveChange}>
               {study.directions.map((d, i) => (
                 <MenuItem value={i} key={i}>
-                  {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                  {objectiveNames.length === study?.directions.length
+                    ? objectiveNames[i]
+                    : `${i}`}
                 </MenuItem>
               ))}
             </Select>
@@ -94,7 +96,9 @@ export const GraphSlice: FC<{
           <Select value={selected || ""} onChange={handleSelectedParam}>
             {paramNames?.map((p, i) => (
               <MenuItem value={p} key={i}>
-                {objectiveNames.length === study?.directions.length ? objectiveNames[i] : `${i}`}
+                {objectiveNames.length === study?.directions.length
+                  ? objectiveNames[i]
+                  : `${i}`}
               </MenuItem>
             ))}
           </Select>
diff --git a/optuna_dashboard/ts/components/TrialTable.tsx b/optuna_dashboard/ts/components/TrialTable.tsx
index 7d43c088..b936ee71 100644
--- a/optuna_dashboard/ts/components/TrialTable.tsx
+++ b/optuna_dashboard/ts/components/TrialTable.tsx
@@ -56,7 +56,10 @@ export const TrialTable: FC<{
     const objectiveColumns: DataGridColumn<Trial>[] =
       studyDetail.directions.map((s, objectiveId) => ({
         field: "values",
-        label: objectiveNames.length === studyDetail?.directions.length ? objectiveNames[objectiveId] : `Objective ${objectiveId}`,
+        label:
+          objectiveNames.length === studyDetail?.directions.length
+            ? objectiveNames[objectiveId]
+            : `Objective ${objectiveId}`,
         sortable: true,
         less: (firstEl, secondEl): number => {
           const firstVal = firstEl.values?.[objectiveId]