diff --git a/src/compile/selection/inputs.ts b/src/compile/selection/inputs.ts
index 8e8e6c3afd..5259fcea00 100644
--- a/src/compile/selection/inputs.ts
+++ b/src/compile/selection/inputs.ts
@@ -55,7 +55,7 @@ const inputBindings: SelectionCompiler<'point'> = {
   signals: (model, selCmpt, signals) => {
     const name = selCmpt.name;
     const proj = selCmpt.project;
-    const signal: NewSignal = signals.filter(s => s.name === name + TUPLE)[0];
+    const signal: NewSignal = signals.find(s => s.name === name + TUPLE);
     const fields = name + TUPLE_FIELDS;
     const values = proj.items.map(p => varName(`${name}_${p.field}`));
     const valid = values.map(v => `${v} !== null`).join(' && ');
diff --git a/src/compile/selection/interval.ts b/src/compile/selection/interval.ts
index 12456bfa31..1c8a7aed05 100644
--- a/src/compile/selection/interval.ts
+++ b/src/compile/selection/interval.ts
@@ -47,7 +47,7 @@ const interval: SelectionCompiler<'interval'> = {
         }
 
         const filters = array((evt.between[0].filter ??= []));
-        if (filters.indexOf(filterExpr) < 0) {
+        if (!filters.includes(filterExpr)) {
           filters.push(filterExpr);
         }
       }
diff --git a/src/compile/selection/nearest.ts b/src/compile/selection/nearest.ts
index 1a66f0032c..9c835ac727 100644
--- a/src/compile/selection/nearest.ts
+++ b/src/compile/selection/nearest.ts
@@ -58,7 +58,7 @@ const nearest: SelectionCompiler<'point'> = {
       const name = mark.name ?? '';
       if (name === model.component.mark[0].name) {
         index = i;
-      } else if (name.indexOf(VORONOI) >= 0) {
+      } else if (name.includes(VORONOI)) {
         exists = true;
       }
     });
diff --git a/src/compile/selection/scales.ts b/src/compile/selection/scales.ts
index 0c2b577713..60f9b7f59a 100644
--- a/src/compile/selection/scales.ts
+++ b/src/compile/selection/scales.ts
@@ -57,9 +57,9 @@ const scaleBindings: SelectionCompiler<'interval'> = {
     // state is captured by the top-level signals that we insert and "push
     // outer" to from within the units. We need to reassemble this state into
     // the top-level named signal, except no single selCmpt has a global view.
-    const namedSg: NewSignal = signals.filter(s => s.name === selCmpt.name)[0];
+    const namedSg: NewSignal = signals.find(s => s.name === selCmpt.name);
     let update = namedSg.update;
-    if (update.indexOf(VL_SELECTION_RESOLVE) >= 0) {
+    if (update.includes(VL_SELECTION_RESOLVE)) {
       namedSg.update = `{${bound
         .map(proj => `${stringValue(replacePathInField(proj.field))}: ${proj.signals.data}`)
         .join(', ')}}`;
diff --git a/src/compile/selection/translate.ts b/src/compile/selection/translate.ts
index 25cce1a447..8431ae10b0 100644
--- a/src/compile/selection/translate.ts
+++ b/src/compile/selection/translate.ts
@@ -80,7 +80,7 @@ function onDelta(
   const delta = name + DELTA;
   const channel = proj.channel as ScaleChannel;
   const boundScales = scalesCompiler.defined(selCmpt);
-  const signal = signals.filter(s => s.name === proj.signals[boundScales ? 'data' : 'visual'])[0];
+  const signal = signals.find(s => s.name === proj.signals[boundScales ? 'data' : 'visual']);
   const sizeSg = model.getSizeSignalRef(size).signal;
   const scaleCmpt = model.getScaleComponent(channel);
   const scaleType = scaleCmpt && scaleCmpt.get('type');
diff --git a/src/compile/selection/zoom.ts b/src/compile/selection/zoom.ts
index a75a370fc5..a326dd6969 100644
--- a/src/compile/selection/zoom.ts
+++ b/src/compile/selection/zoom.ts
@@ -82,7 +82,7 @@ function onDelta(
   const name = selCmpt.name;
   const channel = proj.channel as ScaleChannel;
   const boundScales = scalesCompiler.defined(selCmpt);
-  const signal = signals.filter(s => s.name === proj.signals[boundScales ? 'data' : 'visual'])[0];
+  const signal = signals.find(s => s.name === proj.signals[boundScales ? 'data' : 'visual']);
   const sizeSg = model.getSizeSignalRef(size).signal;
   const scaleCmpt = model.getScaleComponent(channel);
   const scaleType = scaleCmpt && scaleCmpt.get('type');