diff --git a/packages/core/src/editor/EditorToolbar.ts b/packages/core/src/editor/EditorToolbar.ts
index 96e9b91a3..bb6a27186 100644
--- a/packages/core/src/editor/EditorToolbar.ts
+++ b/packages/core/src/editor/EditorToolbar.ts
@@ -666,7 +666,7 @@ export class EditorToolbarCodec extends ObjectCodec {
                       }
                     }
                   } else {
-                    let select: HTMLSelectElement;
+                    const select: HTMLSelectElement = into.addCombo();
 
                     const create = () => {
                       const template = editor.templates[select.value];
@@ -688,7 +688,6 @@ export class EditorToolbarCodec extends ObjectCodec {
                     };
 
                     const img = into.addPrototype(as, icon, create, null, null, toggle);
-                    select = into.addCombo();
 
                     // Selects the toolbar icon if a selection change
                     // is made in the corresponding combobox.
diff --git a/packages/core/src/gui/MaxWindow.ts b/packages/core/src/gui/MaxWindow.ts
index 74805af55..2cb6af317 100644
--- a/packages/core/src/gui/MaxWindow.ts
+++ b/packages/core/src/gui/MaxWindow.ts
@@ -193,7 +193,6 @@ class MaxWindow extends EventSource {
     super();
 
     if (content != null) {
-      minimizable = minimizable;
       this.content = content;
       this.init(x, y, width, height, style);
 
diff --git a/packages/core/src/util/arrayUtils.ts b/packages/core/src/util/arrayUtils.ts
index e863a8be0..f3f9705fc 100644
--- a/packages/core/src/util/arrayUtils.ts
+++ b/packages/core/src/util/arrayUtils.ts
@@ -93,11 +93,11 @@ export const equalEntries = (a: Properties | null, b: Properties | null) => {
     return false;
   }
   if (a && b) {
-    for (var key in b) {
+    for (const key in b) {
       count++;
     }
 
-    for (var key in a) {
+    for (const key in a) {
       count--;
 
       if ((!Number.isNaN(a[key]) || !Number.isNaN(b[key])) && a[key] !== b[key]) {
diff --git a/packages/core/src/view/image/ImageExport.ts b/packages/core/src/view/image/ImageExport.ts
index 1cc5b4d1e..4f2d05721 100644
--- a/packages/core/src/view/image/ImageExport.ts
+++ b/packages/core/src/view/image/ImageExport.ts
@@ -48,8 +48,6 @@ import { Graph } from '../Graph';
  * @class ImageExport
  */
 class ImageExport {
-  constructor() {}
-
   /**
    * Specifies if overlays should be included in the export. Default is false.
    */
diff --git a/packages/core/src/view/layout/HierarchicalLayout.ts b/packages/core/src/view/layout/HierarchicalLayout.ts
index acce95b01..2e0aef25a 100644
--- a/packages/core/src/view/layout/HierarchicalLayout.ts
+++ b/packages/core/src/view/layout/HierarchicalLayout.ts
@@ -426,7 +426,7 @@ class HierarchicalLayout extends GraphLayout {
       let filledVertexSetEmpty = true;
 
       // Poor man's isSetEmpty
-      for (var key in filledVertexSet) {
+      for (const key in filledVertexSet) {
         if (filledVertexSet[key] != null) {
           filledVertexSetEmpty = false;
           break;
@@ -464,7 +464,7 @@ class HierarchicalLayout extends GraphLayout {
         filledVertexSetEmpty = true;
 
         // Poor man's isSetEmpty
-        for (var key in filledVertexSet) {
+        for (const key in filledVertexSet) {
           if (filledVertexSet[key] != null) {
             filledVertexSetEmpty = false;
             break;
@@ -503,7 +503,7 @@ class HierarchicalLayout extends GraphLayout {
       const vertexSet = hierarchyVertices[i];
       const tmp = [];
 
-      for (var key in vertexSet) {
+      for (const key in vertexSet) {
         tmp.push(vertexSet[key]);
       }
 
@@ -652,8 +652,7 @@ class HierarchicalLayout extends GraphLayout {
             let netCount = 1;
 
             for (let j = 0; j < edges.length; j++) {
-              if (j === i) {
-              } else {
+              if (j !== i) {
                 const isSource2 = edgeIsSource[j];
                 const otherTerm = this.getVisibleTerminal(edges[j], !isSource2);
 
diff --git a/packages/core/src/view/layout/SwimlaneLayout.ts b/packages/core/src/view/layout/SwimlaneLayout.ts
index 80f0bb2c3..2766e538b 100644
--- a/packages/core/src/view/layout/SwimlaneLayout.ts
+++ b/packages/core/src/view/layout/SwimlaneLayout.ts
@@ -547,7 +547,7 @@ class SwimlaneLayout extends GraphLayout {
       let filledVertexSetEmpty = true;
 
       // Poor man's isSetEmpty
-      for (var key in filledVertexSet) {
+      for (const key in filledVertexSet) {
         if (filledVertexSet[key] != null) {
           filledVertexSetEmpty = false;
           break;
@@ -596,7 +596,7 @@ class SwimlaneLayout extends GraphLayout {
         filledVertexSetEmpty = true;
 
         // Poor man's isSetEmpty
-        for (var key in filledVertexSet) {
+        for (const key in filledVertexSet) {
           if (filledVertexSet[key] != null) {
             filledVertexSetEmpty = false;
             break;
@@ -626,7 +626,7 @@ class SwimlaneLayout extends GraphLayout {
     }
 
     const tmp = [];
-    for (var key in allVertexSet) {
+    for (const key in allVertexSet) {
       tmp.push(allVertexSet[key]);
     }
 
diff --git a/packages/core/src/view/layout/hierarchical/CoordinateAssignment.ts b/packages/core/src/view/layout/hierarchical/CoordinateAssignment.ts
index 2dade39fd..734a7a1e9 100644
--- a/packages/core/src/view/layout/hierarchical/CoordinateAssignment.ts
+++ b/packages/core/src/view/layout/hierarchical/CoordinateAssignment.ts
@@ -1118,7 +1118,7 @@ class CoordinateAssignment extends HierarchicalLayoutStage {
               // Calculate width requirements for all connected edges
               for (let j = 0; j < sortedCells.length; j++) {
                 const innerCell = <GraphHierarchyNode>sortedCells[j].cell;
-                var connections;
+                let connections: GraphHierarchyEdge[] | undefined;
 
                 if (innerCell.isVertex()) {
                   // Get the connecting edge
diff --git a/packages/core/src/view/layout/hierarchical/GraphHierarchyModel.ts b/packages/core/src/view/layout/hierarchical/GraphHierarchyModel.ts
index eff12e5bd..ec8e9b589 100644
--- a/packages/core/src/view/layout/hierarchical/GraphHierarchyModel.ts
+++ b/packages/core/src/view/layout/hierarchical/GraphHierarchyModel.ts
@@ -283,11 +283,8 @@ class GraphHierarchyModel {
 
     while (startNodes.length > 0) {
       const internalNode = startNodes[0];
-      var layerDeterminingEdges;
-      var edgesToBeMarked: GraphHierarchyEdge[] | null;
-
-      layerDeterminingEdges = internalNode.connectsAsTarget;
-      edgesToBeMarked = internalNode.connectsAsSource;
+      const layerDeterminingEdges = internalNode.connectsAsTarget;
+      const edgesToBeMarked = internalNode.connectsAsSource;
 
       // flag to keep track of whether or not all layer determining
       // edges have been scanned
diff --git a/packages/core/src/view/layout/hierarchical/MedianHybridCrossingReduction.ts b/packages/core/src/view/layout/hierarchical/MedianHybridCrossingReduction.ts
index 018f383c9..86cec82c4 100644
--- a/packages/core/src/view/layout/hierarchical/MedianHybridCrossingReduction.ts
+++ b/packages/core/src/view/layout/hierarchical/MedianHybridCrossingReduction.ts
@@ -465,21 +465,11 @@ class MedianHybridCrossingReduction extends HierarchicalLayoutStage {
       // sweeps
       // TODO re-implement some kind of nudge
       // medianValues[i].nudge = !downwardSweep;
-      var nextLevelConnectedCells;
+      const nextLevelConnectedCells = downwardSweep
+        ? cell.getNextLayerConnectedCells(rankValue)
+        : cell.getPreviousLayerConnectedCells(rankValue);
 
-      if (downwardSweep) {
-        nextLevelConnectedCells = cell.getNextLayerConnectedCells(rankValue);
-      } else {
-        nextLevelConnectedCells = cell.getPreviousLayerConnectedCells(rankValue);
-      }
-
-      var nextRankValue;
-
-      if (downwardSweep) {
-        nextRankValue = rankValue + 1;
-      } else {
-        nextRankValue = rankValue - 1;
-      }
+      const nextRankValue = downwardSweep ? rankValue + 1 : rankValue - 1;
 
       if (nextLevelConnectedCells != null && nextLevelConnectedCells.length !== 0) {
         sorterEntry.medianValue = this.medianValue(
diff --git a/packages/core/src/view/layout/hierarchical/SwimlaneModel.ts b/packages/core/src/view/layout/hierarchical/SwimlaneModel.ts
index 7a5bf4cac..4a92c36fd 100644
--- a/packages/core/src/view/layout/hierarchical/SwimlaneModel.ts
+++ b/packages/core/src/view/layout/hierarchical/SwimlaneModel.ts
@@ -318,11 +318,8 @@ class SwimlaneModel {
 
     while (startNodes.length > 0) {
       const internalNode = startNodes[0];
-      var layerDeterminingEdges;
-      var edgesToBeMarked;
-
-      layerDeterminingEdges = internalNode.connectsAsTarget;
-      edgesToBeMarked = internalNode.connectsAsSource;
+      const layerDeterminingEdges = internalNode.connectsAsTarget;
+      const edgesToBeMarked = internalNode.connectsAsSource;
 
       // flag to keep track of whether or not all layer determining
       // edges have been scanned
diff --git a/packages/core/src/view/other/Outline.ts b/packages/core/src/view/other/Outline.ts
index 67f471cef..49e258213 100644
--- a/packages/core/src/view/other/Outline.ts
+++ b/packages/core/src/view/other/Outline.ts
@@ -172,7 +172,7 @@ class Outline {
         outline.fireMouseEvent(InternalEvent.MOUSE_MOVE, new InternalMouseEvent(evt));
       };
 
-      var redirect2 = (evt: MouseEvent) => {
+      const redirect2 = (evt: MouseEvent) => {
         const outline = <Graph>this.outline;
         InternalEvent.removeGestureListeners(<Listenable>t, null, redirect, redirect2);
         outline.fireMouseEvent(InternalEvent.MOUSE_UP, new InternalMouseEvent(evt));
diff --git a/packages/core/src/view/style/EdgeStyle.ts b/packages/core/src/view/style/EdgeStyle.ts
index 94655ac2c..12ca58479 100644
--- a/packages/core/src/view/style/EdgeStyle.ts
+++ b/packages/core/src/view/style/EdgeStyle.ts
@@ -654,8 +654,7 @@ class EdgeStyle {
         // of a floating port, or if the hint is exactly co-incident with a
         // fixed point, ignore the source and try to work out the orientation
         // from the target end
-        if (i == 0 && ((hozChan && vertChan) || (fixedVertAlign && fixedHozAlign))) {
-        } else {
+        if (!(i == 0 && ((hozChan && vertChan) || (fixedVertAlign && fixedHozAlign)))) {
           if (
             currentPt != null &&
             !fixedHozAlign &&