refactoring attempt

Author: davidfan168

src/index.tsx

@@ -589,28 +589,7 @@ class DiffViewer extends React.Component<
     };
   };
 
-  public render = (): ReactElement => {
-    const {
-      oldValue,
-      newValue,
-      useDarkTheme,
-      leftTitle,
-      rightTitle,
-      splitView,
-      compareMethod,
-      hideLineNumbers,
-      nonce,
-    } = this.props;
-
-    if (typeof(compareMethod) === 'string' && compareMethod !== DiffMethod.JSON) {
-      if (typeof oldValue !== 'string' || typeof newValue !== 'string') {
-        throw Error('"oldValue" and "newValue" should be strings');
-      }
-    }
-
-    this.styles = this.computeStyles(this.props.styles, useDarkTheme, nonce);
-    const nodes = this.renderDiff();
-
+  private calculateColSpans = (hideLineNumbers : boolean) => {
     let colSpanOnSplitView = 3;
     let colSpanOnInlineView = 4;
 
@@ -624,6 +603,10 @@ class DiffViewer extends React.Component<
       colSpanOnInlineView += 1;
     }
 
+    return [colSpanOnSplitView, colSpanOnInlineView]
+  }
+
+  private calculateChanges = (nodes) => {
     let deletions = 0, additions = 0
     nodes.lineInformation.forEach((l) => {
       if (l.left.type === DiffType.ADDED) {
@@ -639,6 +622,34 @@ class DiffViewer extends React.Component<
         deletions++
       }
     })
+    return [deletions, additions]
+  }
+
+  public render = (): ReactElement => {
+    const {
+      oldValue,
+      newValue,
+      useDarkTheme,
+      leftTitle,
+      rightTitle,
+      splitView,
+      compareMethod,
+      hideLineNumbers,
+      nonce,
+    } = this.props;
+
+    if (typeof(compareMethod) === 'string' && compareMethod !== DiffMethod.JSON) {
+      if (typeof oldValue !== 'string' || typeof newValue !== 'string') {
+        throw Error('"oldValue" and "newValue" should be strings');
+      }
+    }
+
+    this.styles = this.computeStyles(this.props.styles, useDarkTheme, nonce);
+    const nodes = this.renderDiff();
+
+    const [colSpanOnSplitView, colSpanOnInlineView] = this.calculateColSpans(hideLineNumbers)
+
+    const [deletions, additions] = this.calculateChanges(nodes)
     const totalChanges = deletions + additions
 
     const percentageAddition = Math.round((additions / totalChanges) * 100)

tsconfig.json

@@ -3,6 +3,7 @@
     "experimentalDecorators": true,
     "jsx": "react-jsx",
     "module": "commonjs",
+    "strict": true,
     "moduleResolution": "node",
     "noImplicitAny": true,
     "esModuleInterop": true,