diff --git a/packages/docgen/src/compiler.ts b/packages/docgen/src/compiler.ts
index 3a196ca709..61837ad1f8 100644
--- a/packages/docgen/src/compiler.ts
+++ b/packages/docgen/src/compiler.ts
@@ -17,28 +17,28 @@
 import * as ts from 'typescript';
 import { resolve, join, dirname } from 'path';
 import { promisify } from 'util';
-import fs from 'fs';
+import fs from 'fs-extra';
 import ApiDocGenerator from './docgen/ApiDocGenerator';
 import sortSelector from './docgen/sortSelector';
 import TypeLocator from './docgen/TypeLocator';
 import ApiDocPrinter from './docgen/ApiDocPrinter';
 import TypescriptHighlighter from './docgen/TypescriptHighlighter';
 import MarkdownPrinter from './docgen/MarkdownPrinter';
-import { sync as mkdirpSync } from 'mkdirp';
 
 const writeFile = promisify(fs.writeFile);
 
 function loadOptions(path: string): ts.CompilerOptions {
-  let { extends: parent, compilerOptions }: any = require(path);
+  const config: any = require(path);
+  let parent = config.extends as string | undefined;
 
   if (!parent) {
-    return compilerOptions;
+    return config.compilerOptions;
   }
   if (parent.startsWith('.')) {
     parent = join(dirname(path), parent);
   }
 
-  return { ...loadOptions(parent), ...compilerOptions };
+  return { ...loadOptions(parent), ...config.compilerOptions };
 }
 
 async function main() {
@@ -84,7 +84,7 @@ async function main() {
     () => new MarkdownPrinter(new TypescriptHighlighter()),
   );
 
-  mkdirpSync(resolve(apiRefsDir, 'docs'));
+  fs.ensureDirSync(resolve(apiRefsDir, 'docs'));
 
   await Promise.all(
     apiDocs.map(apiDoc => {
diff --git a/packages/docgen/src/docgen/ApiDocGenerator.ts b/packages/docgen/src/docgen/ApiDocGenerator.ts
index e1d1e0f5f1..1142f1155e 100644
--- a/packages/docgen/src/docgen/ApiDocGenerator.ts
+++ b/packages/docgen/src/docgen/ApiDocGenerator.ts
@@ -116,18 +116,18 @@ export default class ApiDocGenerator {
     objectLiteral: ts.ObjectLiteralExpression,
     propertyName: string,
   ): string {
-    const prop = objectLiteral.properties.filter(
+    const matchingProp = objectLiteral.properties.filter(
       prop =>
         ts.isPropertyAssignment(prop) &&
         ts.isIdentifier(prop.name) &&
         prop.name.text === propertyName,
     )[0] as ts.PropertyAssignment;
 
-    if (!prop) {
+    if (!matchingProp) {
       throw new Error(`no identifier found for property ${propertyName}`);
     }
 
-    const { initializer } = prop;
+    const { initializer } = matchingProp;
     if (!ts.isStringLiteral(initializer)) {
       throw new Error(`no string literal for ${propertyName}`);
     }
@@ -238,22 +238,22 @@ export default class ApiDocGenerator {
     type: ts.Type | undefined,
   ): undefined | { symbol: ts.Symbol; declaration: ts.Declaration } {
     if (!type) {
-      return;
+      return undefined;
     }
     const symbol = type.aliasSymbol || type.symbol;
     if (!symbol) {
-      return;
+      return undefined;
     }
 
     const [declaration] = symbol.declarations;
 
     // Don't generate standalone infos for type paramters
     if (ts.isTypeParameterDeclaration(declaration)) {
-      return;
+      return undefined;
     }
 
     if (!declaration.getSourceFile().fileName.startsWith(this.sourcePath)) {
-      return;
+      return undefined;
     }
 
     return { symbol, declaration };
diff --git a/packages/docgen/src/docgen/MarkdownPrinter.ts b/packages/docgen/src/docgen/MarkdownPrinter.ts
index c33ecc76a8..36e7c8b1d6 100644
--- a/packages/docgen/src/docgen/MarkdownPrinter.ts
+++ b/packages/docgen/src/docgen/MarkdownPrinter.ts
@@ -108,7 +108,7 @@ export default class MarkdownPrinter {
 
     const parts: Array<{ text: string; path?: string }> = [];
 
-    const end = sortedLinks.reduce((prev, link) => {
+    const endLocation = sortedLinks.reduce((prev, link) => {
       const [start, end] = link.location;
       parts.push(
         { text: text.slice(prev, start) },
@@ -117,15 +117,14 @@ export default class MarkdownPrinter {
       return end;
     }, 0);
 
-    parts.push({ text: text.slice(end) });
+    parts.push({ text: text.slice(endLocation) });
 
     return parts
       .map(part => {
         if (part.path) {
           return `<a href="#${part.path}">${this.escapeText(part.text)}</a>`;
-        } else {
-          return this.highlighter.highlight(this.escapeText(part.text));
         }
+        return this.highlighter.highlight(this.escapeText(part.text));
       })
       .join('');
   }
diff --git a/packages/docgen/src/docgen/TypeLocator.ts b/packages/docgen/src/docgen/TypeLocator.ts
index 8342548e01..b960640559 100644
--- a/packages/docgen/src/docgen/TypeLocator.ts
+++ b/packages/docgen/src/docgen/TypeLocator.ts
@@ -95,30 +95,30 @@ export default class TypeLocator {
     | { constructorType: ts.Type; initializer: ts.NewExpression; name: string }
     | undefined {
     if (!ts.isVariableStatement(node)) {
-      return;
+      return undefined;
     }
     if (
       !node.modifiers ||
       !node.modifiers.some(mod => mod.kind === ts.SyntaxKind.ExportKeyword)
     ) {
-      return;
+      return undefined;
     }
     const { declarations } = node.declarationList;
     if (declarations.length !== 1) {
-      return;
+      return undefined;
     }
 
     const [declaration] = declarations;
     const { initializer, name } = declaration;
 
     if (!initializer || !name) {
-      return;
+      return undefined;
     }
     if (!ts.isNewExpression(initializer)) {
-      return;
+      return undefined;
     }
     if (!ts.isIdentifier(name)) {
-      return;
+      return undefined;
     }
 
     const constructorType = this.checker.getTypeAtLocation(
diff --git a/packages/docgen/src/docgen/TypescriptHighlighter.ts b/packages/docgen/src/docgen/TypescriptHighlighter.ts
index a16c9a2c28..4bbb6548dd 100644
--- a/packages/docgen/src/docgen/TypescriptHighlighter.ts
+++ b/packages/docgen/src/docgen/TypescriptHighlighter.ts
@@ -56,7 +56,7 @@ export default class TypescriptHighlighter implements Highlighter {
     ], // keywords
   ] as readonly [RegExp, string][];
 
-  highlight(text: string): string {
+  highlight(fullText: string): string {
     // Each part is either plain text that can be highlighted or text that is already highlighted
     type HighlightPart = { text: string; highlighted?: boolean };
 
@@ -80,7 +80,7 @@ export default class TypescriptHighlighter implements Highlighter {
     // Order here is important, e.g. comments must be first to avoid string literals inside comments being highlighted
     return TypescriptHighlighter.highlighters
       .reduce((parts, highlighter) => flatMap(parts, painter(...highlighter)), [
-        { text },
+        { text: fullText },
       ])
       .map(({ text }) => text)
       .join('');
diff --git a/packages/docgen/src/docgen/sortSelector.ts b/packages/docgen/src/docgen/sortSelector.ts
index 1ba7a7918d..7590ae39ec 100644
--- a/packages/docgen/src/docgen/sortSelector.ts
+++ b/packages/docgen/src/docgen/sortSelector.ts
@@ -21,14 +21,13 @@ export default function sortSelector<T>(
   selector: (x: T) => any,
 ): (a: T, b: T) => -1 | 1 | 0 {
   return (a: T, b: T) => {
-    let aV = selector(a);
-    let bV = selector(b);
+    const aV = selector(a);
+    const bV = selector(b);
     if (aV < bV) {
       return -1;
     } else if (aV > bV) {
       return 1;
-    } else {
-      return 0;
     }
+    return 0;
   };
 }