diff --git a/src/config.ts b/src/config.ts
new file mode 100644
index 0000000..38a6e66
--- /dev/null
+++ b/src/config.ts
@@ -0,0 +1,10 @@
+import * as vscode from 'vscode'
+
+export const getMaxCount = () =>
+    vscode.workspace.getConfiguration('hoverlens').get('maximumCursorCount', 3)
+
+export const getDebounceUpdate = () =>
+    vscode.workspace.getConfiguration('hoverlens').get('debounceUpdate', 50)
+
+export const getMaxShift = () =>
+    vscode.workspace.getConfiguration('hoverlens').get('maximumShiftCount', 20)
diff --git a/src/decoration.ts b/src/decoration.ts
index d346517..7215b95 100644
--- a/src/decoration.ts
+++ b/src/decoration.ts
@@ -4,16 +4,21 @@ import {
     removeEmptyLines,
     toPlainText,
 } from './formatting'
+import { getMaxCount, getMaxShift } from './config'
 
-export async function getDecorations(
+export type Decoration = {
+    editor: vscode.TextEditor
+    type: vscode.TextEditorDecorationType
+    line: number
+}
+
+export const getDecorations = async (
     editor: vscode.TextEditor,
     selections: readonly vscode.Selection[]
-) {
+) => {
     if (!selections.length) return []
 
-    const maxCount = vscode.workspace
-        .getConfiguration('hoverlens')
-        .get('maximumCursorCount', 3)
+    const maxCount = getMaxCount()
     if (maxCount > 0 && selections.length > maxCount) return []
 
     const positions = selections
@@ -33,9 +38,10 @@ export async function getDecorations(
         hovers.map(toPlainText).map(removeEmptyLines).join('\n').split('\n')
     )
 
-    const maxShift = vscode.workspace
-        .getConfiguration('hoverlens')
-        .get('maximumShiftCount', 20)
+    const maxShift = getMaxShift()
+
+    const getLineLength = (line: number) =>
+        editor.document.lineAt(line).range.end.character
 
     const layouts = positions.map((position, i) => {
         const paddings: number[] = []
@@ -67,26 +73,17 @@ export async function getDecorations(
         return texts
     })
 
-    return layouts
-        .map((paddings, i) =>
-            paddings.map(
-                (padding, j) =>
-                    [
-                        editor,
-                        createDecorationType(texts[i][j], padding),
-                        positions[i].line + j,
-                    ] as const
-            )
-        )
-        .flat()
-
-    function getLineLength(line: number) {
-        return editor.document.lineAt(line).range.end.character
-    }
+    return layouts.flatMap((paddings, i) =>
+        paddings.map((padding, j) => ({
+            editor,
+            type: createDecorationType(texts[i][j], padding),
+            line: positions[i].line + j,
+        }))
+    )
 }
 
-function createDecorationType(text: string, padding: number) {
-    return vscode.window.createTextEditorDecorationType({
+const createDecorationType = (text: string, padding: number) =>
+    vscode.window.createTextEditorDecorationType({
         after: {
             contentText: changeLeadingSpacesToNonBreaking(
                 ' '.repeat(padding) + text
@@ -97,4 +94,3 @@ function createDecorationType(text: string, padding: number) {
 
         isWholeLine: true,
     })
-}
diff --git a/src/extension.ts b/src/extension.ts
index 806ef87..231d789 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -1,41 +1,47 @@
 import * as vscode from 'vscode'
-import { getDecorations } from './decoration'
+import { Decoration, getDecorations } from './decoration'
 import { debounce } from './utils'
+import { getDebounceUpdate } from './config'
 
-export function activate(context: vscode.ExtensionContext) {
-    let tokenSource: vscode.CancellationTokenSource
-
-    let currentDecorations: Awaited<ReturnType<typeof getDecorations>> = []
-
-    const updateDecorations = debounce(
-        async (event: vscode.TextEditorSelectionChangeEvent) => {
-            tokenSource = new vscode.CancellationTokenSource()
-
-            const token = tokenSource.token
-            const decorations = await getDecorations(
-                event.textEditor,
-                event.selections
-            )
-            if (token.isCancellationRequested) return
-
-            currentDecorations.forEach(([, type]) => type.dispose())
-
-            currentDecorations = decorations
-            currentDecorations.forEach(([editor, type, line]) =>
-                editor.setDecorations(type, [
-                    new vscode.Selection(line, 0, line, 0),
-                ])
-            )
-        },
-        () =>
-            vscode.workspace
-                .getConfiguration('hoverlens')
-                .get('debounceUpdate', 50)
-    )
+let tokenSource: vscode.CancellationTokenSource | undefined
+const startUpdate = () => {
+    tokenSource = new vscode.CancellationTokenSource()
+    return tokenSource.token
+}
+const cancelUpdate = () => tokenSource?.cancel()
+
+let currentDecorations: Decoration[] = []
+const setDecorations = (decorations: Decoration[]) => {
+    for (const { type } of currentDecorations) {
+        type.dispose()
+    }
+
+    currentDecorations = decorations
+
+    for (const { editor, type, line } of currentDecorations) {
+        editor.setDecorations(type, [new vscode.Selection(line, 0, line, 0)])
+    }
+}
+
+const updateDecorations = debounce(
+    async (event: vscode.TextEditorSelectionChangeEvent) => {
+        const token = startUpdate()
+
+        const decorations = await getDecorations(
+            event.textEditor,
+            event.selections
+        )
+        if (token.isCancellationRequested) return
+
+        setDecorations(decorations)
+    },
+    getDebounceUpdate
+)
 
+export const activate = (context: vscode.ExtensionContext) => {
     context.subscriptions.push(
         vscode.window.onDidChangeTextEditorSelection((event) => {
-            tokenSource?.cancel()
+            cancelUpdate()
             updateDecorations(event)
         })
     )
diff --git a/src/formatting.ts b/src/formatting.ts
index 6d7f0eb..2546f1e 100644
--- a/src/formatting.ts
+++ b/src/formatting.ts
@@ -1,28 +1,24 @@
 import markdownToTxt from 'markdown-to-txt'
 import * as vscode from 'vscode'
 
-export function toPlainText(hover: vscode.Hover) {
-    return hover.contents
-        .map((content) => {
-            if (content instanceof vscode.MarkdownString) {
-                return markdownToTxt(content.value)
-            } else {
-                return typeof content === 'string'
-                    ? markdownToTxt(content)
-                    : content.value
-            }
-        })
+export const toPlainText = (hover: vscode.Hover) =>
+    hover.contents
+        .map((content) =>
+            content instanceof vscode.MarkdownString
+                ? markdownToTxt(content.value)
+                : typeof content === 'string'
+                ? markdownToTxt(content)
+                : content.value
+        )
         .join('\n')
-}
 
-export function removeEmptyLines(text: string) {
-    return text
+export const removeEmptyLines = (text: string) =>
+    text
         .split('\n')
         .filter((line) => !!line)
         .join('\n')
-}
 
-export function changeLeadingSpacesToNonBreaking(line: string) {
+export const changeLeadingSpacesToNonBreaking = (line: string) => {
     let i = 0
     for (; i < line.length; i++) {
         if (line[i] !== ' ') break
diff --git a/src/utils.ts b/src/utils.ts
index 3fe82f6..fec753e 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,8 +1,9 @@
-export function debounce<T extends (...args: never[]) => unknown>(
+export const debounce = <T extends (...args: never[]) => unknown>(
     fn: T,
     getMs: () => number
-) {
+) => {
     let timer: NodeJS.Timeout
+
     return (...args: Parameters<T>) => {
         clearTimeout(timer)