[Performance] Optimize Liquid template rendering

packages/cli-kit/src/public/node/liquid.test.ts

@@ -14,6 +14,28 @@ describe('create', () => {
     // Then
     expect(got).toEqual('test')
   })
+
+  test('returns static string as-is when no Liquid syntax is present', async () => {
+    // Given
+    const templateContent = 'plain text, no templates'
+
+    // When
+    const got = await renderLiquidTemplate(templateContent, {variable: 'test'})
+
+    // Then
+    expect(got).toEqual(templateContent)
+  })
+
+  test('renders strings with only block tags', async () => {
+    // Given
+    const templateContent = '{% if true %}yes{% endif %}'
+
+    // When
+    const got = await renderLiquidTemplate(templateContent, {})
+
+    // Then
+    expect(got).toEqual('yes')
+  })
 })
 
 describe('recursiveLiquidTemplateCopy', () => {

packages/cli-kit/src/public/node/liquid.ts

@@ -14,15 +14,31 @@ import {joinPath, dirname, relativePath} from './path.js'
 import {outputContent, outputToken, outputDebug} from './output.js'
 import {Liquid} from 'liquidjs'
 
+let liquidEngine: Liquid | undefined
+
+/**
+ * Returns a shared instance of the Liquid template engine.
+ *
+ * @returns Shared Liquid instance.
+ */
+function getLiquidEngine(): Liquid {
+  liquidEngine ??= new Liquid()
+  return liquidEngine
+}
+
 /**
  * Renders a template using the Liquid template engine.
  *
  * @param templateContent - Template content.
  * @param data - Data to feed the template engine.
  * @returns Rendered template.
  */
-export function renderLiquidTemplate(templateContent: string, data: object): Promise<string> {
-  const engine = new Liquid()
+export async function renderLiquidTemplate(templateContent: string, data: object): Promise<string> {
+  if (!templateContent.includes('{{') && !templateContent.includes('{%')) {
+    return templateContent
+  }
+
+  const engine = getLiquidEngine()
   return engine.render(engine.parse(templateContent), data)
 }