refactor: use nullish coalescing assignment (#1229)

Co-authored-by: meteorlxy <meteor.lxy@foxmail.com>

Author: Mister-Hope

ecosystem/plugin-nprogress/src/client/nprogress.ts

@@ -224,7 +224,7 @@ const css = (function () {
 
   function getStyleProp(name: string): string {
     name = camelCase(name)
-    return cssProps[name] || (cssProps[name] = getVendorProp(name))
+    return (cssProps[name] ??= getVendorProp(name))
   }
 
   function applyCss(element: HTMLElement, prop: string, value: string): void {

packages/markdown/src/plugins/importCodePlugin/importCodePlugin.ts

@@ -40,8 +40,7 @@ export const importCodePlugin: PluginWithOptions<ImportCodePluginOptions> = (
 
     // extract imported files to env
     if (importFilePath) {
-      const importedFiles = env.importedFiles || (env.importedFiles = [])
-      importedFiles.push(importFilePath)
+      ;(env.importedFiles ??= []).push(importFilePath)
     }
 
     // render the import_code token as a fence token

packages/markdown/src/plugins/linksPlugin/linksPlugin.ts

@@ -130,8 +130,7 @@ export const linksPlugin: PluginWithOptions<LinksPluginOptions> = (
     hrefAttr[1] = `${normalizedPath}${rawHash}`
 
     // extract internal links for file / page existence check
-    const links = env.links || (env.links = [])
-    links.push({
+    ;(env.links ??= []).push({
       raw: hrefLink,
       relative: relativePath,
       absolute: absolutePath,